Paramount Gold Nevada (NYSE American: PZG) posts $374.7M NPV for Grassy Mountain

Rhea-AI Filing Summary

Paramount Gold Nevada Corp. filed an updated S‑K 1300 technical report summary and feasibility study for its Grassy Mountain underground gold‑silver project in Oregon, effective May 27, 2026. The update revises mineral resources, mineral reserves, capital and operating costs, and the economic analysis.

The study reports proven and probable underground reserves of 2,207,000 tons grading 0.184 oz/ton gold and 0.283 oz/ton silver, containing 405,000 oz of gold and 625,000 oz of silver. Planned mine life is 9.3 years, feeding a 750‑ton‑per‑day plant with average annual gold production of 41.4 thousand oz.

Initial capital is estimated at $189.8 million with life‑of‑mine cash costs of $1,217.95/oz and all‑in sustaining costs of $1,441.57/oz, net of by‑products. Using long‑term prices of $3,600/oz gold and $48.00/oz silver, the project delivers a post‑tax NPV5% of $374.7 million, a 38.9% IRR and a 2.2‑year payback. Federal permitting includes a final Environmental Impact Statement and record of decision, with state permits anticipated in the third quarter of 2026.

Positive

• The updated study reports a post‑tax NPV5% of $374.7 million, a 38.9% IRR and a 2.2‑year payback at base‑case gold and silver prices.
• Project permitting is advanced, with a final BLM Environmental Impact Statement and record of decision issued on January 29, 2026 and final state permits anticipated in the third quarter of 2026.

Negative

• None.

8-K Event Classification

2 items: 8.01, 9.01

2 items

Item 8.01 Other Events Other

Voluntary disclosure of events the company deems important to shareholders but not covered by other items.

Item 9.01 Financial Statements and Exhibits Exhibits

Financial statements, pro forma financial information, and exhibit attachments filed with this report.

Key Figures

Measured + Indicated resources: 57,794,000 tons at 0.023 oz/ton Au and 0.077 oz/ton Ag Proven & Probable reserves: 2,207,000 tons at 0.184 oz/ton Au and 0.283 oz/ton Ag Initial capital cost: $189.8 million +5 more

8 metrics

Measured + Indicated resources 57,794,000 tons at 0.023 oz/ton Au and 0.077 oz/ton Ag Grassy Mountain mineral resources inclusive of reserves, effective February 28, 2026

Proven & Probable reserves 2,207,000 tons at 0.184 oz/ton Au and 0.283 oz/ton Ag Underground mineral reserves for Grassy Mountain, effective May 15, 2026

Initial capital cost $189.8 million Initial project capital including contingency, reported in Q2 2026 USD

All-in sustaining cost (AISC) $1,441.57 per oz Au Life-of-mine AISC net of by-products for Grassy Mountain

Post-tax NPV5% $374.7 million Net present value at 5% discount rate using $3,600/oz Au and $48.00/oz Ag

Post-tax IRR 38.9% Unlevered internal rate of return on a post-tax basis for the project

Average annual gold production 41.4 thousand oz Au Average yearly recovered gold over the 9.3-year mine life

Mine life 9.3 years Planned life-of-mine for the Grassy Mountain underground operation

Key Terms

all-in sustaining cost (AISC), net present value (NPV), net smelter return (NSR), gold equivalent (AuEq), +2 more

6 terms

all-in sustaining cost (AISC) financial

"**AISC net of by-products | | $/oz Au | | 1,441.57"

All-in sustaining cost (AISC) is a per-unit measure of what a mining operation spends to produce its commodity, including routine operating expenses plus the ongoing capital and maintenance needed to keep the operation running. Investors use AISC to compare true production costs across companies and judge profitability and cash flow resilience—think of it like the total cost per mile to operate a car, not just the fuel.

net present value (NPV) financial

"Post-tax NPV, 5% | | $M | | 374.7"

Net present value (NPV) measures the current worth of a series of future cash flows from an investment after subtracting the money put in today, using an interest rate to reflect time and risk. Investors use NPV to decide whether a project should go ahead: a positive NPV means the expected returns are worth more than the cost, like choosing between getting cash now or a bigger, but less valuable, pile of money later once you account for time and uncertainty.

net smelter return (NSR) financial

"Cryla is entitled to a 2% net smelter return (NSR)"

A net smelter return (NSR) is a royalty payment equal to a fixed percentage of the money received from selling mined metals after they have been processed and refined; it’s calculated on the final proceeds rather than on the raw ore. For investors, NSRs matter because they create a predictable, passive revenue stream tied to metal sales—like receiving a slice of the final sale price after a craftsman turns raw material into a finished product—affecting valuation, cash flow and risk exposure to production and metal prices.

gold equivalent (AuEq) technical

"a gold equivalent (AuEq) cut-off grade of 0.008 oz/ton AuEq"

carbon-in-leach (CIL) technical

"a hybrid leach/carbon-in-leach (CIL) recovery circuit via a pre-aeration tank"

A carbon-in-leach (CIL) process is a mineral processing method where valuable metals, most often gold, are dissolved from crushed ore by a chemical solution and simultaneously captured onto pieces of activated carbon within the same tanks. It matters to investors because CIL can improve metal recovery and simplify plant design—like using a tea bag that soaks up flavor while the tea steeps—affecting production forecasts, capital and operating costs, and environmental management.

Feasibility Study (FS) technical

"compiled an updated technical report summary on a feasibility study (the FS)"

A feasibility study is a structured assessment that tests whether a planned project, product or transaction is technically possible, financially viable and likely to meet regulatory and market requirements. It matters to investors because it quantifies risks, estimated costs, timelines and potential returns—like a detailed road test and budget before building a house—helping decide whether to fund, value, or walk away from an opportunity.

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FAQ

What did Paramount Gold Nevada (PZG) disclose about the Grassy Mountain project?

Paramount Gold Nevada filed an updated S‑K 1300 technical report and feasibility study for the Grassy Mountain underground gold‑silver project, effective May 27, 2026, revising mineral resources, reserves, capital and operating costs, and the overall economic analysis.

What are the updated mineral reserves for PZG’s Grassy Mountain project?

The study estimates total proven and probable reserves of 2,207,000 tons grading 0.184 oz/ton Au and 0.283 oz/ton Ag, containing 405,000 oz of gold and 625,000 oz of silver for the underground mine plan.

What mine life and production profile are outlined for PZG’s Grassy Mountain project?

The plan outlines a 9.3‑year underground operation feeding a 750 tons/day plant, with average annual recovered production of about 41.4 thousand oz of gold and 51.5 thousand oz of silver over the life of mine.

What capital and operating costs are estimated for Paramount Gold Nevada’s Grassy Mountain mine?

Initial capital is estimated at $189.8 million, plus $65.1 million sustaining and $21.1 million closure costs. Life‑of‑mine operating costs average $198.96/ton processed, with cash costs of $1,217.95/oz and AISC of $1,441.57/oz of gold.

What are the projected economics (NPV and IRR) for PZG’s Grassy Mountain project?

At base‑case prices of $3,600/oz Au and $48.00/oz Ag, the project generates a post‑tax NPV5% of $374.7 million, a post‑tax IRR of 38.9%, and a post‑tax unlevered free cash flow of $540.7 million over the mine life.

What is the permitting status of Paramount Gold Nevada’s Grassy Mountain project?

BLM issued the final Environmental Impact Statement and record of decision on January 29, 2026. Draft state permits have completed public comment, and final state permits are anticipated in the third quarter of 2026, following cultural-resource coordination.

What price assumptions underpin the updated economic analysis for PZG’s Grassy Mountain project?

The economic analysis uses long‑term flat prices of $3,600/oz for gold and $48.00/oz for silver. These assumptions drive forecast gross revenue of $1,410.6 million and support the reported NPV, IRR and payback metrics.

false 0001629210 0001629210 2026-07-14 2026-07-14

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): July 14, 2026

Paramount Gold Nevada Corp.

(Exact name of Registrant as Specified in Its Charter)

Nevada		001-36908		98-0138393
(State or Other Jurisdiction of Incorporation)		(Commission File Number)		(IRS Employer Identification No.)
665 Anderson Street
Winnemucca, Nevada				89445
(Address of Principal Executive Offices)				(Zip Code)

Registrant’s Telephone Number, Including Area Code: 775 625-3600

(Former Name or Former Address, if Changed Since Last Report)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

☐ Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

☐ Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

☐ Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

☐ Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Securities registered pursuant to Section 12(b) of the Act:

Title of each class		Trading Symbol(s)		Name of each exchange on which registered
Common Stock, $0.01 Par Value Per Share		PZG		NYSE American LLC

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§ 230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b-2 of this chapter).

Emerging growth company ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Item 8.01 Other Events

On July 14, 2026, Paramount Gold Nevada Corp. (the “Company”) filed a technical report summary, effective as of May 27, 2026, which had been prepared in accordance with the requirements of subpart 1300 of Regulation S-K, for its Grassy Mountain Gold Project (the “Report”). The Report and the corresponding consent of the “Qualified Persons” are filed as Exhibits 99.1, 23.1, 23.2, 23.3, 23.4 and 23.5, respectively, to this Current Report on Form 8-K and are incorporated herein by reference.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits.

Exhibit Number		Description
23.1		Consent of Qualified Person – Ausenco Engineering Canada Inc.
23.2		Consent of Qualified Person – RESPEC Company LLC
23.3		Consent of Qualified Person – WSP USA Inc.
23.4		Consent of Qualified Person – Geotechnical Mine Solutions
23.5		Consent of Qualified Person – SLR International Corporation
99.1		Technical Report Summary for the Grassy Mountain Gold Project effective May 26, 2026.
104		Cover Page Interactive Data File (embedded within the Inline XBRL document)

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

						Paramount Gold Nevada Corp.
Date: July 14, 2026				By:		/s/ Rachel Goldman
						Rachel Goldman, Chief Executive Officer

Exhibit 99.1

Date and Signature Page

This technical report summary (the TRS), entitled “Grassy Mountain Project: S-K 1300 Technical Report Summary, Oregon, United States of America” is current as of May 27, 2026 and has been prepared by:

Qualified Person or Firm		Responsible for the following sections		Signature		Date
Ausenco Engineering Canada ULC		1.1, 1.10, 1.16, 1.17.1, 1.18, 1.20, 1.21, 1.22, 2.1, 2.2, 2.3, 2.4.1, 2.5, 2.6, 2.7, 2.8, 9.2.1, 9.3.1, 10, 13.3, 14, 15.1, 15.2, 15.7.3, 15.8, 15.9, 15.10, 16, 18.1.1, 18.1.2, 18.1.3, 18.1.4, 18.1.5, 18.1.6, 18.1.7, 18.1.9, 18.1.10.2, 18.1.11, 18.1.12, 18.1.13, 18.2.1, 18.2.3, 18.2.4, 19, 22.1, 22.6, 22.11, 22.12.1, 22.12.2, 22.12.6, 22.13, 22.15, 22.16, 22.17, 22.18.1.2, 22.18.1.5, 22.18.1.9, 22.18.1.10, 22.18.2.2, 23.1, 23.2, 23.7, 24, 25		“signed”		July 14, 2026
Geotechnical Mine Solutions Inc.		2.4.2, 13.2, 13.4, 13.5, 13.6, 13.11.6, 22.10, 23.5, 24		“signed”		July 14, 2026
RESPEC Company LLC (Geology and Resources)		1.5, 1.6, 1.7, 1.8, 1.9, 1.11, 1.12, 2.4.3, 5, 6, 7, 8, 9.1, 9.2.2, 9.3.2, 11, 22.3, 22.4, 22.5, 22.7, 22.18.1.1, 22.18.1.3, 22.18.2.1, 23.3, 24, 25.2, 25.3, 25.5		“signed”		July 14, 2026
RESPEC Company LLC (Mine Engineering)		1.13, 1.14, 1.15, 2.4.3, 12, 13.1, 13.7, 13.8, 13.9, 13.10, 13.11.1, 13.11.2, 13.11.3, 13.11.4, 13.11.5, 13.11.7, 13.11.8, 13.12, 13.13, 13.14, 18.1.8, 18.2.2, 22.8, 22.9, 22.18.1.4, 22.18.1.7, 22.18.1.8, 22.18.2.3, 22.18.2.4, 22.18.2.6, 22.18.2.7, 23.4, 24, 25.2, 25.3, 25.5		“signed”		July 14, 2026
SLR International Corporation		1.19, 2.4.4, 3.5, 9.2.3, 9.3.3, 17, 18.1.14, 22.14, 22.18.1.6, 22.18.2.5, 23.6, 23.8, 24, 25.2, 25.3		“signed”		July 14, 2026
WSP USA Inc.		1.17.2, 1.17.3, 1.17.4, 1.17.5, 2.4.5, 15.3, 15.4, 15.5, 15.6, 15.7.1, 15.7.2, 18.1.10.1, 22.12.3, 22.12.4, 22.12.5, 24, 25.2, 25.3		“signed”		July 14, 2026
Paramount Gold Nevada Corp.		1.2, 1.3, 1.4, 3.1, 3.2, 3.3, 3.4, 3.6, 3.7, 3.8, 4, 20, 21, 22.2		“signed”		July 14, 2026

Table of Contents

1  Executive Summary			1
1.1  Introduction			1
1.1.1  Terms of Reference			1
1.1.2  Effective Dates			1
1.2  Property Description			2
1.3  Mineral Tenure, Surface Rights, Water Rights, Royalties and Agreements			2
1.4  Accessibility, Climate, Local Resources, Infrastructure and Physiography			3
1.5  History			3
1.6  Geological Setting, Mineralization and Deposit			4
1.7  Exploration			4
1.8  Sample Preparation, Analyses and Security			5
1.9  Data Verification			6
1.10  Mineral Processing and Metallurgical Testwork			7
1.11  Mineral Resource Estimate			8
1.12  Mineral Resource Statement			10
1.13  Mineral Reserve Estimate			10
1.14  Mineral Reserve Statement			12
1.15  Mining Methods			12
1.15.1 Overview			12
1.15.2 Mine Design			13
1.15.3 Mine Production Plan			14
1.16  Processing and Recovery Methods			15
1.17  Infrastructure			18
1.17.1 Overview			18
1.17.2 Temporary Waste Rock Storage Facilities (TWRSF) and Borrow Pits			18
1.17.3 Tailings Storage Facility			18
1.17.4 Water Management			19
1.17.5 Water Balance			19
1.18  Market Studies and Contracts			19
1.19  Environmental, Permitting and Social Considerations			20
1.19.1 Environmental Considerations			20
1.19.2 Permitting Considerations			20

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page i May 27, 2026

1.19.3 Social Considerations			20
1.19.4 Closure and Reclamation Considerations			20
1.20  Capital and Operating Cost			20
1.20.1 Capital Cost Estimate			20
1.20.2 Operating Cost Estimate			21
1.21  Economic Analysis			22
1.21.1 Economic Summary			22
1.21.2 Sensitivity Analysis			23
1.22  Conclusions			23
2  Introduction			24
2.1  Introduction			24
2.2  Terms of Reference			24
2.3  Qualified Persons (QP)			24
2.4  Site Visits and Scope of Personal Inspection			25
2.4.1  Site Inspection by the Qualified Person of Ausenco			25
2.4.2  Site Inspection by the Qualified Person of GMS			25
2.4.3  Site Inspection by the Qualified Persons of RESPEC			26
2.4.4  Site Inspection by the Qualified Person of SLR			26
2.4.5  Site Inspection by the Qualified Person of WSP			26
2.5  Effective Dates			26
2.6  Information Sources and References			27
2.7  Previous Technical Reports			27
2.8  Currency, Units, Abbreviations and Definitions			28
3  Property Description			34
3.1  Introduction			34
3.2  Mineral Tenure			35
3.2.1  Mineral Concession Payment Terms			35
3.2.2  Land Access and Ownership Agreements			35
3.2.3  Seabridge Gold Corporation			35
3.2.4  Sherry and Yates, Inc.			36
3.2.5  Cryla LLC			36
3.3  Royalties and Additional Encumbrances			37
3.3.1  Seabridge Gold			37
3.3.2  Sherry and Yates			37
3.3.3  Cryla			38
3.3.4  Other Encumbrances			38

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page ii May 27, 2026

3.4  Environmental Liabilities			38
3.5  Environmental Permitting			38
3.6  Surface Rights			39
3.7  Water Rights			39
3.8  Summary Statement			39
4  Accessibility, Climate, Local Resources, Infrastructure and Physiography			40
4.1  Access			40
4.2  Physiography			41
4.3  Climate			42
4.4  Water Supply			42
4.5  Power			42
4.6  Infrastructure			42
4.7  Community Services			42
5  History			44
5.1  Introduction			44
5.2  1986-1996 Exploration			44
5.2.1  Atlas 1986-1992			44
5.2.2  Newmont 1992-1996			45
5.2.3  1996 Exploration at Outlying Targets within the Grassy Mountain Claims Group			45
5.3  1998-2016 Exploration			48
5.3.1  Tombstone 1998			48
5.3.2  Seabridge 2000-2010			48
5.3.3  Calico 2011-2016			49
5.4  Production			50
6  Geological Setting, Mineralization and Deposit			51
6.1  Introduction			51
6.2  Regional Geologic Setting			51
6.3  Local and Project Geology			51
6.4  Grassy Mountain Deposit			54
6.4.1  Geology			54
6.4.2  Structure			56
6.4.3  Alteration and Mineralization			56
6.5  Deposit Types			58

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page iii May 27, 2026

7  Exploration			60
7.1  Exploration			60
7.2  Drilling			62
7.2.1  Historical Drilling, 1987-2012			66
7.2.2  Paramount 2016–2019			68
7.3  Drill-Hole Collar and Down-Hole Surveys			71
7.4  Sample Quality			72
7.4.1  Core Samples			72
7.4.2  RC Samples			74
7.5  Summary Statement			75
8  Sample Preparation, Analyses, and Security			76
8.1  Introduction			76
8.2  Sample Preparation, Analysis and Security			76
8.2.1  Atlas 1987-1992			76
8.2.2  Newmont 1992-1996			76
8.2.3  Tombstone 1998			77
8.2.4  Calico 2011-2012			77
8.2.5  Paramount 2016-2019			79
8.3  Quality Assurance/Quality Control Procedures			79
8.3.1  Atlas QA/QC, 1987–1992			79
8.3.2  Newmont QA/QC, 1992–1996			80
8.3.3  Tombstone QA/QC, 1998			80
8.3.4  Calico QA/QC, 2011–2012			81
8.3.5  Paramount QA/QC, 2016–2019			81
8.4  Quality Assurance/Quality Control Results			82
8.4.1  Atlas, 1987–1992			82
8.4.2  Newmont, 1992–1996			87
8.4.3  Tombstone 1998			89
8.4.4  Calico, 2011–2012			90
8.4.5  Paramount 2016–2017			93
8.4.6  Paramount 2018–2019			100
8.4.7  Discussion of QA/QC Results			100
8.5  Summary Statement			100

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page iv May 27, 2026

9  Data Verification			101
9.1  Drill-Hole Data			101
9.1.1  Collar Data			101
9.1.2  Down-Hole Survey Data			102
9.1.3  Assay Data			102
9.1.4  Additional Data Verification			103
9.2  Site and Field Office Inspections			103
9.2.1  Ausenco			103
9.2.2  RESPEC			103
9.2.3  SLR			104
9.3  Summary Statement			104
9.3.1  Ausenco			104
9.3.2  RESPEC			104
9.3.3  SLR			105
10  Mineral Processing and Metallurgical Testing			106
10.1  Introduction			106
10.2  Historical Testwork Programs			107
10.2.1 Historical Studies 1989 to 2012			107
10.2.2 Historical Testwork from 2018 PFS			107
10.3  2020 FS Testwork			108
10.3.1 Objectives			108
10.3.2 SGS Testwork Program 15944-002 Scope of Work			108
10.3.3 McClelland Testwork Program MLI 4551 Scope of Work			108
10.3.4 Sample Selection for SGS Program 15944-02			108
10.3.5 Sample Selection for McClelland Program MLI 4551			109
10.4  Presentation and Discussion of Results			110
10.4.1 Ore Characterization and Deleterious Elements			110
10.4.2 Comminution Test Results			111
10.4.3 Mineralogical Analysis			112
10.4.4 Leach Tests			113
10.4.5 Cyanide Destruction			118
10.5  Metallurgical Variability			119
10.5.2 Sample Selection for SGS Program 15944-02			120
10.5.3 Sample Selection for McClelland Program MLI 4551			120

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page v May 27, 2026

10.6  Recovery Estimation			120
10.6.1 Leach Recovery, SGS Program 15944-001, SGS Program 15944-002 and McClelland Program MLI 4551			120
10.7  Summary			126
10.8  Qualified Person’s Opinion on Data Adequacy			127
11  Mineral Resource Estimates			128
11.1  Introduction			128
11.2  Grassy Mountain project Data			128
11.2.1 Drill-Hole Database			128
11.2.2 Topography			128
11.3  Deposit Geology Relevant to Resource Modelling			128
11.4  Geologic Modeling			130
11.5  Water Table and Oxidation Modeling			130
11.6  Density Modeling			130
11.7  Gold and Silver Modeling			131
11.7.1 Mineral Domains			131
11.7.2 Assay Coding, Capping, and Compositing			137
11.7.3 Block Model Coding			139
11.7.4 Grade Interpolation			139
11.7.5 Model Checks			141
11.8  Grassy Mountain Mineral Resources			141
11.8.1 Pit Optimizations, Cutoff Grades and Reporting Prices			141
11.8.2 Mineral Resources			143
11.8.3 Classification			150
11.9  Additional Comments on the Modeling of the Mineral Resources			152
12  Mineral Reserve Estimates			153
12.1  Introduction			153
12.1.1 Estimation Procedure			153
12.2  Mineral Reserve Statement			154
12.3  Economic Cut-off Grade Calculation			154
12.3.1 Gold Price			154
12.3.2 Silver Price			156
12.4  Stope Design			156
12.5  Dilution and Recovery			158
12.5.1 External Dilution			158

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page vi May 27, 2026

12.5.2 Internal Dilution			159
12.5.3 Mining Recovery			159
12.6  Discussion of Mineral Reserves			159
12.7  Classification			159
13  Mining Methods			161
13.1  Mining Method Selection			161
13.1.1 Underhand Mechanized Cut-and-Fill Mining			161
13.1.2 Mining Method Sequence			165
13.2  Geotechnical Analysis			167
13.2.1 Overview			167
13.2.2 Geotechnical Characterization			168
13.2.3 Golder Geotechnical Appraisal			169
13.2.4 Ausenco Geotechnical Work			171
13.2.5 Feasibility Study Geotechnical Analysis			173
13.2.6 Geotechnical Model			176
13.2.7 Summary of Geotechnical Analysis and Evaluation for Underground Mining			178
13.3  Hydrogeological modelling			178
13.4  Excavation Design			178
13.4.1 Mining Method Selection			178
13.4.2 Drift Sizes and Stability Assessments			179
13.5  Numerical Modelling			182
13.5.1 Ground Support			189
13.5.2 Ground Monitoring Program			190
13.5.3 Global Extraction Sequence			190
13.6  Portal Design			191
13.7  Grade Control			192
13.8  Personnel			192
13.9  Development Design			192
13.9.1 Mine Design Parameters			192
13.9.2 Level Access			193
13.9.3 Station Design			194
13.10 Equipment Selection			195
13.11  Production and Development Productivity Assumptions			195
13.11.1 Drilling and Bolting			195
13.11.2 Shotcrete			197

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13.11.3 Blasting		200
13.11.4 Mucking		200
13.11.5 Hauling		201
13.11.6 Backfilling		203
13.11.7 Backfill Plant		206
13.11.8 Production Scheduling		208
13.12 Underground Infrastructure and Services		209
13.12.1 Ventilation		209
13.12.2 Underground Dewatering		211
13.12.3 Underground Power		212
13.12.4 Underground Communications		213
13.12.5 Underground Refuge and Escape Ways		213
13.13 Mining Costs		214
13.14 Life-of-Mine Production		214
14  Processing and Recovery Methods		220
14.1  Introduction		220
14.2  Process Design Criteria		220
14.3  Process Flowsheet Development		222
14.4  Overall Process Description		225
14.4.1 Crushing Circuit		225
14.4.2 Grinding Circuit		226
14.4.3 Leach/CIL		226
14.4.4 Carbon Management		227
14.4.5 Gold Room		228
14.4.6 Cyanide Detoxification and Tailings Deposition		229
14.4.7 Reagent Handling and Storage		229
14.4.8 Air Supply and Distribution		231
14.4.9 Water Supply and Distribution		231
14.5  Personnel		232
14.6  Sampling and Metallurgical Laboratory		232
14.7  Projected Energy Requirements		232
14.8  Project Water Requirements		232

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15  Infrastructure			234
15.1  Introduction			234
15.2  Access			236
15.3  Temporary Waste Rock Storage Facility (TWRSF)			236
15.4  Basalt Borrow Quarry			236
15.5  Tailings Storage Facility			237
15.5.1 Topography, Drainage, and Vegetation			239
15.5.2 Past Studies, Subsurface Investigations, and Civil Design			239
15.5.3 Design Objectives			240
15.5.4 TSF Design			241
15.5.5 Monitoring			243
15.5.6 Closure			244
15.6  Closure Cover Borrow Areas			245
15.7  Water Management			245
15.7.1 Non-Contact Water Management			245
15.7.2 Contact Water Management			247
15.7.3 Site-wide Water Balance			249
15.8  Built Infrastructure			250
15.9  Camps and Accommodation			251
15.10 Power and Electrical			251
16  Market Studies			252
16.1  Introduction			252
16.2  Market Studies			252
16.3  Metal Pricing and Projections			252
16.3.1 Economic Analysis			252
16.3.2 Metal Pricing Forecasts			253
16.4  Contracts			254
16.5  QP Comment			254
17  Environmental Studies, Permitting, Plans, Negotiations or Agreements with Local Individuals or Groups			255
17.1  Introduction			255
17.2  Permit History			257
17.3  Project Permits			257
17.4  State of Oregon Permit Processing			257
17.4.1 Federal Plan of Operations Processing			260
17.4.2 Malheur County Permit Processing			261
17.5  Environmental Study Results and Known Issues			261
17.5.1 Baseline Studies			261
17.5.2 Geochemical Characterization and Groundwater Studies			263

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17.6  Waste Disposal, Monitoring, Water Management			264
17.7  Social and Community Issues			265
17.8  Closure			265
17.9  Environmental and Permitting Risks and Opportunities			266
17.10 Qualified Person’s Opinion			267
18  Capital and Operating Costs			268
18.1  Capital Cost Estimate			268
18.1.1 Introduction			268
18.1.2 Cost Estimate Summary – Initial Capital			269
18.1.3 Cost Estimate Summary – Sustaining Capital			271
18.1.4 Definition of Costs			271
18.1.5 Methodology			272
18.1.6 Exchange Rates			272
18.1.7 Market Availability			271
18.1.8 Mining Capital Cost Estimate			271
18.1.9 Processing and Overall Site Infrastructure Capital Cost Estimate			276
18.1.10 Tailings Storage and Temporary Waste Rock Storage Facilities Capital Cost Estimate			281
18.1.11 Indirect Capital Cost Estimate			282
18.1.12 Owner’s Costs			284
18.1.13 Contingency			285
18.1.14 Reclamation and Closure Capital Cost Estimate			285
18.2  Operating Cost Estimate			285
18.2.1 Summary and Basis of Operating Cost Estimate			285
18.2.2 Mining Operating Cost Estimate			286
18.2.3 Process Operating Cost Estimate			288
18.2.4 General and Administrative Operating Cost Estimate			291
19  Economic Analysis			292
19.1  Forward-Looking Information			292
19.2  Methodology Used			293
19.3  Financial Model Parameters			294
19.4  Taxes			294
19.5  Royalty			294
19.6  Economic Analysis			295
19.7  Sensitivity Analysis			299
19.8  Conclusion – Economic Analysis			302

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20  Adjacent Properties			303
21  Other Relevant Data and Information			304
22  Interpretation and Conclusions			305
22.1  Introduction			305
22.2  Mineral Tenure, Surface Rights, Water Rights, Royalties and Agreements			305
22.3  Geology and Mineralization			305
22.4  Exploration			306
22.5  Analytical Data Collection in Support of Mineral Resource Estimation			306
22.6  Metallurgical Testwork			306
22.7  Mineral Resource Estimation			307
22.8  Mineral Reserve Estimates			308
22.9  Mining Method			308
22.10 Geotechnical Considerations			309
22.11 Processing and Recovery Methods			310
22.12 Infrastructure			310
22.12.1 Key Infrastructure			310
22.12.2 Roads and Power			310
22.12.3 Waste Rock Storage and Borrow Pits			310
22.12.4 Tailings Storage Facility			310
22.12.5 Water Management			311
22.12.6 Water Supply			311
22.13 Markets and Contracts			311
22.14 Environmental, Permitting and Social Considerations			312
22.15 Capital Cost Estimate			312
22.16 Operating Cost Estimate			313
22.17 Economic Analysis			313
22.18 Risks and Opportunities			314
22.18.1 Risks			314
22.18.2 Opportunities			317
23  Recommendations			319
23.1  Introduction			319
23.2  Metallurgical Testing			319
23.3  Mineral Resource Estimate			319
23.4  Mining Methods			320

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23.5  Geotechnical			321
23.6  Hydrology			323
23.7  Infrastructure			323
23.8  Environmental Studies, Permitting and agreements with local individuals or groups			324
24  References			325
25  Reliance on Information Provided by the Registrar			331
25.1  Introduction			331
25.2  Property Agreements, Mineral Tenure, Surface Rights and Royalties			331
25.3  Environmental, Permitting, Closure, and Social and Community Impact			331
25.4  Taxation			332
25.5  Markets			332
Appendix A – Claims List			333

List of Tables

Table 1-1:		Grassy Mountain Mineral Resource Estimate Inclusive of Mineral Reserves – Effective date: February 28, 2026			10
Table 1-2:		Cut-off Grade Input Parameters for Gold Metal			11
Table 1-3:		Gold and Silver Mineral Reserve Estimates			12
Table 1-4:		Initial Capital Cost Estimate Summary (direct and indirect)			21
Table 1-5:		Summary of forecast project economics			22
Table 2-1:		Abbreviations and Acronyms			28
Table 2-2:		Units of Measurement			31
Table 7-1:		Grassy Mountain Claim Block Drilling Summary			62
Table 7-2:		Paramount 2016–2019 RC Pre-Collar vs. Core Lengths			70
Table 8-1:		Grassy Mountain Certified Reference Materials for 2011–2012			81
Table 8-2:		Grassy Mountain Certified Reference Materials Employed by Paramount, 2016–2019			82
Table 10-1:		Metallurgical Testwork Summary			106
Table 10-2:		2018 PFS Testwork Scope			109
Table 10-3:		Metallurgical Test Matrix for SGS Program 15944-002			109
Table 10-4:		FS Production Composites Sample Composition			110
Table 10-5:		Head Assays			110
Table 10-6:		Hazen 1990 Comminution Results			111
Table 10-7:		Summary of JK DWT Results			111
Table 10-8:		Bond Rod Mill Grindability Test Results			112
Table 10-9:		Ball Mill Work Indices			112

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Table 10-10:		Average Cyanide and Lime Consumption			117
Table 10-11:		Cyanide Destruction Test Results from Historical Work			118
Table 10-12:		Cyanide Destruction Test Results – Continuous Test			118
Table 10-13:		Leach Test Data Used for Recovery Estimation			121
Table 10-14:		Estimated Additional Plant Losses for Gold			125
Table 10-15:		Estimated Additional Plant Losses for Silver			126
Table 11-1:		Hazen Research, Inc. tonnage Factors			130
Table 11-2:		Combined Atlas and Paramount tonnage Factors			131
Table 11-3:		Approximate Grade Ranges of Gold and Silver Domains			132
Table 11-4:		Grassy Mountain Gold and Silver Assay Caps by Domain			137
Table 11-5:		Descriptive Statistics of Grassy Mountain Coded Gold Assays			137
Table 11-6:		Descriptive Statistics of Grassy Mountain Coded Silver Assays			138
Table 11-7:		Descriptive Statistics of Grassy Mountain Gold Composites			138
Table 11-8:		Descriptive Statistics of Grassy Mountain Silver Composites			138
Table 11-9:		Estimation Parameters			140
Table 11-10:		Pit Optimization Parameters			142
Table 11-11:		Parameters Used to Determine Cut-Off Grade for Mineral Resources Potentially Amenable to Underground Mining Methods			143
Table 11-12:		Grassy Mountain Gold and Silver Resources – Exclusive of Mineral Reserves			144
Table 11-13:		Grassy Mountain Gold and Silver Resources – Inclusive of Mineral Reserves			145
Table 11-14:		Resource Classification Parameters			151
Table 12-1:		Mineral Reserves Statement			154
Table 12-2:		Cut-off Grade Input Parameters for Gold Metal			155
Table 12-3:		Total Mineral Reserves Multiplied by the Metal Price			156
Table 12-4:		Stope Optimization Parameters			157
Table 12-5:		Reserve Classification Parameters			160
Table 13-1:		Rock Quality Categories			170
Table 13-2:		Rock Quality Categories			172
Table 13-3:		Summary of RMR (Bieniawski, 1976) Values by Area			173
Table 13-4:		Intact Rock Strength for Geotechnical Units Calculated from PLTs			175
Table 13-5:		Summary of RQD, RMR76, and GSI 2013 Values by Geotechnical Unit			177
Table 13-6:		Strength Parameters for Geotechnical Units			177
Table 13-7:		Iso-Probability Contours for Stable Cases Results			180
Table 13-8:		Iso-Probability Contours for Failure Cases Results			181
Table 13-9:		Reinforcement and Support Design for Mine Development Under Rock Mass Environment			189
Table 13-10:		Reinforcement and Support Design for Mine Development Under Backfill Environment			189
Table 13-11:		Mine Design Parameters			192
Table 13-12:		Mining Mobile Equipment List			195
Table 13-13:		Drilling First Principles Assumptions			196
Table 13-14:		Bolting First Principles Assumptions			197

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Table 13-15:		Shotcrete First Principals Assumptions			198
Table 13-16:		Blasting First Principles Assumptions			200
Table 13-17:		Haulage First Principles Assumptions			202
Table 13-18:		CRF Mix Recipe for UCS Testing			204
Table 13-19:		Calendars by Crew			208
Table 13-20:		Production Rates			208
Table 13-21:		Production Limits on Production Fields			208
Table 13-22:		Estimated Underground LOM Water Requirement			212
Table 13-23:		Mine Production Summary			217
Table 13-24:		Material to the Mill			218
Table 13-25:		Development Schedule			220
Table 14-1:		Process Design Criteria			241
Table 15-1:		Stage Capacity Relationship			249
Table 15-2:		Annual Average Water Balance			250
Table 15-3:		Built Infrastructure Requirements			252
Table 16-1:		Estimated Payability and Refining Costs			253
Table 16-2:		Gold Price Average (LBMA PM), $/oz			253
Table 16-3:		Silver Price Average (LBMA PM), $/oz			253
Table 16-4:		Mid-term gold price estimate by year from various organizations			255
Table 17-1:		Surface Disturbance for the Proposed Project			256
Table 17-2:		Permitting			268
Table 18-1:		Capital Cost Estimate Input Areas			270
Table 18-2:		Initial Capital Cost Estimate Summary (direct and indirect)			270
Table 18-3:		Initial Capital Cost Estimate by Major Discipline			271
Table 18-4:		Sustaining Capital Cost Estimate Summary (direct and indirect)			273
Table 18-5:		Exchange Rates used in the FS			273
Table 18-6:		Underground Capital Costs			275
Table 18-7:		Underground Leasing Costs			275
Table 18-8:		Initial Mining Capital Cost Estimate Summary			280
Table 18-9:		Initial Capital Cost Estimate Summary for Process and Site Infrastructure Areas			272
Table 18-10:		Initial TSF Capital Cost Estimate Summary			284
Table 18-11:		Initial Capital Cost Estimate Summary for Indirects			284
Table 18-12:		Initial Owner’s Cost Estimate Summary			284
Table 18-13:		Summary of operating costs over LOM			286
Table 18-14:		Summary of Underground Mining Costs per ton			286
Table 18-15:		Underground Labor Summary			287
Table 18-16:		Average Annual Process Operating Cost			289
Table 18-17:		Process Plant Labor			290
Table 18-18:		Annual Average G&A Operating Cost Summary			291
Table 19-1:		Summary of Forecast Project Economics			296

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Table 19-2:		Project Cashflow on an Annualized Basis			296
Table 19-3:		Summary Pre-Tax Sensitivity Analysis			299
Table 19-4:		Summary Post-Tax Sensitivity Analysis			300
Table 23-1:		Phase 1 Recommended Work Program			318
Table 23-2:		Recommended Work Program for Mineral Resource Estimate			319
Table 23-3:		Recommended Work Program for Mining Methods			320
Table 23-4:		Recommended Geotechnical Program			322

List of Figures

Figure 1-1:		Proposed Mine Production Schedule (tons by period)			14
Figure 1-2:		Simplified Overall Flowsheet			16
Figure 1-3:		Proposed Plant Site Layout			17
Figure 2-1:		Project Location Plan			25
Figure 3-1:		Location of the Grassy Mountain Project			34
Figure 3-2:		Grassy Mountain Claim Group			36
Figure 3-3:		Sherry and Yates Area of Interest			37
Figure 4-1:		Access to Grassy Mountain Claims Group			40
Figure 4-2:		Photograph of Grassy Mountain Area Looking			41
Figure 4-3:		Proposed Power Source for the Planned Operation			43
Figure 5-1:		Outlying Target Area Map			46
Figure 5-2:		Map of 2012 CSMAT Lines			49
Figure 5-3:		CSAMT Inversion: Resistivity at 328 to 656 Feet Below Surface			50
Figure 6-1:		Grassy Mountain Regional Geology			52
Figure 6-2:		Stratigraphic Column for the Grassy Mountain Area			53
Figure 6-3:		Grassy Mountain Deposit Area Geologic Map			55
Figure 6-4:		Conceptual Hot-Springs Epithermal Deposit Model			59
Figure 7-1:		2018 Aerial Magnetic Survey of Grassy Mountain Area			61
Figure 7-2:		Locations of Drill Holes Within the Grassy Mountain Claims Group			63
Figure 7-3:		Locations of Holes Drilled in the Grassy Mountain Deposit Area			65
Figure 7-4:		Gold Grade vs. RQD			73
Figure 7-5:		Gold Grade vs. Core Recovery			74
Figure 8-1:		Cone Analyses of Preparation Duplicates Relative to Original Chemex Gold Assays			83
Figure 8-2:		Hunter Analyses of Preparation Duplicates Relative to Original Chemex Gold Assays			84
Figure 8-3:		Chemex Analyses of RC Field Duplicates Relative to Original Chemex Gold Assays			85
Figure 8-4:		Shasta Check Analyses Relative to Original Chemex Gold Assays			86
Figure 8-5:		RMGC Check Analyses Relative to Original RMGC Gold Assays			87
Figure 8-6:		RMGC Core Duplicate “B” Relative to RMGC “A” Gold Assays			88

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Figure 8-7:		AAL Preparation Duplicate Analyses Relative to AAL Original Gold Assays			89
Figure 8-8:		Chart of ALS Analyses of CRM CDN-GS-3J			91
Figure 8-9:		Chart of ALS Analyses of Coarse Blanks – Calico			92
Figure 8-10:		AAL Pulp Checks of ALS Original Gold Analyses			94
Figure 8-11:		Chart of ALS Analyses of Coarse Blanks – Paramount			95
Figure 8-12:		ALS Gold Analyses Preparation Duplicates – Paramount			96
Figure 8-13:		Core Duplicates Relative to Original Gold Assays – Paramount			97
Figure 8-14:		Second Set of Paramount Core Duplicates Relative to Original Gold Assays			98
Figure 8-15:		Paramount RC Duplicates Relative to Original Gold Analyses			99
Figure 10-1:		Gold Leach Extraction Rate			114
Figure 10-2:		Gold Leach Extraction Rate for Grade Variability Samples			115
Figure 10-3:		Silver Leach Extraction Rate for Grade Variability Samples			116
Figure 10-4:		Drill Hole and Interval Locations for Samples in the SGS 2018 and 2020 and McClelland Programs			119
Figure 10-5:		Relationship Between Leach Feed and Residue Grades for Gold			123
Figure 10-6:		Relationship Between Leach Feed and Residue Grades for Silver			123
Figure 10-7:		Predicted versus Measured Recovery for Gold			124
Figure 10-8:		Predicted versus Measured Recovery for Silver			125
Figure 11-1:		Cross-section 3050 Showing Geology and Gold Domains			133
Figure 11-2:		Cross-section 3050 Showing Geology and Silver Domains			134
Figure 11-3:		Cross-section 3250 Showing Geology and Gold Domains			135
Figure 11-4:		Cross-section 3250 Showing Geology and Silver Domains			136
Figure 11-5:		Cross-section 3050 Showing Block-Model Gold Grades			146
Figure 11-6:		Cross-section 3050 Showing Block-Model Silver Grades			147
Figure 11-7:		Cross-section 3250 Showing Block-Model Gold Grades			148
Figure 11-8:		Cross-section 3250 Showing Block-Model Silver Grades			149
Figure 12-1:		Monthly Average Gold Price, $/oz			155
Figure 12-2:		Mine Production Design of Level 3210, Plan View			158
Figure 12-3:		Ore and Waste Designation			160
Figure 13-1:		Grassy Mountain Mine Cross-section Looking North			161
Figure 13-2:		Proposed Grassy Mountain Mine Plan (plan view)			162
Figure 13-3:		Drift Profiles			163
Figure 13-4:		Production Drift Layout (Section Looking East)			164
Figure 13-5:		Detailed level Sequence for a Typical Level			165
Figure 13-6:		Mining Lifts			166
Figure 13-7:		Golder Rock Mass Rating (all 2016–2017 core)			170
Figure 13-8:		RMR 76 Histogram from 27 Drill Holes			171
Figure 13-9:		Examples of Three Geotechnical Rock Classes			173
Figure 13-10:		GM19-37 Core Trays (89.5 to 105.5 ft.) – High Variability in Geotechnical Conditions			174
Figure 13-11:		Iso-Probability Contours for Stable Cases			180

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page xvi May 27, 2026

Figure 13-12:		Iso-probability contours for failure cases (Mawdesley, 2001)			181
Figure 13-13:		Modeling Results for Decline Ramp; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements			183
Figure 13-14:		Modeling Results for Topcut A; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements			184
Figure 13-15:		Modeling Results for Undercut B; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements			185
Figure 13-16:		Modeling Results for Undercut C; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements			186
Figure 13-17:		Three-Dimensional Model of Finite Difference			187
Figure 13-18:		Level Access Layout (Looking North)			193
Figure 13-19:		Station Design			194
Figure 13-20:		Sandvik DD422i			196
Figure 13-21:		GetMan Proshot Concrete Sprayer			197
Figure 13-22:		GetMan ProMix 6			198
Figure 13-23:		3360 Shotcrete Thickness (units in inches)			199
Figure 13-24:		Sandvik LH307 Underground Loader			201
Figure 13-25:		Sandvik TH320 trucks			201
Figure 13-26:		Waste Haulage by Year			203
Figure 13-27:		Mixing, Casting and Curing Process			205
Figure 13-28:		UCS Results vs Curing Time			206
Figure 13-29:		Simem WB100 Backfill Plant			207
Figure 13-30:		Ventilation Network (isometric view looking west)			209
Figure 13-31:		Ventilation Network (Section View Looking Northwest)			210
Figure 13-32:		Surface Ventilation Fan (Section View)			210
Figure 13-33:		Design of Vent Raises			211
Figure 13-34:		Mine Load Center (1000 kVA)			213
Figure 13-35:		Mobile Refuge Station			214
Figure 13-36:		Proposed Mine Production Schedule (tons by period)			218
Figure 13-37:		Mine Production Schedule (ounces by period)			218
Figure 14-1:		Simplified Overall Flowsheet			222
Figure 14-2:		Proposed Plant Site Layout			223
Figure 14-3:		Projected Daily Plant Water Balance, at average LOM throughput			232
Figure 15-1:		Proposed Infrastructure Layout Plan			234
Figure 15-2:		Overall TSF Layout			237
Figure 15-3:		TSF Main (North) Embankment Cross-section			241
Figure 15-4:		Site-wide Hydrologic Catchment Areas			245
Figure 15-5:		Process Plant Stormwater Contact and Non-contact Catchment Areas			247
Figure 18-1:		Proposed Mine Organizational Chart			287
Figure 19-1:		Forecast Project Post-Tax Unlevered, Undiscounted Free Cash Flow ($ M)			294
Figure 19-2:		Pre-Tax NPV & IRR Sensitivity Results			299
Figure 19-3:		Post-Tax NPV & IRR Sensitivity Results			299

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page xvii May 27, 2026

1 EXECUTIVE SUMMARY

1.1 Introduction

Ausenco Engineering Canada ULC (Ausenco), Geotechnical Mine Solutions Inc. (GMS), RESPEC Company LLC (RESPEC), SLR International Corporation (SLR) and WSP USA Inc. (WSP) compiled an updated technical report summary (the Report) on a feasibility study (the FS) completed on the Grassy Mountain Project (the Project) for Paramount Gold Nevada Corp. (Paramount), located in Oregon, USA.

This Report updates the previously filed technical report summary entitled, “Grassy Mountain Project: S-K 1300 Technical Report Summary on Feasibility Study, Oregon, United States” with an effective date of June 30, 2022. Updates include the mineral resource estimate, mineral reserve estimate, capital costs, operating costs and the economic analysis.

Paramount holds its Project interest through an indirectly wholly owned subsidiary, Calico Resources USA Corp. (Calico).

1.1.1 Terms of Reference

Measurement units used in this Report are generally U.S. customary; however, certain data, such as analytical and metallurgical testwork units may be presented in metric units. Unless otherwise stated, all monetary amounts are in United States dollars (USD).

Mineral resources and mineral reserves are reported using the definitions in subpart 229.1300 – Disclosure by Registrants Engaged in Mining Operations in Regulations (S-K 1300).

1.1.2 Effective Dates

The Report has a number of effective dates as follows:

• Mineral Resource estimates: February 28, 2026

• Mineral Reserve estimate: May 15, 2026

• Date of financial analysis that supports the Mineral Reserves: May 27, 2026.

The overall effective date of this Report is the effective date of the financial analysis, which is May 27, 2026.

Grassy Mountain Project, Property Location S - K 1300 Technical Report Summary Page 1 May 27, 2026

1.2 Property Description

The Grassy Mountain deposit is situated near the western edge of the Snake River Plain in eastern Oregon, 20 miles (mi) south of the town of Vale, Oregon and about 70 miles west of the city of Boise, Idaho. Support services for mining and other resource sector industries in the region would primarily be provided by these communities. The closest major airport is at Boise, which is a commercial airport served by all major U.S. airlines.

Access to the main Grassy Mountain deposit within the Grassy Mountain claims group is provided by Twin Springs Road, a seasonally maintained unpaved road that originates at Russell Road, a paved two-lane county road that joins with U.S. Highway 20 approximately four miles west of Vale.

1.3 Mineral Tenure, Surface Rights, Water Rights, Royalties and Agreements

The Grassy Mountain Project is located within Malheur County and is comprised of the Grassy Mountain claims group, which covers 9,300 acres. The mineral tenure holdings comprise 436 unpatented lode and mill site claims, three patented claims, and a land lease for 28 unpatented lode mining claims. Claims are held in the name of Paramount’s U.S. subsidiary, Calico.

Patented claims were individually surveyed at the time of location. Unpatented claim and fee land boundaries were established initially by handheld global positioning system (GPS) units and were formally surveyed in 2011.

Calico acquired all right, title and interest in the Project, including all existing exploration and water rights pertaining to the Grassy Mountain Project, pursuant to a “Deed and Assignment of Mining Properties” between Seabridge Gold Inc. (Seabridge Gold), Seabridge Gold Corporation (collectively Seabridge) and Calico dated February 5, 2013. Paramount acquired Calico in July 2016 and amalgamated the two companies.

Paramount’s 100% ownership of the Grassy Mountain project is subject to underlying agreements and royalties.

Seabridge Gold is entitled to a 10% net profits interest (NPI) royalty. Pursuant to the Deed of Royalties, within 30 days following the day that Calico made a production decision and construction financing was secured, Seabridge may elect to cause Calico to purchase the 10% NPI for 10 million CAD. Otherwise Seabridge will retain the 10% NPI. Seabridge, at the Report effective date, is the second largest Paramount shareholder and has indicated that it will convert its NPI into equity in Paramount, thus the Seabridge NPI has not been included in the FS.

Sherry and Yates, Inc. (Sherry and Yates) are entitled to a 1.5% royalty of the gross proceeds on any production from three patented and 37 unpatented mining claims, and a surrounding ¹⁄₂ mile area of interest. The royalty is not subject to any advance-royalty payments. The royalty covers the area of the Grassy Mountain deposit.

Cryla LLC (Cryla) leased 28 unpatented lode mining claims located west of Grassy Mountain to Calico in 2018. Calico is required to make an annual lease payment of $60,000 for the ongoing 25-year lease agreement. Calico is eligible to acquire the Property for $560,000 plus $3/oz of gold reserves, as defined by a pre-feasibility or higher confidence-level study. Cryla is entitled to a 2% net smelter return (NSR) if the gold price is ≤$1,500/oz and a 4% NSR if the gold price >$1,500/oz. Calico is entitled to reduce the NSR to 1% by paying Cryla $800,000 under any circumstances. No Mineral Resources or Mineral Reserves are estimated on the Cryla claims.

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Paramount holds three patented claims over the Grassy Mountain deposit, which provides surface rights for that area. The surrounding surface rights associated with the proposed locations of the Project surface facilities belong to the Federal government and are managed by the Vale District Bureau of Land Management (BLM) office.

Paramount holds a water right granted by the Oregon Water Resources Department to Calico. The water right was issued on April 5, 1990, through State of Oregon Water Rights Application G-11847 and Permit G-10994. Use is limited to not more than 2.0 ft³/s (897.6 gpm) measured at the well. On October 16, 2019, the State of Oregon issued a new Permit to Appropriate the Public Waters (G-18337) that replaces the previous permit and includes the requested modifications. This permit does not change the 2.0 ft³/s of water use allowed.

1.4 Accessibility, Climate, Local Resources, Infrastructure and Physiography

The climate is semi-arid and continental-interior in type. Average annual precipitation is approximately about nine inches, roughly half of which falls as snow between November and March. Mining activities are expected to be conducted year-round.

The Project area is in the semi-arid high desert plateau region of eastern Oregon. Elevations range from 3,330 to 4,300 ft above mean sea level at the main Grassy Mountain claims group area. The terrain is mainly open steppe with mesas, broad valleys, and gently rolling hills to steeper uplands.

Vegetation across the entire area consists of sagebrush, weeds, and desert grasses tolerant of semi-arid conditions.

As of the effective date of this Report, groundwater monitoring wells and unpaved access and drilling roads are the only existing infrastructure within the Grassy Mountain Project area. The infrastructure required for the proposed operation is detailed in Section 15.

The nearest community to the Project is Vale, which has a population of approximately 1,700. Vale provides fuel, restaurants, lodging, groceries, hardware supplies, and equipment-repair shops are available in Vale. Other logistical support is available in the nearby communities of Nyssa and Ontario, both of which are located within 30 mi of the Project. The metropolitan area of Boise, Idaho, is approximately a 90-minute drive from the Project site. Mining personnel, equipment suppliers, engineering expertise, and telecommunications services are all expected to be readily available within the region.

1.5 History

Companies and individuals involved in exploration prior to Paramount’s Project interest include prospectors Richard “Dick” Sherry and Eugene “Skip” Yates (Sherry and Yates), Atlas Precious Metals (Atlas), Golden Predator Mines U.S. Inc., Newmont Exploration Ltd (Newmont), Tombstone Exploration Company Ltd. (Tombstone), Seabridge Gold, and Calico BC. Work completed included reconnaissance, geological mapping, geochemical sampling (soil, float, rock chip), geophysical surveys [airborne magnetic and radiometric, ground-based gravity, gradient array (IP/resistivity) controlled-source audio-frequency magnetotelluric (CSAMT)], core and reverse circulation (RC) drilling, and Mineral Resource estimation. This work defined the Grassy Mountain deposit, on which a feasibility study was completed in 1990 by Atlas assuming a combined heap leach/milling operation and open pit mining methods.

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1.6 Geological Setting, Mineralization and Deposit

The geological setting, hydrothermal alteration, styles of gold-silver mineralization, and close spatial and timing association with silica sinter deposition, indicate that Grassy Mountain is an example of the hot-springs subtype of low-sulfidation, epithermal precious-metals deposits.

The Miocene-age Lake Owyhee volcanic field is the regional host to a number of recognized epithermal hot-spring precious-metal deposits, of which the Grassy Mountain deposit is the largest. Initial large-volume peralkaline and subalkaline caldera volcanism was followed by subsidence, forming extensive grabens. These were filled by small-volume metaluminous high-silica rhyolite domes and flows, small-volume basalt flows and mafic vent complexes, and co-eval lacustrine and fluvial sediments.

The Grassy Mountain deposit extends for about 1,900 ft along a N60°E to N70°E axis, as much as 2,700 ft in a northwest–southeast direction, and as much as 1,240 ft vertically.

The deposit is hosted in units of the Miocene Grassy Mountain Formation, consisting of interbedded conglomerate, sandstone, siltstone, tuffaceous siltstone, mudstone, and several silica sinter deposits. It is situated within a zone of complex extensional block faulting and rotation, dominated by N30°W to N10°E striking normal faults (graben faults). A set of orthogonal, N70°E-striking high-angle faults of minor displacement are inferred to link the graben faults.

Silicification (silica sinter, pervasive silica flooding, and as cross-cutting chalcedonic veins, veinlets, and stockworks) is the principal hydrothermal alteration type associated with gold–silver mineralization. In some parts of the deposit, particularly within arkose and sandy conglomerate units, silicification can be accompanied by potassic alteration in the form of adularia flooding.

Mineralization is developed largely within the silicic and potassic alteration zones. Three distinct and overlapping types of gold–silver mineralization are recognized within the central core of the deposit. These are gold-bearing chalcedonic quartz ± adularia veins, disseminated mineralization in silicified siltstone and arkose, and gold and silver in bodies of clay matrix breccia. Gold mostly occurs as electrum along the vein margins or within microscopic voids Lower-grade mineralization envelopes the higher-grade core and, further from the core, extends outwards as stratiform, mineralized lenses parallel to bedding.

1.7 Exploration

Since acquiring its Project interest in 2016, Paramount has conducted an exploration review of the available Project data, helicopter-borne aeromagnetic and radiometric and CSAMT ground geophysical surveys, drilling, Mineral Resource and Mineral Reserve estimation, baseline environmental studies, and mining studies. A feasibility study was completed in 2020, with further update completed in 2022 and in 2026 (the work covered in this report).

A number of prospects were located during the exploration programs. Of these, the Crabgrass, Bluegrass, North Bluegrass, Ryegrass and Dennis’ Folly areas in the Grassy Mountain claims block were recommended for surface work with the goal of defining further exploration drill targets.

No production is known from the Project area.

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1.8 Sample Preparation, Analyses and Security

The database includes a total of 264,112 ft drilled by four historical operators (Atlas, Tombstone, Newmont, Calico BC), from 1987 through 2012, in 442 drill holes. Paramount drilled 34 holes for a total of 25,511 ft in 2016–2019 to bring the Project total to 476 holes and 289,623 ft drilled. Approximately 77% of the footage drilled was at, and adjacent to, the Grassy Mountain deposit area, although nearly 43% of the holes were drilled at outlying prospects, as well as for water wells.

The bulk of the drill holes in the Grassy Mountain deposit area was drilled using RC, accounting for 77% of the footage drilled. Holes drilled using core methods account for about 12% of the footage drilled in the deposit area, and holes drilled with RC pre-collars and core tails account for about 11%. A total of 256 of the drill holes in the Grassy Mountain deposit area support Mineral Resource estimation, including 34 Paramount drill holes and 252 historical drill holes.

During the Calico BC and Paramount drill programs, logging recorded lithological, alteration, mineralization, and structural information, including the angle of intersection of faults with the core, fault lineations, fractures, veins, and bedding. Up until Calico BC’s involvement in the Project in 2011, the Project coordinates were based on a local grid established by Atlas. All Calico and subsequent drill-hole collar surveys were collected directly in UTM coordinates. Where information is recorded, drill collars were located using total station, Trimble, survey-grade GPS, and Topcon Hiper V GPS Receivers instrumentation. Down hole surveys were performed, where recorded, using Eastman, REFLEX EZ-Track, gyroscopic, Goodrich-Humphrey surface-recording gyroscopic and Goodrich surface-recording gyroscopic instruments.

Wet RC cuttings were split using a variable or rotary wet-cone splitter positioned below the cyclone on the RC rigs. Dry cuttings were split under the cyclone with a Jones splitter. During the Calico BC and Paramount drill programs, core sample lengths generally did not exceed 5 ft and, where possible, correlated to the 5 ft drilling runs. Competent core was cut using either a hydraulic splitter or a diamond blade core saw. During the Newmont program material too fine to be sawed was carefully swept out of the core boxes for each sample interval, split into halves using a Jones splitter, and recombined with the half-core to be sent for assaying. During the Calico BC and Paramount drill programs, core that was intensely broken or very soft was split in half using a small scoop or putty knife.

Laboratories used for sample preparation and analysis include Chemex Analytical Laboratories (Chemex; Boise and Vancouver), Rocky Mountain Geochemical Corporation (RMCG; Salt Lake City); American Assay Laboratory (AAL; Reno); and ALS Minerals (ALS; Reno). All laboratories were independent. Accreditations for Chemex, RMCG and AAL at the time used are not known. ALS holds ISO 9001:2008 accreditation for quality management and ISO/IEC17025:2005 accreditation for selected analytical techniques.

Laboratories used for check analysis included Chemex, AAL, Cone Geochemical Laboratories (Cone; Denver), and Hunter Mining Laboratories (Hunter; Reno). Accreditations at the time are not known. The laboratories were independent.

Sample preparation and analytical methods included:

• Chemex: dried, crushed to minus 1/8 inch, pulverized to 95% at minus 100 mesh. Gold and silver assays using 30 g aliquots and fire assay fusion, primarily with an atomic absorption (AA) finish.

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• RMCG: dried, crushed to minus 10 mesh, pulverized to minus 48 mesh and repulverized to nominal, minus 150 mesh. Fire assayed for gold with a gravimetric and AA finishes. Screen-fire assays completed where gold values were >0.20 oz Au/ton.

• AAL: dried, crushed to 8–10 mesh, pulverized to 90% -150 mesh. Gold assays via fire assaying with an AA finish. Silver via method D210, which included aqua-regia digestion.

• ALS: dried, crushed to 75% at <6 mm, pulverized to 85% at <200 mesh (75 µm). Gold assays via fire assaying with an AA finish. A separate five-gram aliquot was used for inductively coupled plasma atomic-emission spectrometric (ICP-AES) determination of silver and 32 major, minor, and trace elements following a four-acid digestion. Gold overlimits re-assayed using fire assay with gravimetric finish. Silver overlimits re-assayed using 10-g aliquot with a four-acid digestion for silver and an AA finish or 30-g fire assay with a gravimetric finish.

The available Atlas quality assurance and quality control (QA/QC) data of consequence (the preparation and field duplicates) suggest that the original gold assay results may be overstated to some extent. However, the average grade of the duplicate dataset is much higher than the average grade of the Grassy Mountain deposit and repeat analyses of only the higher-grade portion of a deposit with free gold can yield lower results than original assays. Without further data, it is impossible to know whether there is a high bias in the Atlas results, although a comparison of resources with and without Paramount drill data suggests there are no material issues with the Atlas data. The Newmont QA/QC data do not identify any issues, while it is possible that the Tombstone gold values are slightly understated. No issues were revealed by the Paramount certified reference material (CRM), blank, and preparation-duplicate data. The core-duplicate data suggest that the Paramount gold assays of core, particularly at higher grades, may be understated to some degree. These data also serve to emphasize the importance of careful sampling and splitting of core-box fines. The variability evidenced by the duplicate data from all operators at Grassy Mountain does not exceed normal bounds, especially considering the presence of visible gold.

1.9 Data Verification

The Project drill-hole database was subjected to data verification and corrections prior to the initiation of the 2016–2017 drilling program. This verified database was periodically updated by RESPEC with information acquired during Paramount’s various drilling programs.

As part of the 2016–2017 drilling program, all prior drill-hole collars that could be identified in the field were re-surveyed. The collar locations of 82 Atlas drill holes, six Newmont drill holes, four Tombstone drill holes, and nine Calico drill holes were surveyed. RESPEC was provided the original digital file produced by the survey contractor, and RESPEC used this file to compare the new survey locations with those in the existing database. The scale of the discrepancies in the drill hole locations is not considered to be material due to the nature of the Grassy Mountain mineralization and the 10 x 10 x 10-ft block size used in modelling.

RESPEC compared the total depths of 47 historical drill holes against historical records and found no material errors.

Down-hole survey records from selected drill holes from the historical drilling were examined. No material errors were noted; errors that were identified were corrected in the database. The drill-collar azimuths and dips for 40 drill holes were checked against historical records and no discrepancies were found.

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The database assay values for selected intervals from historical drill holes were checked against historical documents. No material discrepancies were found; errors that were identified were corrected in the database.

RESPEC personnel conducted a number of site visits that included inspection of outcrop, visiting core and RC drill sites with ongoing sampling and logging, review of numerous mineralized intervals in drill core, review of all Project procedures related to logging, sampling, and data capture, and on-site evaluation of several target areas throughout the Project area.

The RESPEC QPs verified that the Grassy Mountain Project data are acceptable as used in this Report, most significantly to support the estimation and classification of the Mineral Resources and Reserves.

1.10 Mineral Processing and Metallurgical Testwork

In support of the FS, historical work conducted by Hazen Research Inc., Golden Sunlight, Newmont and Resource Development Inc. (RDI) was reviewed. The degree to which historical metallurgical samples are representative of the Grassy Mountain deposit is not known with certainty, but there is no evidence that the historical samples were not representative. Early historical work listed above is viewed as indicative or informative only since the qualified person (QP) was not able to reconcile the test results to drill hole locations and depth to confirm that these drill holes represent the ore in the current mine plan.

In the 2018 PFS metallurgical testing program, Paramount completed head grade analyses, comminution tests (JK drop-weight tests), gravity and leach tests, and rheology and solid/liquid separation tests on CIL tailings samples. This was supplemented in 2019 and 2020 FS metallurgical testing programs with chemical and mineralogical analysis, Bond ball and rod mill work index tests, and testwork on leaching, oxygen demand, and cyanide destruction testing.

Tests were performed on mineralization that is considered to be representative of the material that will be sent to the plant. Composite samples representing major lithologies, Year 1 and Year 2 production composites and a range of head grades aligned with the minimum and maximum values expected in the plant feed in the initial two years of production were tested in the 2019 and 2020 FS metallurgical testing programs.

The grade variability composite samples calculated gold and silver grades ranged from 0.104–0.383 oz/ton Au (3.57–13.13 g/t Au) and 0.149–0.628 oz/ton Ag (5.1–21.5 g/t Ag).

Comminution testing showed that all the samples tested are considered hard to very hard, with Bond ball mill work indices ranging from 20.8 to 32.0 kWh/ton.

Bottle roll and agitated batch leach tests showed that the samples were highly responsive to recovery by cyanidation at a grind size of 80% passing 150 mesh (106 µm) or finer, with leach recoveries ranging from 82.1–97.5% for gold and 59.0–84.6%for silver, dependent on leach feed grade.

Overall plant recoveries for gold are predicted to range from 89.5–94.9% for head grades of 0.096–0.58 oz/ton Au (3.3–17.4 g/t Au) over the life of mine (LOM). Overall plant recoveries for silver are predicted to range from 62.7–80.4% for head grades of 0.161–0.523 oz/ton Ag (5.5–17.9 g/t Ag) over the LOM.

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Cyanide destruction tests achieved <0.2 mg/L CN_WAD, which is well within the maximum legislated value in Oregon of 30 mg/L.

Mercury grades were in the range of 0.054–0.077 oz/ton (1.86–2.64 g/t) in the leach feed, and the concentration of mercury in solution after leaching ranged from 0.08–0.26 mg/L. A retort and gas collection and scrubbing system was incorporated into the plant design to manage and control mercury in the process. Arsenic is present in the feed at concentrations ranging between 3.47–5.34 oz/ton (119–183 g/t) and is not expected to be problematic in processing. No other elements that may cause issues in the process plant or concerns with product marketability were noted.

1.11 Mineral Resource Estimate

Paramount supplied RESPEC with a set of detailed cross-sectional lithological and structural interpretations that covers most of the extent of the Grassy Mountain deposit. These cross-sections served as the base for RESPEC’s modeling of the gold and silver mineralization. During that process, RESPEC added some additional structures and made other minor modifications to Paramount’s structural interpretations.

The density values RESPEC used in the estimation were based on water-displacement method measurements performed by Atlas and Paramount. The density associated with the Grassy Mountain mineralization is consistent, and unmineralized rocks are distinctly less dense – likely a reflection of the strong silicification associated with all grades of mineralization compared to weak or absent silicification in unmineralized rocks. RESPEC used tonnage factors of 13.5 ft³/ton for mineralized material and 14.8 ft³/ton for non-mineralized material.

The Grassy Mountain gold-silver deposit is hosted by arkoses, siltstones, mudstones, and sinters of the Grassy Mountain Formation. From the assay data, RESPEC identified three gold-grade populations and three silver grade populations. The high-grade domains are comprised of a central core zone characterized by gold grades greater than 0.03 oz/ton Au and silver grades over 0.15 oz/ton Ag. Sub-vertical structures and sub-horizontal stratigraphy control the high-grade central core mineralization and domains within a broad envelope of primarily stratigraphically controlled low-grade mineralization. The highest-grade gold (>~0.25 oz Au/ton) and silver (>~0.4 oz/ton Ag) population strongly correlates with the presence of thin, often banded, quartz–chalcedony veins and veinlets and/or breccias. However, the highest-grade mineralization does not have sufficient continuity for confident domain modeling. Therefore, RESPEC did not explicitly model it.

RESPEC determined assay caps by inspecting distribution plots of the coded assays by domain and identifying high-grade outliers appropriate for capping, then capped gold at values ranging from 0.09–10 oz/ton Au and silver at values ranging from 0.12–7 oz/ton Ag.

RESPEC used level-plan gold and silver mineral-domain polygons to code volume partial percentages into a three-dimensional block model with a model bearing of 340° that consisted of 5-ft x 10-ft x 10-ft blocks (model x, y, z). RESPEC also coded the block model using a digital topographic surface.

RESPEC coded two estimation areas into the block model. In one, the stratigraphically-controlled mineralization dips shallowly at about -15° and encompasses most of the in the Grassy Mountain deposit. The second estimation area is located in the west–southwestern portion of the deposit where the dips of the stratigraphic units steepen to approximately -20°.

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Using length-weighted composites, RESPEC completed the grade interpolation in three passes in two estimation areas. In the outer estimation area, low-grade gold and silver domains, as well as areas outside modeled domains, were entirely estimated using search ellipses that reflect stratigraphic orientations. The high-grade gold and silver domains in estimation area two exhibit both sub-horizontal (stratigraphic) and high-angle (structural) controls. The first pass in the high-grade domain reflects high-angle structural controls. The second estimation pass applied a search ellipse reflective of stratigraphic control but did not overwrite grades estimated during pass 1. The third and final estimation pass was an isotropic pass that RESPEC used to estimate grades into blocks that had not been estimated by the first two passes.

The gold and silver high-grade domains captured multiple populations, which mandated restrictions on the search distances. The multiple populations lack sufficient continuity to be explicitly modeled as separate domains. RESPEC also used search restrictions because initial estimation runs without the restrictions resulted in unrealistic volumes and distribution of estimated high grades in the block model.

RESPEC interpolated gold and silver grades using inverse-distance to the third power (ID3), ordinary-kriging (OK), and nearest-neighbor (NN) methods and chose to report the estimate of mineral resources using the ID3 interpolations because the ID3 results more closely represented the geology and distribution of drill-hole assay data than those obtained by OK. RESPEC performed estimation passes independently for each mineral domain and coupled the estimated grades with the partial percentages of the mineral domains and the outside-domain volumes to enable the calculation of weight-averaged gold and silver grades for each block. Therefore, this methodology fully block-dilutes the final resource grades and their associated resource tonnages.

The Grassy Mountain deposit has the potential to be mined by open-pit methods. While Grassy Mountain’s mineral reserves are estimated on the basis of a proposed underground-mining scenario, the mineral reserves represent only a small subset of the entire gold-silver deposit. The deposit’s mineral resources are reported to reflect potential open-pit extraction and milling as the primary scenario, with a secondary scenario of potential underground mining of a very small quantity of material lying outside of the lower portions of the open pit.

RESPEC used a conceptual pit shell to constrain the Grassy Mountain deposit’s mineral resources, with the added constraint of a gold equivalent (AuEq) cut-off grade of 0.008 oz/ton AuEq applied to all model blocks lying within the optimized pit and calculated the oz/ton AuEq grade of each model block as follows:

oz/ton AuEq = oz/ton Au + (oz/ton Ag ÷ 129).

The factor of 129 reflects metal prices of $3,100/oz gold and $34/oz silver, as well as recoveries of 80% for gold and 60% for silver.

RESEPC estimated mineral resources potentially amenable to underground mining methods by applying a cut-off of 0.070 oz/ton AuEq to blocks lying immediately outside the optimized pit.

Both resource estimates are based on a 5,000 tons/day processing rate, with processing assumed to consist of crushing and milling followed by carbon-in-leach recovery.

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1.12 Mineral Resource Statement

Mineral resources are reported to be inclusive of the mineral resources that have been converted to mineral reserves, using the mineral resource definitions set out in S-K 1300. Mineral resources that are not mineral reserves do not have demonstrated economic viability. RESPEC is the qualified person firm responsible for the mineral resource estimate. The mineral resource estimates are presented in Table 1-1.

Table 1-1: Grassy Mountain Mineral Resource Estimate Inclusive of Mineral Reserves – Effective date: February 28, 2026

		Amount (tons)		Grade/qualities (oz/ton Au)		Grade/qualities (oz/ton Ag)		Cut-off grades (oz/ ton Au)		Metallurgical Recovery
Measured Mineral Resource		33,999,000		0.016		0.063		Inside pit: 0.008		Au – 80%
Indicated Mineral Resource		23,795,000		0.034		0.098		Outside pit: 0.070		Ag—60%
Measured + Indicated Mineral Resource		57,794,000		0.023		0.077		Inside pit: 0.008		Au – 80%
Inferred Mineral Resource		3,779,000		0.019		0.056		Outside pit: 0.070		Au – 80% Ag—60%

Notes:

• RESEPEC is the qualified person firm responsible for the mineral resources estimate.

• Mineral resources are comprised of all model blocks at a 0.008 oz/ton AuEq cut-off that lie within an optimized pit plus blocks at a 0.070 oz/ton AuEq cut-off that lie outside the optimized pit.

• oz/ton AuEq (gold equivalent grade) = oz/ton Au + (oz/ton Ag ÷ 129).

• Mineral resources summarized in the table immediately above are reported inclusive of the mineral resources converted to mineral reserves. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

• Mineral resources potentially amenable to open pit mining methods are reported using a gold price of $3,100/oz, a silver price of $34/oz, a throughput rate of 5,000 tons/day, assumed metallurgical recoveries of 80% for Au and 60% for Ag, mining costs of $3.14/ton mined, processing costs of $16.33/ton processed, general and administrative costs of $2.79/ton processed, and refining costs of $5.00/oz Au and $0.50/oz Ag produced. Mineral resources potentially amenable to underground mining methods are reported using a gold price of $3,100/oz, a silver price of $34/oz, a throughput rate of 5,000 tons/day, assumed metallurgical recoveries of 92.8% gold equivalent, mining costs of $141.77/ton mined, processing costs of $39.09/ton processed, general and administrative costs of $20.15/ton processed, and refining costs of $5.00/oz gold equivalent produced.

• The effective date of the mineral resources estimate is February 28, 2026, and the effective date of the database on which the Mineral Resources estimate is based is May 1, 2018.

• Rounding may result in apparent discrepancies between tons, grade, and contained metal content.

Inclusive of mineral reserves, the mineral resources contain 540,000 oz of gold and 2,142,000 oz of silver classified as measured, 817,000 oz of gold and 2,325,000 oz of silver classified as indicated, and 73,000 oz of gold and 210,000 oz of silver classified as inferred. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

1.13 Mineral Reserve Estimate

An underground mining scenario is assumed using mechanized cut-and-fill methods, which, following ramp-up, will produce 1,200–1,400 tons/day, four days a week. This mining rate will provide sufficient material for the 750 ton/day mill and processing plant to operate at full capacity for seven days a week.

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The Proven and Probable reserves for Grassy Mountain have been estimated by first calculating an economic NSR cut-off for mining underground stopes, then using the NSR cut-off to design stope shapes centered on Measured and Indicated Mineral Resource blocks with the mining revenue greater than or equal to the NSR cut-off. All Inferred material was considered to be waste with no value or metal content. Internal and external dilution and mining recoveries (ore loss) were estimated and applied as modifying factors based on the total tonnage of material inside of the final designs.

The economic cut-off grade used for stope design is based on initial economic parameters shown in table below.

Table 1-2: Cut-off Grade Input Parameters for Gold Metal

Name		Quantity		Unit
UG Mining costs		141.18		$/ton processed
Surface Rehandle		0.22		$/ton processed
Process Costs		39.09		$/ton processed
General and administrative (G&A) Costs		20.15		$/ton processed
Total Operating Costs		200.64		$/ton processed
Refining Cost		6.00		$/oz processed
NSR Royalty		1.5%		percent
Gold Metal Recovery		92.8%		percent
Gold Selling Price		2,750		$/oz Au
Calculated Cutoff Grade		0.080		oz Au/ton
Mineral Reserve Cutoff Grade Used		0.080		oz Au/ton
NSR Economic Cutoff		201.00		$/ton processed

The calculated gold cut-off grade is 0.08 oz/ton Au. The economic stope NSR cutoff was used in the stope optimization to identify the Measured and Indicated blocks available for consideration to be converted to Mineral Reserves. Measured and Indicated resource blocks with NSR value less than the economic stope NSR cut-off, as well as all Inferred resource blocks irrespective of grade, were considered as waste and applied to internal dilution.

Each stope block was queried against the resource block model to determine the tonnages and grades within the stope shapes. Stopes with an average measured or indicated gold grade equal to and above the economic NSR cut-off were selected to be included in the mine plan and Mineral Reserves estimate. Some isolated stopes above the cut-off grade threshold were eliminated from consideration because the development to extract them would cost more than the economic return. Dilution and recovery were not considered during the stope optimization. The dilution and recovery were applied as modifying factors later in the process.

A modifying factor of 8% was used for calculating external dilution tons. All Inferred resource blocks or partial blocks within the stopes and all unclassified material within the stopes is considered internal dilution. The tons were accounted for with zero grade.

Mining recovery is estimated to be 97% based on an assumed ore loss of 3%. This is considered appropriate for the highly selective mechanized cut-and-fill mining method selected for the Grassy Mountain deposit and it is based on similar operations in disseminated ore bodies.

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1.14 Mineral Reserve Statement

The reference point for the estimated Mineral Reserves is the crusher. The Mineral Reserves estimated for the Grassy Mountain Project are provided in Table 1-3 and have an effective date of May 15, 2026. The Qualified Person firm for the Mineral Reserve estimate is RESPEC.

Table 1-3: Gold and Silver Mineral Reserve Estimates

(US Imperial units)
		tons (‘000s)				Grade (oz/ton Au)				Gold (‘000 oz)				Grade (oz/ton Ag)				Silver (‘000 oz)
Proven mineral reserves			299				0.167				50				0.256				77
Probable mineral reserves			1,908				0.186				355				0.287				548
Total Proven and Probable reserves			2,207				0.184				405				0.283				625

Notes:

• Mineral reserves have an effective date of May 15, 2026.

• Mineral Reserves are reported inside stope designs assuming drift-and-fill mining methods, and an economic net smelter return cutoff grade of $200.64 per ore ton processed. The economic cut-off grade estimate uses a gold price of $2,750/oz, mining costs of $141.18/ton processed, surface re-handle costs of $0.22/ton processed, process costs of $39.09/ton processed, general and administrative costs of $20.15/ton processed, and refining costs of $6/oz Au recovered.

• Metallurgical recovery utilizes the leach recovery schedule discussed in section 10 of the Technical Report Summary

• Mineralization that was either not classified or was assigned to Inferred Mineral Resources was set to waste.

• A 1.5% NSR royalty is payable.

• Rounding may result in apparent discrepancies between tons, grade and contained metal content.

1.15 Mining Methods

1.15.1 Overview

The Grassy Mountain mine will be an underground operation accessed via one decline and a system of internal ramps. One set of stacked ventilation raises is included in the design to be used for ventilation and secondary egress. The underhand mechanized cut-and fill mining method was selected. Cemented rock fill (CRF) will be used for backfill. The underhand mechanized cut-and-fill method is highly flexible and can achieve high recovery rates in deposits with complex geometries, as is the case at the Grassy Mountain deposit. The estimated mine life is 9.3 years.

The mining sequence contains a detailed level sequence and an underhand sequence. The level access is mined first. The mains are mined second. Typically, two mains are mined at the same time providing multiple mining locations on a level. After the mains are mined, then the production drifts can begin mining. The production drifts are sequenced with primaries and secondaries. The primaries are mined and backfilled first. This continues until the entire level is complete. After the entire level is complete the level access is backfilled. The underhand sequence is grouped into lifts. One level in each lift can be mining at any given time during the life-of-mine. The underhand sequence starts at the top and works down in elevation. Constraints are applied to ensure that the bottom level of a lift does not influence the top level of the lift below.

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1.15.2 Mine Design

The portal is designed to allow access to the underground mine facilities while providing adequate space for equipment and vehicles. It will be located uphill and south of the primary crusher. Weak rock mass ground conditions at the portal require that a shallow box-cut excavation be established to form a suitable face where tunneling can occur.

The Grassy Mountain orebody will be accessed using a 15ft x 15 ft main decline, developed from a portal on surface. The decline will provide a connection to all services. The design intent is to have the decline located as close as possible to the mineralization to reduce transportation costs but sufficiently removed from mining activities to ensure that the decline is geotechnically stable for the planned LOM.

Level stations will have a standoff distance from the orebody of approximately 300 ft. This distance is determined by the maximum gradient of the level access of 12.5%, the geometry of accessing five levels for every one level station, and the geometry of the orebody. There are five stations planned for the mine, accessed off the decline, and each station will access up to five production levels. Each station will have a truck loading bay (used to load trucks with load–haul–dump (LHD) vehicles), power bay (used to store the mobile load center), ventilation access (will connect on each station via vent raises), stockpile (used to store material until it can be loaded into trucks), sump (used to collect mine water, and level access (provide access to the production stopes).

When a production stope gets within two rounds of the design, the stope will go on grade control. When a stope is on grade control, every round must be sampled before the next round can be drilled. The stope may end prematurely or extend past the design if the assayed grade is below or above the cut-off grade.

The ventilation network was designed to comply with U.S. ventilation standards for underground mines. The planned ventilation will use a push/pull system and will require a exhaust fan on the surface. A raise bore will be used to construct ventilation raises between level stations and connecting to the surface fan. Each vent raise will have a diameter of 12 ft. Each raise will be steel lined and have an escape ladder. Auxiliary fans will take air from the main circuit and push the air to the working face on the level using vent ducting and vent bag. Each level will have an auxiliary fan at the level station.

Mine operations will be based on the usage of mobile mining equipment suitable for underground mines. The estimate of the fleet size was based on first principles and equipment running-time requirements to achieve the mine production plan. Equipment is conventional for mechanized cut-and-fill mining operations.

Water will be needed for underground production drilling, bolting, shotcrete, and diamond drilling. The required LOM water supply has been estimated based on the mine-equipment requirements.

Underground power will be provided by two transformers. The transformers will be moved, as required, depending on the location of the mining activities. A main power line will be installed along the rib of the decline. Line power will also be extended to the locations of the ventilation raise to supply power to the ventilation fans.

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Two mobile emergency refuge stations will be provided in case of fire or rockfalls that would block access and prevent full evacuation of personnel.

1.15.3 Mine Production Plan

The proposed production plan is shown in Figure 1-1.

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1.16 Processing and Recovery Methods

The process plant will be designed with conventional processing unit operations frequently used within the gold processing industry. The process plant will treat 750 tons per day and will operate with two 12-h shifts per day, 365 days per year, producing gold doré bars. The major equipment within the process plant is specified in accordance with the climate, site conditions, ore grades and metallurgical performance outlined in this report. Any deleterious metals present in the ore such as mercury will be abated by specialized equipment installed in the process plant and are not expected to impact payability terms. The plant will have average head grades of 0.177 oz/ton Au and 0.277 oz/ton Ag.

The plant feed will be trucked from the underground mine to a modular crushing facility that will include a jaw crusher as the primary stage and a cone crusher for secondary size reduction. The crushed ore will be ground by a ball mill in closed circuit with a hydrocyclone cluster. The hydrocyclone overflow with P80 of 150 mesh (106 µm) will flow to a hybrid leach/carbon-in-leach (CIL) recovery circuit via a pre-aeration tank. Gold and silver leached in the CIL circuit will be recovered onto activated carbon and eluted in a pressurized Zadra-style elution circuit and then recovered by electrowinning in the gold room. The gold–silver sludge will be dried in a mercury retort oven and then mixed with fluxes and smelted in a furnace to pour doré bars. Mercury is condensed in the retort and collected for off-site disposal. Carbon will be re-activated in a carbon regeneration kiln before being returned to the CIL circuit. CIL tailings will be treated for cyanide destruction prior to pumping to the tailings storage facility (TSF) for disposal.

The installed power for the process plant will be 4,445 hp and the power consumption is estimated to be 72 kWh/ton processed. Raw water will be pumped from borehole wells to a raw-water storage tank. Potable water will be sourced from the raw water tank and treated by a potable water treatment plant. Gland water will be supplied from the raw-water tank. Process water will primarily consist of TSF reclaim water. Reagents will include lime, sodium cyanide, sodium hydroxide, copper sulfate, hydrochloric acid and sodium metabisulfite.

The simplified overall flowsheet is shown in Figure 1-2 The plant site layout is shown in Figure 1-3.

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Figure 1-2: Simplified Overall Flowsheet

Source: Ausenco, 2020

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Figure 1-3: Proposed Plant Site Layout

Source: Ausenco, 2020

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1.17 Infrastructure

1.17.1 Overview

The Project infrastructure includes a mining portal and decline, supported by an extensive network of access and haul roads connecting key facilities such as the TSF, temporary waste rock storage facility (TWRFS) and other site areas. Surface infrastructure comprises site access controls, administrative and operational buildings, and specialized processing and support facilities including a gold room, assay laboratory, reagent storage, workshops, warehouses and truck maintenance areas. Utilities and services include fuel storage and dispensing, water supply and treatment systems, water wells, a raw water tank and a 14.4 kV power line. Additional components include waste and tailings management facilities and an explosives magazine to support the underground mining operations.

1.17.2 Temporary Waste Rock Storage Facilities (TWRSF) and Borrow Pits

During operation, a lined stockpile for waste rock will be temporarily managed on the surface to be used as CRF as needed. The containment and drainage collection systems installed below the TWRSF will be the same systems used for the TSF impoundment basin.

A basalt borrow quarry will be located on the east side of the mine area where there are basalts that are believed to be suitable for construction, mine-backfill and reclamation materials. A small borrow pit north of the processing area is planned for additional construction material. Borrow material will be generated using contract mining.

Closure Cover Borrow Areas located immediately west of the basalt borrow quarry and south of the TSF will be developed as additional vegetative closure cover material for final reclamation of the surface facilities.

1.17.3 Tailings Storage Facility

The proposed TSF will cover approximately 108 acres and will be located in a broad valley immediately west of the Grassy Mountain mine portal and process facilities. The TSF will fill the valley and require embankments on the north and west sides to impound the tailings. The main embankment will cross the natural drainage on the north side of the TSF, and a secondary embankment will be constructed along the western ridge. The TSF design envisages three overall stages, Stage 1 will be split into two intermediate phases.

Based on the TSF design, the Stage 3 TSF will provide a total storage capacity of 3.64 Mtons. However, for the purposes of this Study, only approximately 2.4 Mtons are planned to be delivered to the TSF. Therefore, only Stages 1, 2, and a portion of Stage 3 are required for this Study.

The TSF is designed as a “zero discharge” facility, capable of storing runoff from tributary areas and direct precipitation on the facility resulting from the 500-year, 24-hour storm event, as well as an allowance for wave run-up due to wind action. It will be a 100% geomembrane-lined facility with a continuous, engineered lining system extending across the impoundment basin and the upstream slope of the embankments.

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A lined reclaim pond, to be located downstream (north) of the TSF, will capture all tailings draindown collected in the underdrain collection system from the tailings and TWRSF draindown. A supernatant pool will be maintained away from the embankments on the eastern side of the TSF by controlled deposition of tailings from spigots installed around the perimeter of the facility.

1.17.4 Water Management

Contact and non-contact surface water will be routed around the plant site:

• Non-contact water runoff is designed to flow into natural drainages downstream of the site to unnamed tributaries of Negro Rock Canyon which in turn discharges to the lower Malheur River.

• Meteoric water contacting the process plant site and associated infrastructure will be diverted through contact water diversion ditches and channels to a geomembrane-lined contact water pond to be located east of the process plant.

Permanent channels are designed to convey the 100-year, 24-hour storm event with nine inches of freeboard, or 500-year, 24-hour storm event without overtopping. Temporary channels were designed to convey the 25-year, 24-hour storm event with nine inches of freeboard, or 100-year, 24-hour storm event without overtopping.

1.17.5 Water Balance

Water supply from the raw water production wells and mine dewatering is projected to be sufficient to support the mine plan requirements and during seasonal fluctuations. Water demands are expected to increase and decrease seasonally and during periods of extended dry and wet climactic years, respectively. During periods of extended dry conditions, additional make-up water from the production wells may be required.

1.18 Market Studies and Contracts

The proposed Grassy Mountain operation will produce doré bars on site, which will then be shipped to an out of State refinery. There is currently no contract in place with any refinery or buyer for the doré.

No market studies have been completed. Gold and silver are freely-traded commodities. The doré that will be produced by the mine is considered to be readily marketable with no deleterious/penalty elements. Although mercury is present in the ore, a retort and recovery system has been included to maintain doré quality.

Metal pricing used in the economic analysis is based on long-term flat metal prices of $3,600/oz Au, and $48.00/oz Ag, which are based on consensus forecasts from various financial institutions.

Paramount has no current contracts for property development, mining, concentrating, smelting, refining, transportation, handling, sales and hedging, forward sales contracts or arrangements.

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1.19 Environmental, Permitting and Social Considerations

The final Environmental Impact Statement (EIS) and record of decision were issued by BLM on January 29, 2026.

Draft state permits were issued for public comment on December 8, 2025. The public comment period has concluded and final state permits are anticipated to be issued in the third quarter of 2026.

1.19.1 Environmental Considerations

Paramount is also currently working with BLM and local ranchers to develop and plan rangeland improvements in the vicinity of the mine site.

1.19.2 Permitting Considerations

Paramount is currently working with multiple tribal entities, BLM and the State Historical Preservation Office (SHPO) to finalize mine construction and operation planning to minimize impacts to identified cultural resources. Following concurrence from SHPO, the final state permits are anticipated to be issued allowing for bonding and the progression of construction.

1.19.3 Social Considerations

Paramount continues to work with local, state, federal and tribal entities as the state permitting process is completed.

1.19.4 Closure and Reclamation Considerations

The closure plan and associated Reclamation Cost Estimate (RCE) were updated in February 2026 to account for updated unit rates and direction received from BLM and Department of Geology and Mineral Industries (DOGAMI) during the permitting process. Both BLM and DOGAMI have accepted the closure plan and RCE.

1.20 Capital and Operating Cost

1.20.1 Capital Cost Estimate

The capital cost estimate is reported in Q2 2026 USD. The capital costs are at a minimum feasibility level of confidence of ±15% as is defined in S-K 1300, and are prepared using the AACE Class 3 estimate standards, with a contingency of 10%.

The estimate includes the cost to complete the design, procurement, construction and commissioning of all the identified facilities. The estimate was based on the traditional engineering, procurement and construction management (EPCM) approach where the EPCM contractor oversees the delivery of the completed project from detailed engineering and procurement to handover of a working facility. For equipment sourced in Canadian dollars (CAD), an exchange rate of 0.733 USD:CAD was assumed.

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The estimate was derived from budgetary pricing for major items in the mechanical equipment list, electrical equipment list and contractor work packages (e.g. concrete, structural steel, platework, etc.), benchmarked against similar projects and scaled/escalated accordingly. The estimates were based on a number of fundamental assumptions as indicated in process flow diagrams, general arrangements, material take offs (MTOs), cable schedules, scope definition and a work breakdown structure. The estimate included all associated infrastructure as defined by the scope of work developed in 2020 FS and carried in the 2022 FS update.

The initial capital cost estimate of $189.8 million is summarized in Table 1-4.

Table 1-4: Initial Capital Cost Estimate Summary (direct and indirect)

WBS		Description		$ M				% of Total Costs
1000		Mining			26.2			14
2000		Site development			7.2			4
3000		Mineral processing			43.4			23
4000		Tailings management & waste rock facility			13.3			7
5000		On-site infrastructure			17.3			9
6000		Off-site infrastructure			16.8			9
Direct Subtotal					124.6			66
7000		Project indirect costs			28.0			15
9000		Owner’s costs			15.6			8
Indirect Subtotal					43.6			23
8000		Provisions (Contingency)			19.8			10
N/A		Capitalized Operating cost			1.7			1
Project Total – Initial Capital					189.8			100

1.20.2 Operating Cost Estimate

The operating cost estimate has an accuracy of ±15% reported in Q2 2026 USD. The operating costs are at a minimum feasibility level of confidence of ±15% as is defined in S-K 1300.

The LOM underground mining costs are estimated at $332.9 million over the LOM, and average $141.18/ton processed over the LOM. Excluding mining costs from the pre-production period (accounted for in the initial capital cost) results in an average mining cost of $140.60/ton processed over the LOM.

The LOM process operating cost is estimated at $89.3 million over the LOM, and averages $37.72/ton processed over the LOM.

The LOM general and administrative (G&A) costs are estimated at $5.4M/a or $48.7M over the LOM, and average $20.65/ton processed over the LOM.

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1.21 Economic Analysis

1.21.1 Economic Summary

The economic analysis is based on proven and probable reserves. The capital and operating cost estimates were developed in Q2 2026 to target a level of accuracy of ±15% which aligns with an AACE International Class 3 level estimate. The capital cost estimate includes a 10% contingency on the initial capital costs.

The Project has been evaluated using a discounted cashflow (DCF) analysis. Cash inflow consists of annual revenue projections for the Project. Cash outflows such as capital costs, operating costs, taxes, and royalties are subtracted from the inflows to arrive at the annual cashflow projections.

The post-tax net present value (NPV) at a 5% discount rate (NPV_5%), is $374.7 million NPV_5% with a post-tax internal rate of return (IRR) of 38.9%, and an initial payback of 2.1 years. These economic results utilize base-case prices of $3,600/oz gold and $48.00/oz silver.

Table 1-5 below provides a summary of the forecast project economics.

Table 1-5: Summary of forecast project economics

Area		Item		Units		LOM Total/Avg.
General		Gold price		$/oz		3,600
		Silver price		$/oz		48.00
		Mine life		years		9.3
		Total mill feed tons		tons x 1,000		2,358
Production (gold)		Mill head grade Au		oz/ton		0.18
		Mill recovery rate Au		%		92.6
		Total mill ounces recovered Au		oz x 1,000		385.8
		Total average annual production Au		oz x 1,000		41.4
Production (silver)		Mill head grade Ag		oz/ton		0.28
		Mill recovery rate Ag		%		73.5
		Total mill ounces recovered Ag		oz x 1,000		480.1
		Total average annual production Ag		oz x 1,000		51.5
Operating Costs		Mining cost		$/ton processed		140.60
		Processing cost		$/ton processed		37.72
		G&A cost		$/ton processed		20.65
		Total operating costs		$/ton processed		198.96
		Refining cost Au		$/oz		5.00
		Refining cost Ag		$/oz		0.50
		*Cash costs net of by-products		$/oz Au		1,217.95
		**AISC net of by-products		$/oz Au		1,441.57

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Area		Item		Units		LOM Total/Avg.
Capital Costs		Initial capital		$M		189.8
		Sustaining capital		$M		65.1
		Closure costs		$M		21.1
Financials (pre-tax)		Gross Revenue		$M		1,410.6
		Pre-tax unlevered free cash flow		$M		658.0
		Pre-tax NPV, 5%		$M		458.9
		Pre-tax IRR		%		42.8
		Pre-tax Payback		years		2.1
Financials (post-tax)		Post-tax unlevered free cash flow		$M		540.7
		Post-tax NPV, 5%		$M		374.7
		Post-tax IRR		%		38.9
		Post-tax Payback		years		2.2

Notes:

* Cash costs consist of mining costs, processing costs, G&A and refining charges and royalties.

** All-in sustaining costs (AISC) include cash costs plus sustaining capital and closure costs. AISC is at the project level and does not include an estimate of corporate G&A.

1.21.2 Sensitivity Analysis

A sensitivity analysis was conducted on the base-case pre-tax and post-tax NPV_5% and IRR of the Project using the following variables: metal prices, discount rate, total operating costs, initial capital costs, recovery, and head grade. The analysis showed that the Project is most sensitive to metal price, head grade, metallurgical recovery rates, and initial capital cost, and less sensitive to operating cost.

1.22 Conclusions

Based on the assumptions and parameters presented in the Report, the Grassy Mountain Project has a mine plan that is technically feasible and economically viable. The positive financials of the Project ($374.7 million post-tax NPV_5% and 38.9% post-tax IRR) support the mineral reserve. A single-phase work program at $4.0 million is recommended to further derisk the project in advance of the next phase of the project.

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2 INTRODUCTION

2.1 Introduction

Ausenco Engineering Canada ULC (Ausenco), Geotechnical Mine Solutions Inc. (GMS), RESPEC Company LLC (RESPEC), SLR International Corporation (SLR) and WSP USA Inc. (WSP) compiled a technical report summary (the Report) on a feasibility study (the FS) completed on the Grassy Mountain Project (the Project) for Paramount Gold Nevada Corp. (Paramount), located in Oregon, USA (Figure 2-1).

This Report updates the previously filed technical report summary entitled, “Grassy Mountain Project: S-K 1300 Technical Report Summary on Feasibility Study, Oregon, United States” with an effective date of June 30, 2022. Updates include the mineral resource estimate, mineral reserve estimate, capital costs, operating costs and the economic analysis.

Paramount owns the Grassy Mountain Project through its wholly owned subsidiary, Calico Resources USA Corp. (Calico).

2.2 Terms of Reference

Measurement units used in this Report are generally U.S. customary; however, some units, such as analytical and metallurgical testwork units may be in metric units. Unless otherwise stated, all monetary amounts are in United States dollars (USD).

Mineral Resources and Mineral Reserves are reported in accordance with subpart 229.1300 of the S-K 1300 reporting requirements.

2.3 Qualified Persons (QP)

The following third-party QP firms contributed to the preparation of this Technical Report Summary:

• Ausenco

• GMS

• RESPEC

• SLR

• WSP

Paramount contributed to Sections 1.2, 1.3, 1.4, 3.1, 3.2, 3.3, 3.4, 3.6, 3.7, 3.8, 4, 20, 21 and 22.2 of this Technical Report Summary.

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Figure 2-1: Project Location Plan

Source: Gustin et al., 2018

2.4 Site Visits and Scope of Personal Inspection

2.4.1 Site Inspection by the Qualified Person of Ausenco

Ausenco’s QP, Robert Raponi, conducted a site visit on August 15, 2019, and inspected the area planned for the portal and the general site layout.

2.4.2 Site Inspection by the Qualified Person of GMS

GMS’ QP, Andres Torres, did not conduct a site visit, and relied upon information from other QPs’ site visits.

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2.4.3 Site Inspection by the Qualified Persons of RESPEC

RESPEC’s QPs have visited the project site and/or Paramount’s field office and core logging facility in Vale, Oregon numerous times as the project advanced. The most recent was by Mike Lindholm (geology and resources) and Sterling (Keith) Watson (mine engineering) for one day on January 30, 2026. Paramount provided RESPEC with an overview of the geology and other project information at their core processing facility in Vale. RESPEC observed historical and Paramount paper files, QA/QC samples, core, RC samples, coarse rejects and pulps stored within the building. Although no drilling was being conducted at that time, Paramount provided an overview of the core and RC logging, sample handling, storage and QA/QC procedures. RESPEC then reviewed the geology and observed planned locations for mine facilities at the Grassy Mountain site.

2.4.4 Site Inspection by the Qualified Person of SLR

SLR’s QP, Jeremy Scott Collyard, visited the project site on November 16, 2021 and met with senior technical staff from Paramount. The site visit included an on-site tour with Paramount senior staff, local, State, and Federal permitting agencies to discuss the proposed TSF and TWRSF site.

2.4.5 Site Inspection by the Qualified Person of WSP

WSP’s QP, Christopher MacMahon, conducted a visit to the Project site on August 18, 2016; November 16, 2021, and January 29, 2026. During these visits, Mr. MacMahon met with senior technical staff from Paramount. The August 18, 2016 site visit provided a general overview of the Grassy Mountain deposit area, including access to the Project, potential surface infrastructure locations, and the site of the proposed portal for the underground mine access. The site visit included additional time at Paramount’s core storage and field office facilities in Vale, Oregon, which was used to further review technical aspects of the Project. The November 16, 2021, site visit included an on-site tour with Paramount senior staff, local, State, and Federal permitting agencies to discuss the proposed TSF and TWRSF site. This site visit also included a meet at the Vale field office. The January 29, 2026 site visit included a general overview of the proposed surface facility locations including the TSF, plant, and portal sites. The site visit included additional time at Paramount’s field office facilities in Vale, Oregon, which was used to further review and discuss the Project.

2.5 Effective Dates

The Report has a number of effective dates as follows:

• Mineral Resource estimates: February 28, 2026

• Mineral Reserve estimate: May 15, 2026

• Date of financial analysis that supports the Mineral Reserves: May 27, 2026.

The overall effective date of this Report is the effective date of the financial analysis, which is May 27, 2026.

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2.6 Information Sources and References

This Report updates the previously filed technical report summary entitled, “Grassy Mountain Project: S-K 1300 Technical Report Summary on Feasibility Study, Oregon, United States” completed in 2022. Updates include the mineral resource estimate, mineral reserve estimate, capital costs, operating costs and the economic analysis. This Report is also based in part on internal company reports, maps, published government reports, and public information, as listed in Section 25. Additionally, Ausenco relied on recent updated budgetary quotations from vendors to develop the cost estimates for this report.

Additional information was sought from Paramount employees in their areas of expertise as required.

2.7 Previous Technical Reports

Paramount has previously filed the following technical reports on the Project in Canada which are publicly available on SEDAR+:

• Raponi T. R., Seamons J., Collyard, J. S., MacMahon, C., Dyer, T., and Torres, A. (2022): Grassy Mountain Project: S-K 1300 Technical Report Summary on Feasibility Study, Oregon, United States. Report prepared by Ausenco Engineering Canada Inc., Arrowhead, SLR, RESPEC, GMS, and WSP for Paramount Gold Nevada Corp., effective date June 30, 2022.

• Raponi T. R., Gustin M. M., Seamons J., DeLong R., MacMahon C., Palma L., 2020: Feasibility Study and Technical Report for the Grassy Mountain Project, Oregon, USA: report prepared by Mine Development Associates, Golder Associates, EM Strategies, Geotechnical Mine Solutions and Ausenco Canada Inc. for Paramount Gold Nevada Corp., effective date September 15, 2020.

• Gustin, M.M., Dyer, T.L., MacMahon, C., Caro, B., Raponi, T.R., and Baldwin, D., 2018: Preliminary Feasibility Study and Technical Report for the Grassy Mountain Gold and Silver Project, Malheur County, Oregon, USA: report prepared by Mine Development Associates, Golder Associates and Ausenco Canada Inc. for Paramount Gold Nevada Corp., effective date May 21, 2018.

Prior to Paramount’s Project interest, the following technical reports were filed on the Project:

• Wilson, S.E., Pennstrom, W.J. Jr., Batman, S.B., and Black, Z.J., 2015: Amended Preliminary Economic Assessment, Calico Resources Corp., Grassy Mountain Project, Malheur County, Oregon, USA: report prepared by Metal Mining Consultants Inc. for Calico Resources Corp., effective date January 13, 2015, amended July 9, 2015.

• Brown, J.J., Malhotra, D., and Black, Z., 2012: NI 43-101 Technical Report on Resources, Grassy Mountain Gold Project, Malheur County, Oregon: report prepared by Gustavson Associates for Calico Resources Corp., effective date September 26, 2012.

• Hulse, D.E., Brown, J.J., and Malhotra, D., 2012: NI 43-101 Technical Report on Resources, Grassy Mountain Gold Project, Malheur County, Oregon: report prepared by Gustavson Associates for Calico Resources Corp., effective date March 1, 2012.

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• Lechner, M.J., 2011: Grassy Mountain NI 43-101 Technical Report, Malheur County, Oregon: report prepared for Calico Resources Corp., effective date June 6, 2011.

• Lechner, M.J., 2007: Grassy Mountain Technical Report, Malheur County, Oregon: NI 43-101 Technical Report: report prepared for Seabridge Gold Inc., effective date April 27, 2007.

2.8 Currency, Units, Abbreviations and Definitions

All units of measurement in this report are metric, and all currencies are expressed in US dollars (USD) unless otherwise stated. Contained gold metal is expressed as troy ounces (oz), where 1 oz = 31.1035 g. All material tonnages are expressed as short tons (tons) unless stated otherwise. A list of abbreviations and acronyms is provided in Table 2-2, and units of measurement are listed in Table 2-3.

Table 2-1: Abbreviations and Acronyms

Abbreviation		Description
AA		atomic absorption
ABA		acid-base accounting
AACE		Association for the Advancement of Cost Engineering
AAL		American Assay Laboratory
ABA		acid-base accounting
Ag		silver
AgEq		silver equivalent
As		arsenic
ASTM		American Society for Testing and Materials
Atlas		Atlas Precious Metals
Au		gold
AuEq		gold equivalent
Ausenco		Ausenco Engineering Canada ULC
AVRD		absolute value of relative differences
BLM		Bureau of Land Management
Calico		Calico Resources USA Corp./Calico BC
Chemex		Chemex Analytical Laboratories
CIL		carbon-in-leach
CIP		Carbon-in-pulp
CIM		Canadian Institute of Mining, Metallurgy, and Petroleum
CNWAD		Weak acid dissociable cyanide
COMEX		Commodity Exchange

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Abbreviation		Description
Cone		Cone Geochemical Laboratories
CPA		Consolidated Permit Application
CRF		cemented rock fill
CRM		certified reference material
Cryla		Cryla LLC
CSAMT		controlled-source audio-frequency magnetotelluric
CT		carbon total
Cu		copper
CUP		Conditional use permit
DO		dissolved oxygen
DOGAMI		Department of Geology and Mineral Industries
EE		Environmental Evaluation
EIS		Environmental Impact Statement
EM Strategies		EM Strategies Inc.
EPCM		Engineering, Procurement, and Construction Management
Fe		iron
FS		Feasibility Study
G&A		General and Administrative
GCL		Geosynthetic clay liner
GMS		Geotechnical Mine Solutions
Golder		Golder Associates Inc.
GPS		global positioning system
Hazen		Hazen Research Inc.
HDPE		high-density polyethylene
Hg		mercury
Hunter		Hunter Mining Laboratories
ICP-AES		inductively coupled plasma atomic-emission spectrometry
ID3		inverse-distance to the third power
IDS		International Directional System
IEC		International Electrotechnical Commission
IP		Intellectual property
IRR		internal rate of return
ISO		International Organization for Standardization

Grassy Mountain Project S- K 1300 Technical Report Summary Page 29 May 27, 2026

Abbreviation		Description
JK		Julius Kruttschnitt
LHD		Load-haul-dump
LOM		Life of Mine
LTF		licencing timeframe
LUCS		Land Use Compatibility Statement
Major Drilling		Major Drilling America Inc.
MCC		Motor control centers
MDA		Mine Development Associates, Inc.
ML		metal leaching
MNP LLP		Meyers Norris Penny
MOP		Mean of pairs
MOU		Memorandum of Understanding
MSHA		Mine Safety and Health Administration
MTO(s)		Material Take-off(s)
NaCN		sodium cyanide
NAG		net-acid generating
NEPA		National Environmental Policy Act
Nevada Select		Nevada Select Royalty Inc.
Newmont		Newmont Exploration Ltd.
NGO		Non-governmental agency
NN		nearest neighbor
NNP		net-neutralizing potential
NOI		Notice of Intent
NPI		net profits interest
NPV		net present value
NSR		net sales revenue
OAR		Oregon Administrative Rule
ODEQ		Oregon Department of Environmental Quality
OK		ordinary-kriging
OWRD		Oregon Water Resources Department
Paramount		Paramount Gold Nevada Corp.
PCC		Project Coordinating Committee
PoO		Plan of Operation

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Abbreviation		Description
Project		Grassy Mountain Project
QA		Quality assurance
QC		Quality control
QP		Qualified Person
RC		reverse circulation
RCE		Reclamation Cost Estimate
RD		relative difference
RDI		Resource Development Inc.
RESPEC		RESPEC Company LLC
RMCG		Rocky Mountain Geochemical Corporation
S2-S		sulfide sulfur
Sherry and Yates		Sherry and Yates, Inc.
SHPO		State Historical Preservation Office
SLR		SLR International Corporation
SO4-S		sulfate- sulfur
SRK		SRK Consulting U.S., Inc.
ST		sulfur total
TIMA		Tescan Integrated Mineral Analyzer
TOC		total organic carbon
Tombstone		Tombstone Exploration Company Ltd
TRT		Technical Review Team
TSF		Tailings Storage Facility
TWRSF		Temporary Waste Rock Storage Facility
UG		underground
U.S.		United States
UTM		Universal Transverse Mercator
WMC		Western Mining Corp
WSP		WSP USA Inc.

Table 2-2: Units of Measurement

Abbreviation		Description
%		percent
% solids		percent solids by weight

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Abbreviation		Description
±		Plus or minus
°		angular degree
°C		degree Celsius
°F		degree Fahrenheit
µm		micron (micrometer)
$/ton		dollars per short ton
a		year (annum)
CAD		Canadian dollar
cm		centimeter
cm3		cubic centimeter
d		day
E		east
EGL		effective grinding length
ft		foot (12 inches)
ft3		cubic feet
g		gram
g/cm3		gram per cubic centimeter
g/L		gram per liter
g/t		gram per metric ton (tonne)
gal		US gallon
gpm		US gallons per minute
h		hour (60 minutes)
ha		hectare
hp		horsepower
in		inch
kg		kilogram
kg/t		kilogram per tonne
km, km2		kilometer, square kilometer
kPa		kilopascal
kV		kilovolt
kW		kilowatt
kWh/t		kilowatt-hour per tonne
L		liter

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Abbreviation		Description
lb		pound
m, m2, m3		meter, square meter, cubic meter
M		million
Ma		million years (annum)
masl		meters above mean sea level
mg		milligram
mi		mile
mm		millimeter
Moz		million (troy) ounces
MPa		megapascal
Mt		million metric tonne
Mton		million short ton
MW		megawatt
N		north
oz		troy ounce
oz/ton		ounce (troy) per short ton (2,000 lbs)
ppb		parts per billion
ppm		parts per million
psi		pounds per square inch
Q		quarter
S		south
s		second
t, tonne		metric tonne (1,000 kg)
ton		short ton (2,000 lbs)
t/d		metric tonnes per day
USD		US dollars
W		west
yr		year

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3 PROPERTY DESCRIPTION

3.1 Introduction

Paramount owns and controls 100% of the mineral tenure, through its wholly-owned subsidiary, Calico which owns and controls 100% of the mineral tenure of the unpatented mining claims, patented mining claims, and mining leases that comprise the Grassy Mountain Project. The Grassy Mountain Project consists of two claims groups that are situated near the western edge of the Snake River Plain in eastern Oregon, 20 miles (mi) south of the town of Vale, Oregon and about 70 miles west of Boise, Idaho (refer to Figure 2-1 and Figure 3-1).

Figure 3-1: Location of the Grassy Mountain Project

Source: Paramount, 2022

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The Grassy Mountain claims group encompasses approximately 9,300 acres located within surveyed townships in Malheur County.

The geographic center of the Grassy Mountain claims group is located at 43.674° N latitude and 117.362° W longitude, and the principal zone of mineralization, the Grassy Mountain deposit, is located at approximately 43.670° N latitude and 117.359° W longitude.

3.2 Mineral Tenure

The Grassy Mountain Project consists of 436 unpatented lode and mill site claims, three patented claims, and a land lease for 28 unpatented lode mining claims Figure 3-2 and Figure 3-3. Patented claims were individually surveyed at the time of location. Unpatented claim boundaries were established initially by handheld GPS units, and in 2011 by onsite survey work. Claim information is provided in Appendix A.

Unpatented claims are subject to annual U.S. Bureau of Land Management (BLM) fees of $200 per claim. The unpatented annual claim fees have been paid and are not due until September 1, each year. Patented claims are subject to annual property taxes of $122 per year. Taxes for the 2024–2025 tax year have been paid; taxes for the coming year are due December 2026.

Calico, a wholly-owned subsidiary of Paramount, owns and controls 100% of the mineral tenure of the unpatented mining claims, patented mining claims, and mining leases that comprise the Grassy Mountain Project. Calico acquired all right, title, and interest in the Project pursuant to a “Deed and Assignment of Mining Properties” between Seabridge Gold Inc., Seabridge Gold Corporation (collectively Seabridge Gold), and Calico dated February 05, 2013.

3.2.1 Mineral Concession Payment Terms

Annual property holding costs, including those to the Bureau of Land Management and to Cryla LLC (Cryla), total $98,142.

3.2.2 Land Access and Ownership Agreements

Paramount’s 100% ownership of the Grassy Mountain Project is subject to the underlying agreements summarized in the following subsections.

3.2.3 Seabridge Gold Corporation

All claims and property were transferred to Calico by Seabridge Gold. Seabridge Gold Corporation (Seabridge Gold) is entitled to a 10% net profits interest (NPI) royalty. Pursuant to the Deed of Royalties, dated February 5, 2013 and modified in 2015 (see Section 3.3.1), within 30 days following the day that Calico made a production decision and construction financing was secured, Seabridge may elect to cause Calico to purchase the 10% NPI for C$10 million (M). Otherwise Seabridge will retain the 10% NPI. Seabridge, at the Report effective date, is the second largest Paramount shareholder and has indicated that it will convert its NPI into equity in Paramount, thus the Seabridge NPI has not been included in the FS.

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3.2.4 Sherry and Yates, Inc.

On February 14, 2018, Calico exercised an Option to Purchase whereby Sherry and Yates agreed to sell to Calico all right, title, and interest in three patented and 37 unpatented mining claims. The 2004 Lease and Agreement with Sherry and Yates was then terminated, although Sherry and Yates retained a 1.5% NSR royalty over the claims (see Section 3.3.2).

3.2.5 Cryla LLC

In 2018, Calico signed a 25-year lease agreement with Cryla that applies to 28 unpatented lode mining claims located to the west of the Grassy Mountain deposit (Figure 3-2). Calico is required to make an annual lease payment of $60,000 for the duration of the lease agreement. Calico is eligible to acquire the property for $560,000 plus $3/oz of gold reserves, as defined by a pre-feasibility or higher confidence-level study. Additionally, Cryla retains a NSR royalty based on gold price for mineral produced from their claims (see Section 3.3.3).

Figure 3-2: Grassy Mountain Claim Group

Source: Paramount, 2020

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3.3 Royalties and Additional Encumbrances

3.3.1 Seabridge Gold

Pursuant to the Deed of Royalties, within 30 days following the day that Calico makes a production decision and construction financing is secured, Seabridge Gold may elect to cause Calico to purchase the 10% NPI for 10 million CAD. Otherwise, Seabridge Gold will retain the 10% NPI. Seabridge Gold, as of the effective date of this Report, is the second largest Paramount shareholder.

3.3.2 Sherry and Yates

Sherry and Yates closed the purchase and sale of the three patented and 37 unpatented mining claims under terms of the 2004 Lease and Option Agreement. Sherry and Yates retain a 1.5% royalty of the gross proceeds for the production of minerals from the patented and unpatented claims and a surrounding ¹⁄₂ mile area of interest (Figure 3-3).

Figure 3-3: Sherry and Yates Area of Interest

Source: Paramount, 2020

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3.3.3 Cryla

Pursuant to the Deed of Royalties, Cryla is entitled to a NSR royalty on mineral or products produced from their claims group. Cryla is entitled to a 2% NSR if the gold price is below or equal to $1,500/oz and a 4% NSR if the gold price is above $1,500/oz. Calico is entitled to reduce the NSR to 1% by paying Cryla $800,000 under any circumstances. The Mineral Resources and Mineral Reserves discussed in this Report are outside the area of the Cryla claims group.

3.3.4 Other Encumbrances

There are no other encumbrances, liens, mortgages or legal actions against the properties.

3.4 Environmental Liabilities

Except for the exploration surface disturbance, primarily related to drilling, and the network of groundwater monitoring wells that will need to be reclaimed, there are no known environmental liabilities associated with the Grassy Mountain Project.

All exploration drill holes that are not part of the current approved monitor-well program have been plugged according to Oregon regulations. Surface disturbance that has not been reclaimed will potentially be used for future development activities and access. The groundwater monitoring wells remain in use for ongoing exploration activities and ongoing data-acquisition activities. The disturbance is bonded as described in Section 3.6.

The company has not violated any regulatory requirements, and no fines have been imposed to date.

3.5 Environmental Permitting

There is a valid exploration permit with the DOGAMI and the U.S. Bureau of Land Management (BLM). A bond in the amount of $146,200 is associated with this exploration permit. An existing Notice (OR-068894) with the BLM for four acres of surface disturbance and a monitor well has an associated bond in the amount of $28,211.

A Conditional Use Permit (“CUP”) from Malheur County was approved by the Malheur County Planning Commission in May 2019. The CUP was extended in 2021 and also in July 2025 for an additional two years.

The TSF dam was approved by the Oregon Water Resources Department in July 2020. The approval is valid for five years, and an extension can be requested. However, as the company filed a new Consolidated permit application in December 2021, a new approval is expected. No changes were made to the dam design.

The National Environmental Policy Act (NEPA) permitting process concluded in the final EIS and record of decision being issued by BLM on January 29, 2026. Draft state permits were issued for public comment and review in December 2025 and state agencies are currently in the process of finalizing permits. State permits will be issued at one time and are anticipated to be issued in the second half of 2026.

Permits not obtained but needed for the type and scope of potential mining at Grassy Mountain as outlined in this Report will involve a number of State and local regulatory authorities. The Project will require the environmental permits covering the construction, operation, and closure of the envisioned mine as discussed in Section 17. State permits are anticipated to be received

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Further information on environmental studies, permitting, and social and community impacts is discussed in Section 17.

3.6 Surface Rights

Paramount owns the surface rights in the Grassy Mountain deposit area. The deposit is located within three patented mining claims. The surrounding surface rights associated with the locations of the planned Project surface facilities belong to the Federal government and are managed by the Vale District office of the BLM.

3.7 Water Rights

Paramount holds a water right granted by the Oregon Water Resources Department to Calico. The water right was issued on April 5, 1990, through State of Oregon Water Rights Application G-11847 and Permit G-10994. Use is limited to not more than 2.0 ft³/s (897.6 gpm) measured at the well.

On December 26, 2012, the Oregon Water Resources Department, Water Rights Services Division, granted Final Order Extension of Time for Permit Number G-10994. This extension extended the date for Calico to fully develop and apply water to beneficial use to October 1, 2028. In 2019, Calico submitted an application to OWRD (T-13157) to modify the points of appropriation and place of use, and to clarify language in the permit. On October 16, 2019, the State of Oregon issued a new Permit to Appropriate the Public Waters (G-18337) that replaces the previous permit and includes the requested modifications. This permit does not change the 2.0 ft³/s of water use allowed.

3.8 Summary Statement

The QP is not aware of any significant factors and risks not discussed in this Report that may affect access, title, or the right or ability to perform work on the Project, although the QP is not an expert with respect to such matters.

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4 ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY

4.1 Access

Access to the main Grassy Mountain deposit is provided by Twin Springs Road, a seasonally maintained unpaved road that originates at Russell Road, a paved two-lane county road that joins with U.S. Highway 20 approximately four miles (mi) west of Vale, Oregon. The center of the Project area may be reached from the Twin Springs Road via 2.5 mi of secondary unpaved roads. Winter and wet weather conditions occasionally limit access to the property, although on-site travel is generally possible year-round. Figure 4-1 shows the road access from Vale to the Grassy Mountain claims group.

Figure 4-1: Access to Grassy Mountain Claims Group

Source: Paramount, 2020

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4.2 Physiography

The Project area is in the semi-arid high-desert plateau region of eastern Oregon. The terrain is mainly open steppe with mesas, broad valleys, and gently rolling hills to steeper uplands (Figure 4-2).

Figure 4-2: Photograph of Grassy Mountain Area Looking

Source: photography by Paramount and modified by MDA, 2018

Elevations range from 3,330 to 4,300 ft above mean sea level (amsl) at the main Grassy Mountain area, while elevations at the Frost Area claims group range from 4,400 to 5,000 ft (amsl). Vegetation across the entire area consists of sagebrush, weeds, and desert grasses tolerant of semi-arid conditions.

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4.3 Climate

The climate is of the semi-arid, continental-interior type, with average annual precipitation of about 9.25 inches (in), roughly half of which falls as snow between November and March. Local weather data indicate a mean annual temperature of 52° F, with daily temperatures ranging from an extreme low of -20°F in the winter to extreme highs of 100°F and higher in the summer.

It is expected that mining activities will be conducted year-round. Seasonal road maintenance is anticipated to be sufficient to provide initial access to the site for all personnel and any deliveries related to the mine site and construction. The road will be upgraded for year-round activities during mine construction.

4.4 Water Supply

Water to support current exploration activity is available from on-site wells. Long-term water needs for mining and processing will require additional wells to ensure availability. Existing capacity is as much as 200 gpm from multiple water wells situated near the proposed mill and mine sites.

A new Permit to Appropriate the Public Waters was issued in 2019 (T-18337); refer to Section 3.7. The water extraction rate is sufficient to support the requirements of the proposed mine and processing facility. Project water requirements and sources are described in more detail in Section 15.

4.5 Power

A regional, 500-kV electrical transmission line runs through the southern part of the Project area, about 2.5 mi south of the proposed mine site. However, the high voltage of this interstate transmission line makes it unsuitable as a source of power for the site. Studies and designs have been completed based on a power source from the Hope Substation owned by Idaho Power Company, located along U.S. Highway 20 (Figure 4-3; see also discussion in Section 15).

4.6 Infrastructure

As of the effective date of this Report, groundwater monitoring wells and unpaved access and drilling roads are the only existing infrastructure within the Grassy Mountain Project area. The infrastructure required for the proposed operation is detailed in Section 15.

4.7 Community Services

The community nearest the Project is Vale, Oregon, with a population of approximately 1,700. Vale is the seat of Malheur County and the home of all related government offices. The regional BLM office is also located in Vale.

Fuel, restaurants, lodging, groceries, hardware supplies, and equipment-repair shops are available in Vale. Other logistical support is available in Nyssa and Ontario, Oregon, both of which are located within 30 mi of the Project. Boise, Idaho, a major metropolitan city, is within a 90-minute drive of the Project area. Mining personnel, equipment suppliers, engineering expertise, and telecommunications services are all expected to be available within the area.

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Figure 4-3: Proposed Power Source for the Planned Operation

Source: Paramount, 2018

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5 HISTORY

5.1 Introduction

The information summarized in this section of the report has been extracted and modified from Wilson et al. (2015a), which was drawn from Hulse et al. (2012), with additional information derived from multiple other sources, as cited. A concise early history of the discovery of the Grassy Mountain deposit and other events through to September 1988 was reported by Kelly (1988). RESPEC reviewed this information and believes this summary accurately depicts the history of the Grassy Mountain Project.

Portions of the present Grassy Mountain Project were first staked by two independent geologists, Richard “Dick” Sherry and Eugene “Skip” Yates, in 1984. Atlas Precious Metals (Atlas) acquired the Sherry and Yates interests in the Grassy Mountain area in 1986. Between 1986 and 1991, Atlas conducted extensive exploration of the property that culminated in the discovery and delineation of the Grassy Mountain deposit, as well as the identification of a number of other peripheral exploration targets. Atlas collected extensive geological, mine engineering, civil engineering, metallurgical and environmental baseline data related to the Grassy Mountain deposit that were used to support a 1990 historical feasibility study for an envisioned open-pit heap-leach and milling operation. Atlas then began to consider underground-mining scenarios, but declining gold prices and the perception of an unfavorable permitting environment discouraged Atlas from developing the Project, and the claims group was optioned to Newmont Exploration Ltd (Newmont) in 1992 and Tombstone Exploration Company Ltd (Tombstone) in 1998. In February 2000, Seabridge entered an option agreement with Atlas to acquire a 100% interest in the Grassy Mountain claims group and completed the acquisition in April 2003.

Seabridge did not carry out exploration at the Grassy Mountain Project. In April 2011, Seabridge signed an option agreement granting Calico the sole and exclusive right and option to earn a 100% interest in the claims group. The acquisition of the Grassy Mountain claims group by Calico was completed in 2012. In 2011 and 2012, Calico carried out geologic mapping and sampling and drilled a total of 13,634 feet in 17 holes. Calico also commissioned a geophysical survey to assist in their exploration efforts.

Paramount acquired Calico in 2016.

5.2 1986-1996 Exploration

Historical exploration conducted by previous operators includes exploration programs carried out by Atlas, Newmont, Tombstone, Western Mining Corp. (WMC), and Calico.

5.2.1 Atlas 1986-1992

Atlas carried out geologic mapping and recognized soil geochemistry as an important exploration tool at Grassy Mountain. Most Atlas exploration targets were initially identified by claim-corner soil sampling on 600-ft by 1,500-ft spacings. Atlas conducted additional soil and float sampling on several anomalies and identified a genetic link between

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gold mineralization and silicification. Of the 400 drill holes completed by Atlas, 196 were reverse circulation (RC) holes drilled on 75- to 100-ft centers within what became the Grassy Mountain deposit area. The remaining holes were drilled at other targets within the Grassy Mountain claims group. Atlas also drilled 87 RC holes at the Crabgrass deposit and defined three separate near-surface zones of gold and silver mineralization.

Details and results of the drilling are provided in Section 7.2.1.1.

5.2.2 Newmont 1992-1996

Newmont carried out extensive and locally detailed geologic mapping and conducted both soil and rock-chip sampling. In 1993, Newmont geologists mapped 40 square miles at a scale of 1:6,000 and collected approximately 2,600 soil samples on a 400-ft by 200-ft grid in hopes of identifying anomalies missed by prior Atlas sampling. During 1993 and 1994, Newmont collected more than 400 rock-chip samples and conducted several geophysical surveys, including a ground-based gravity survey along existing roads, airborne magnetic and radiometric surveys over the entire property, and ground-based gradient-array (IP/resistivity) surveys over the Grassy Mountain deposit and several of the satellite prospects. Ground magnetic surveys were conducted at specific areas. Newmont geologists re-logged the remaining Atlas drill core during this period, and eventually the Atlas RC drill chips as well.

In 1994, Newmont drilled 11 inclined core holes designed to intersect and define the geometry of potential high-grade gold zones within the Grassy Mountain deposit. These were followed with one core hole wedged off of the initial core hole, two holes pre-collared by RC and completed with core, and one additional core hole.

Newmont’s 15 holes were all angled and totaled 15,009.5 ft. This drilling defined what Newmont thought could be several gold zones in excess of 0.1 oz/ton Au within an area of the Grassy Mountain deposit measuring approximately 600-ft long by 350-ft wide by 250-ft thick. Mineralization was constrained to the northeast by a single drill hole that failed to encounter high-grade gold. Newmont considered the western extent of the main high-grade zone effectively closed off after encountering only low-grade mineralization (0.012–0.019 oz/ton Au) and local barren quartz–chalcedony veins. Based on the core drilling and mapping and sampling of surface exposures, Newmont geologists concluded that high gold grades at the Grassy Mountain deposit were controlled by narrow, steeply south-dipping quartz-chalcedony veins and clay matrix breccias that would need to be properly represented by grade modeling and resource estimation.

Details and results from the drilling are provided in Section 7.2.1.2.

During 1995 and 1996, Newmont’s activities focused on estimating Mineral Resources at the main Grassy Mountain deposit. No new exploration work was done during this period.

5.2.3 1996 Exploration at Outlying Targets within the Grassy Mountain Claims Group

By 1996, Atlas and Newmont identified and named a number of mineralized and potentially mineralized target areas peripheral to the main Grassy Mountain gold deposit based primarily on rock-chip, float, and soil-sample data. These outlying targets, several of which were drilled to varying extents, are shown in Figure 5-1.

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Figure 5-1: Outlying Target Area Map

Note: Blue lines demark the outer limits of Paramount’s claims group; UTM NAD83 US Feet, Zone 11 projection; contour interval is 10 ft. 5,000-ft grid lines for scale. Dots are drill hole collars through 2012 colored by gold values. Source: Paramount, 2016

5.2.3.1 Wheatgrass

This target area is approximately 1,500 ft southwest of the Grassy Mountain deposit area (Figure 5-1) and was the site of the first drilling on the claims. Wheatgrass may be a lateral continuation of mineralization extending from the main Grassy Mountain deposit that is displaced by down-to-the-west faults. A number of RC drill holes tested this area with some narrow, low-grade intersections being encountered. Most of these historical holes were drilled vertically and are widely spaced.

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5.2.3.2 North Spur

North Spur is 2,000 ft to the north–northeast of the main Grassy Mountain deposit (Figure 5-1). Resistant ledges of silicified sandstone indicate hydrothermal fluids flowed through the North Spur area. Three widely spaced vertical RC holes south of the silicified ledges intercepted elevated gold grades. About 500 ft to the north, a fence of three vertical RC holes is located approximately at the northern margin of the most strongly silicified outcrops. These holes penetrated intervals with generally low gold grades, but they are sporadically mineralized. Review of RC chips and logs from these holes indicates that gold grades decrease down hole as the sandstone intervals transition to more clay-rich units with depth. All of these holes were drilled vertically and did not adequately test for steeply dipping mineralized structures.

5.2.3.3 Crabgrass

The three mineralized areas that comprise the Crabgrass prospect (Figure 5-1) appear to be stratiform and are contained within the flat-lying to gently east-dipping sandstones above clay-rich units, but confidence in these observations is limited by the fact that all the historical holes are vertical and drilled by RC methods. Significant low-grade gold mineralization was encountered in numerous holes, which formed the basis for a historical resource estimate.

5.2.3.4 Bluegrass and North Bluegrass

These targets are located 1.2 miles and 1.6 miles northeast of the Grassy Mountain deposit, respectively (Figure 5-1). Sixteen RC holes were drilled in the area to follow up on rock-chip and float-chip samples with elevated gold contents. Further work is needed to warrant additional drilling.

5.2.3.5 Snake Flats

This area is 2.25 miles to the northeast of the Grassy Mountain deposit (Figure 5-1). The target was identified by mapping float of silicified arkose and sinter boulders. A large mercury, arsenic, and antimony soil anomaly extends down-slope for approximately 3,500 ft to the northeast. This is the most aerially extensive surface geochemical anomaly at the Project other than at Wheatgrass. Some of the samples from the altered boulders yielded elevated gold values; the source area for these boulders appears to be somewhere beneath post-mineral basalt that occurs in the area. Three RC holes were drilled through about 100 ft of the post-mineral basalt before intersecting unaltered sandstone and siltstone. Additional work is necessary to better define drill targets.

5.2.3.6 Wood

The Wood target is 1.2 miles northwest of the main Grassy Mountain deposit area (Figure 5-1). Wood was identified by surface rock and soil sampling, followed by surface trenching. Rock-chip samples that were taken from a small outcrop of weakly silicified volcanic rocks returned elevated gold values. Fifteen shallow RC drill holes were completed in the area, some of which returned encouraging results.

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5.2.3.7 Wally

The Wally, or Big Wally, target is 1.5 miles north–northwest of the Grassy Mountain deposit (Figure 5-1). Soil samples in the Wally area defined overlapping arsenic, mercury, antimony, and gold anomalies that straddle a north-northwest-trending fault shown on the district geology map. Drilling returned some favorable results.

5.2.3.8 Ryegrass

The Ryegrass, or Dennis’ Folly, target is located 1.2 miles north of the Grassy Mountain deposit (Figure 5-1). This area was identified by mapping silicified zones that returned low-level gold values and anomalous mercury in rock-chip samples.

5.2.3.9 Clover

This target is one mile west of the Grassy Mountain deposit (Figure 5-1) and is identified as an area of weakly silicified arkose adjacent to a northeast-trending fault. Rock-chip sampling identified an outcrop containing 25 ppb gold.

5.2.3.10 Bunchgrass

Bunchgrass is an area of modestly elevated mercury, arsenic, and antimony in soil samples located 0.5 miles south of Crabgrass (Figure 5-1). Wilson et al. (2015a) reported that the target area is approximately 750 ft wide.

5.2.3.11 Sweetgrass

Sweetgrass is located approximately 1.75 miles southwest of the Grassy Mountain deposit (Figure 5-1). Sampling of a large float boulder of siliceous sinter returned elevated gold values. Although additional sampling in the area did not return any significant values, more work is warranted to determine the source of this siliceous sinter boulder.

5.3 1998-2016 Exploration

5.3.1 Tombstone 1998

Prior to finalizing their agreement with Atlas, Tombstone reviewed data from previous work and commissioned an economic study of alternative development scenarios. Tombstone subsequently drilled 10 RC holes, six of which were completed with core tails, for a total of 8,071 ft. Tombstone relied heavily on Newmont’s gradient-array IP/resistivity geophysical surveys to define their drilling targets. Details and results of the Tombstone drilling are provided in Section 7.2.1.3.

5.3.2 Seabridge 2000-2010

Seabridge acquired the Grassy Mountains claims group in 2000 and then optioned the property to Calico in early 2011. Seabridge did not conduct any exploration.

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5.3.3 Calico 2011-2016

Prior to the acquisition of Calico by Paramount, Calico geologists conducted geologic mapping and compiled the Atlas and Newmont geology and surface sample data using a geographic information system (GIS) software. During 2011 and 2012, a total of 13,634 ft was drilled in 14 RC and three core holes. Thirteen of these holes were drilled at the Grassy Mountain deposit area and four were drilled to test outlying targets. Details and results of the Calico drilling are provided in Section 7.2.1.4.

In 2012, Calico commissioned a 25.1 line-mile controlled-source audio-frequency magnetotelluric (CSAMT) survey conducted by Zonge Geosciences Inc. (Zonge). The survey lines were oriented N20°W (Figure 5-2) and arranged to cross the trend of known mineralization.

Figure 5-2: Map of 2012 CSMAT Lines

Note: Red lines show CSAMT lines. Blue lines demark the outer limits of Paramount’s claims group; UTM NAD83 US Feet, Zone 11 projection; contour interval is 10 ft. 5,000-ft grid lines for scale. Dots are drill hole collars through 2012 by maximum gold assays. Source: Wright, 2012

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The CSAMT survey was done under the supervision of consulting geophysicist J.L. Wright of Wright Geophysics, Spring Creek, Nevada. Mr. Wright documented the survey methods and parameters, analyzed the processed data provided by Zonge, and made geologic and exploration interpretations in a 2012 report to Calico that included 18 inverted resistivity sections and interpretive overlays in PDF format, as well as ArcGIS and MapInfo electronic data files (Wright, 2012).

The CSAMT survey identified a zone of high resistivity that encompassed the main Grassy Mountain gold deposit (Figure 5-3), which is attributed to the zone of extensively silicified rocks in the deposit area. The high-resistivity response was visible in sectional and plan views of the resistivity inversion; an example is shown in Figure 5-3.

Figure 5-3: CSAMT Inversion: Resistivity at 328 to 656 Feet Below Surface

Note: Blue lines demark the outer limits of Paramount’s claims group; UTM NAD83 US Feet, Zone 11 projection; contour interval is 10 ft. 5,000-ft grid lines for scale. Grey dots are drill hole collars through 2012. Source: Wright, 2012

5.4 Production

There has been no production at the Grassy Mountain Project.

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6 GEOLOGICAL SETTING, MINERALIZATION AND DEPOSIT

6.1 Introduction

The information presented in this section of the report is derived from multiple sources, as cited. RESPEC reviewed this information and believes this summary accurately represents the Grassy Mountain project geology and mineralization, as it is presently understood.

6.2 Regional Geologic Setting

The Grassy Mountain gold–silver deposit is the largest currently recognized epithermal hot-spring precious-metal deposit of the Lake Owyhee volcanic field. The Lake Owyhee volcanic field is located at the intersection of three tectonic provinces: the buried North American cratonic margin, the northern Basin and Range, and the Snake River Plain. During mid-Miocene time, large-volume peralkaline and subalkaline caldera volcanism occurred throughout the region in response to large silicic magma chambers emplaced in the shallow crust (Rytuba and McKee, 1984). The Lake Owyhee volcanic field includes several ash-flow sheets and rhyolite tuff cones that erupted between 15.5 to 15Ma (Rytuba and Vander Meulen, 1991). The district geology surrounding the Grassy Mountain gold deposit is shown in Figure 6-1.

At about 15Ma, subsidence of the Lake Owyhee volcanic field triggered a change in volcanic eruption styles, which resulted in basaltic and rhyolite deposits of limited extents. Volcanism during the middle to late Miocene was characterized by the eruption of small-volume metaluminous high-silica rhyolite domes and flows, small-volume basalt flows, and mafic vent complexes in north- and northwest-trending Basin and Range-type fracture zones and ring structures related to resurgent calderas. Regional subsidence involved the development of extensive grabens and facilitated the formation of fluvial systems and large lacustrine basins. Large volumes of fluvial sediments, sourced in part from the exhumed Idaho Batholith to the east and southeast, were deposited contemporaneously with volcanism and hot-spring activity during the waning stages of volcanic field development (Cummings, 1991). The resulting regional stratigraphic section is a thick sequence of mid-Miocene volcanic rocks and coeval to Pliocene-age lacustrine, volcaniclastic, and fluvial sedimentary rocks. The oldest units encountered are the flow-on-flow Blackjack and Owyhee Basalts (14.3 to 13.6Ma). These basalts are overlain by arkosic sandstone, tuffaceous sandstone, and conglomerates of the Deer Butte Formation.

6.3 Local and Project Geology

Bedrock outcrops in the vicinity of the Grassy Mountain project are typically composed of olivine basalt flows and siltstones, sandstones, and conglomerates of the Miocene Grassy Mountain Formation. These rocks are locally covered with relatively thin, unconsolidated alluvial and colluvial deposits. Erosion-resistant basalt flows cap local topographic highs, including Grassy Mountain proper, which is a prominent northeast-elongate ridge that forms a topographic crest about one mile southeast of the Grassy Mountain gold–silver deposit (Figure 6-1). Arkosic sandstones are encountered at the surface and at depth, but individual beds or sequences have not been correlated across the project area, in part due to lateral sedimentary facies changes and structural offsets. Surface exposures and drill-defined stratigraphy at the Grassy Mountain deposit area reveal complex facies produced during the waning stages of volcanism of the Lake Owyhee volcanic field and development of the coeval Ore-Ida graben (Lechner, 2011).

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Figure 6-1: Grassy Mountain Regional Geology

Source: RESPEC, 2026

Figure 6-2 shows the local stratigraphic column in the vicinity of the Grassy Mountain project. The lowermost unit intersected by drilling at the Grassy Mountain deposit is the Kern Basin Tuff, a sequence of pumiceous crystal tuff that in part displays cross beds and local surge structures and non-welded to densely welded rhyolite ash-flow tuff. Clast

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size, thickness of individual ash units, and bedding structures suggest a source in the Grassy Mountain project area (Cummings, 1991). The Kern Basin Tuff ranges in thickness from 300 ft on the south bluffs of Grassy Mountain proper to at least 1,500 ft in a drill hole beneath the Grassy Mountain gold–silver deposit.

Figure 6-2: Stratigraphic Column for the Grassy Mountain Area

Source: Paramount, 2020

A small local flow-dome of approximately 12.5 Ma and known as the Butterfly Hill Rhyodacite overlies the Kern Basin Tuff (Figure 6-2). However, in most of the project area the Kern Basin Tuff is overlain by a series of fluvial, lacustrine, and tuffaceous sediments that are assigned to the Grassy Mountain Formation (Cummings, 1991). These sedimentary

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units include granitic-clast conglomerate, arkosic sandstone, fine-grained sandstone, siltstone, tuffaceous siltstone, and mudstone (Figure 6-2). The sedimentary units of the Grassy Mountain Formation, which host the entirety of the current Grassy Mountain Resources, range from 300 ft to over 1,000 ft in thickness. Several siliceous “terraces” and siliceous-sinter deposits are interbedded with silicified units of the Grassy Mountain Formation. Terrace construction was apparently episodic and intermittently inundated by fluvial and lacustrine sediments and ash, resulting in an interbedded sequence of siltstone, tuffaceous siltstone, sandstone, conglomerate, and sinter-terrace deposits. Load casts, flame textures, convolute laminations, and other soft-sediment deformation textures are common in both the sinter beds and other sedimentary units (Siems, 1990). The amount and size of the sinter clasts in the sedimentary rocks reflect relative proximity to a terrace. Proximal deposits are angular, heterogeneous, clast-supported breccias of sandstone, siltstone, and sinter with indistinct clast boundaries in a sulfidic mud-textured matrix.

According to Lechner (2007), the sedimentary units of the Grassy Mountain Formation are unconformably overlain by 50 to 100 ft of black-chert pebble conglomerate interbedded with unconsolidated siltstone. This unit is recessive, and it is overlain by flows of olivine basalt assigned to the Grassy Mountain Basalt, and, in the northwestern part of the project area, by the basalt of Negro Rock (Figure 6-2). These mafic lavas are overlain by lacustrine and fluvial siltstone, sandstone, and conglomerate, which are successively overlain by the Rock Springs lacustrine deposits and basalt lavas that together make up the late-Miocene Idaho Group.

6.4 Grassy Mountain Deposit

6.4.1 Geology

The geology of the Grassy Mountain deposit area is shown in Figure 6-3. The deposit is centered beneath a prominent, 150-ft-high, silicified and iron-stained hilltop that consists of hydrothermally altered arkose and interbedded conglomerate of the Grassy Mountain Formation. Bedding is horizontal at the hilltop and dips 10 to 25° to the north–northeast on the northern and eastern flanks. The bedding steepens to 30 to 40° on the west side of the hill due to drag folding in the footwall of the N20°W-striking Antelope fault. The southwest slope is covered by landslide debris of silicified arkose.

Several horizons of laminated silica, from a few inches to several feet in thickness, crop out southwest and north of the deposit area and are interbedded within the arkose, siltstone, and conglomerate of the Grassy Mountain Formation. Geologists interpret these horizons as beds of silica sinter (Figure 6-2), due in part to the presence of fossil reeds, petrified wood, and other fossilized plant debris. Drilling within the Grassy Mountain deposit penetrated through more numerous and much thicker sinter horizons, indicating the sinter was deposited from hydrothermal fluids venting at the paleo-surface within the accumulating fluvial sedimentary sequence.

Drilling has also shown that in the subsurface of the deposit area the arkosic sandstones and conglomerates are interbedded with numerous intervals of siltstone and mudstone, much of which is thinly laminated. Beds with clay-altered ash to lapilli-sized tephra are common, and there are abundant layers rich in organic carbon ± carbonized plant debris. The laminated siltstone and mudstone intervals reflect a predominantly lacustrine setting that was the site of frequent episodic influxes of fluvial sand- to cobble-sized material.

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Figure 6-3: Grassy Mountain Deposit Area Geologic Map

Source: RESPEC, 2026

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6.4.2 Structure

The Grassy Mountain gold–silver deposit is situated within a zone of complex extensional block faulting and rotation. Faults at Grassy Mountain are dominated by N30°W- to N10°E-striking normal faults developed during Basin and Range extension and are inferred to have post-mineral displacement. On the east side of the deposit, these faults are inferred to have down-to-the east movement based on interpreted offsets of a prominent white sinter bed in drill holes, as well as drilled intersections of fault gouge. A set of orthogonal, N70°E-striking high-angle faults of minor displacement are inferred to link the graben faults. One of these, the Grassy fault, has a vertical offset of only 10 to 40 ft or less, although it coincides with the axis of the high-grade core of the deposit.

6.4.3 Alteration and Mineralization

Hydrothermal activity and gold mineralization occurred during the accumulation of the Grassy Mountain Formation, coeval with active sedimentation. Therefore, the water-saturated, unconsolidated sediments required silicic ± potassic alteration to develop sufficient competency to allow for the creation of fractures and structurally induced open space.

Silicification is the principal hydrothermal alteration type associated with gold–silver mineralization at the Grassy Mountain deposit. It takes the form of silica sinter, pervasive silica flooding, and cross-cutting chalcedonic veins, veinlets, and stockworks. Silicification is inferred to be largely controlled by hot-spring vents active during accumulation of the Grassy Mountain Formation. The 300-ft deep main sinter is underlain by a zone of strong silicification with silica flooding and chalcedonic quartz veins.

Small amounts of fine-grained pyrite are present in silicified rocks that have not undergone later oxidation. In some parts of the deposit, particularly within arkose and sandy conglomerate units, silicification is accompanied by potassic alteration in the form of adularia flooding. Orthoclase, present primarily in sand-sized grains and in granitic clasts, is unaffected by potassic alteration, while plagioclase is replaced by adularia. Adularia is extremely fine-grained and is identified microscopically or by cobaltinitrite staining. Silicic and potassic alteration zones are surrounded by barren, unaltered, clay-rich (20–40% montmorillonite), tuffaceous siltstone and arkose with minor diagenetic pyrite.

The Grassy Mountain gold–silver deposit is located largely within the zones of silicic and potassic alteration beginning approximately 200 ft below the surface. The deposit has extents of 1,900 ft along a N60°E to N70°E axis, as much as 2,700 ft in a northwest-southeast direction, and as much as 1,240 ft vertically. The surface expression of mineralization is indicated by weak to moderately strong silicification and iron-staining, accompanied by scattered, 1/8- to 1.0-inch-wide creamy to light-gray chalcedonic veins that fill joints.

The deposit consists of a central, higher-grade core with gold grades of >~0.03 oz/ton Au that is surrounded by a broad envelope of lower-grade mineralization. The central, higher-grade core is almost 1,000 ft long on the N60°E to N70°E axis, 450 ft in width, and 450 ft in vertical extent, and it lies above the Kern Basin Tuff and below a distinctive sinter unit. Representative cross-sections through the deposit are provided in Section 11.7.1 (see Figure 11-1 to Figure 11-4).

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6.4.3.1 Central Higher-Grade Core Zone

Three distinct and overlapping types of gold–silver mineralization are recognized within the central core of the Grassy Mountain deposit: gold-bearing chalcedonic quartz ± adularia veins, disseminated mineralization in silicified siltstone and arkose, and gold and silver in bodies of clay matrix breccia.

Zones of high-grade mineralization are defined by the presence of chalcedonic quartz ± adularia veins. Mineralized quartz ± adularia vein types include single, banded, colloform, brecciated, and calcite-pseudomorphed veins. Colloform veins tend to carry the highest grades (>0.5 oz/ton Au), with visible gold up to as much as 0.02 inches in the longest dimension associated with argentite. Veins with relict bladed calcite texture also contain higher gold grades than the banded and single vein types. Gold mostly occurs as electrum along the vein margins or within microscopic voids. Some veins carry very little grade or are barren. At least some of the higher-grade zones of veins are thought to strike approximately N70°E.

Vein widths range from 1/16 to ~2.0 inches. Individually, such narrow veins are unlikely to have lateral or vertical extents of significance, but vein frequency can average one vein per foot in places. Zones of veining have strike lengths of 400 to 700 ft and vertical extents of 100 to 250 ft at elevations of 3,150 to 3,400 ft. Individual veins are too narrow to trace or correlate from hole to hole. However, the zones of veining have continuity.

A steep southerly dip of the veins (70–85°) is inferred from vein intersection angles with drill core axes and bedding. Veins are mostly perpendicular to bedding, which generally dips 10–25° NNE within the deposit. Vein intersection angles of 10–25° to the core axis were mostly recorded in core holes GMC-001 to GMC-008 angled at -50° at S20°E, compared with 25° to 50° intersection angles in holes GMC-009 to GMC-011 angled -50° at N20°W. The N70°E strike of the vein zones is supported by: 1) surface mapping, 2) vein orientation perpendicular to bedding, 3) grade-thickness contouring, and 4) the overall trend in mineralization with grades in excess of ~0.03 oz/ton Au.

The veins crosscut the silicified sediments and have extremely sharp grade boundaries with the sediments. Vein frequency diminishes abruptly below an elevation of ~3,000 ft at the west–southwest limit of the higher-grade core to ~3,100 ft at the east-northeastern limit. Very few high-grade veins are encountered above the higher-grade core of the deposit.

Within the higher-grade core, high gold grades are also present in silicified siltstone and arkose with no visible veins. In these cases, gold and silver are inferred to be very finely disseminated in a stratiform manner in the silicified rock. Fine-grained pyrite is commonly disseminated in the silicified siltstone and sandstone where oxidation has not occurred. Contacts between siltstone and arkose beds seem to be more favorable and carry higher gold grades. In places, beds of tuff and tuffaceous siltstone appear to be particularly favorable hosts for higher-grade mineralization that lacks associated veins.

Newmont and other later operators referred to the third style of gold–silver mineralization as “clay matrix breccia,” bodies of which may be more prevalent in the lower portion of the higher-grade core of the deposit. These bodies are interpreted to extend at near-vertical angles up and down into the surrounding, low-grade gold-silver envelope. Clay matrix breccias are mainly of clast-supported types and contain sub-rounded to sub-angular, sand- to boulder-sized clasts of silicified and/or veined arkose and siltstone with minor amounts of clay and iron-oxide minerals between the clasts. In drill core, clay matrix breccia intervals are intersected over lengths of as much as several tens of feet, but their

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true thickness and exact orientations are poorly understood, in part because their margins are commonly irregular-to-gradational and not planar, except where structural fabrics related to fault movement are evident. In some cases, it is difficult to discern where clay matrix breccias end and similar fault-related breccias begin. In some places the two are possibly genetically related.

Clay matrix breccias cut—and are therefore paragenetically later than—the silicification and veins. One interpretation is the clay matrix breccias formed by explosive releases of over-pressured water vapor through faults and fractures during boiling in the waning stages of the hydrothermal activity.

6.4.3.2 Lower Grade Envelope

Lower-grade mineralization, generally less than 0.03 oz/ton Au, envelopes the higher-grade core and extends outwards as stratiform mineralized lenses (see Figure 11-1 through Figure 11-4). There are very few visible chalcedonic veins. The gold and silver are inferred to be disseminated within the silicified arkose and siltstone units. Contacts between arkose, siltstone, and sinter appear to have been preferentially mineralized, and beds of tuff and tuffaceous siltstone also were favorable sites for mineralization. Low-grade mineralization is also present in numerous intervals of silica sinter. However, not all sinter intervals are mineralized. Sinter-hosted mineralization may be disseminated or within fractures where the sinter has been structurally disrupted.

6.5 Deposit Types

The geological setting, hydrothermal alteration, styles of gold-silver mineralization, and close spatial and timing associations of the mineralization with siliceous-sinter deposition indicate that Grassy Mountain is an example of the hot-springs subtype of low-sulfidation, epithermal, precious-metals deposits. The Grassy Mountain deposit is characterized by stacked sinter terraces that demonstrate hydrothermal fluids vented at the paleosurface concurrent with lacustrine and intermittent fluvial sedimentation. At a depth of 300 ft, the main sinter at Grassy Mountain is underlain by a zone of intense silicification, within which is located the core of the deposit that is the focus of this report.

Figure 6-4 shows a conceptual, schematic section of a low-sulfidation epithermal system and its variable form with increasing depth, and the typical alteration zonation, which include the distribution of sinter, a blanket of steam-heated advanced argillic alteration, and water-table silicification (Buchanan, 1981; Sillitoe, 1993).

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Figure 6-4: Conceptual Hot-Springs Epithermal Deposit Model

Source: Buchanan, 1981

In the case of Grassy Mountain, the broader lower-grade mineralization extends up to and overlaps multiple, stacked deposits of sinter, reflecting near-surface epithermal mineralization as the sedimentary sequence accumulated.

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7 EXPLORATION

7.1 Exploration

In early 2017, Paramount commissioned an exploration review of the Grassy Mountain project data to evaluate and define exploration drilling opportunities for potential expansion of the known mineralization. This study focused on the area within the Grassy Mountain claims group controlled by Paramount and was carried out and reported by RESPEC (Weiss, 2017).

RESPEC first compiled and evaluated geological and geophysical maps, soil and rock-chip assay data, and aerial images from files supplied by Paramount. During March 2017, RESPEC reviewed RC drill cuttings and core, drill logs, paper maps, cross-sections, and other files at Paramount’s office in Vale. As part of this review, field traverses were made throughout the Grassy Mountain claim group to better understand the geology, rock geophysical response, and effects of hydrothermal alteration.

Based on the field traverses, RESPEC noted the high-potassium zones shown by the Newmont airborne radiometric data are likely controlled by abundant potassium-bearing clasts within exposed stratigraphic units of the Grassy Formation and concluded that they are not the result of extensive potassic alteration. District patterns of low total magnetic intensity visible in the Newmont airborne magnetic maps also appear closely related to stratigraphy and regional faults of the Oregon-Idaho graben rather than major zones of hydrothermal alteration.

Zones of high resistivity defined by the 2012 CSAMT survey correlate in part with the thick volume of silicified rocks that host the Grassy Mountain gold deposit (refer to Section 5). Drill data, including RC chips, show the resistivity high that extends southwest from the deposit toward the Crabgrass deposit and the outlying resistivity high at the Wood area are not the result of extensive silicification (Weiss, 2017). In these areas, the CSAMT high resistivity response may be from the underlying Kern Basin Tuff (Tkt) and rhyodacite of Butterfly Hill (Trd) units.

Weiss (2017) identified four drill targets within the immediate area of the Grassy Mountain deposit and recommended them for limited expansion drilling. Drilling conducted to test these targets is summarized in Section 7.2.2. These near-mine targets have significant uncertainties in their locations due to a lack of confidence in the precise locations, dips, amount of displacement, and timing of the Apache–Coyote and Gopher faults and the northeast-trending fault in the North Spur, all of which are potentially mineralized structures. Nevertheless, Weiss (2017) justified these targets based on their proximity to the proposed underground mine and the opportunity they presented to expand known mineralization, even if only incrementally. Two holes drilled in 2018 as a preliminary test of the North Spur target returned anomalous values.

Weiss (2017) also recognized two separate targets in the outlying Wood prospect as having the potential to host structurally controlled vein or stockwork mineralization.

In addition, Weiss (2017) recommended additional surface work to further define exploration drill targets. This included expansion of the 2012 CSAMT coverage to better understand the subsurface at the Crabgrass, Bluegrass, North Bluegrass, Ryegrass, and Dennis’ Folly areas and infill soil sampling and trenching at the large geochemical anomaly north of Snake Flats.

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In October 2018, Paramount contracted Precision GeoSurveys of Langley, BC, Canada to fly helicopter-borne aeromagnetic and radiometric geophysical surveys over the Grassy Mountain claim group. Precision GeoSurveys flew 734 line-miles with an Airbus AS350 helicopter at 50-meter spacings and a heading of 090°/270°; tie lines were flown at 500-meter spacings at a heading of 000°/180°. The results of this survey show the Grassy Mountain deposit lies within a large magnetic low (Figure 7-1). Magnetic highs outline the extents of intrusive rocks and basaltic units.

Figure 7-1: 2018 Aerial Magnetic Survey of Grassy Mountain Area

Source: Paramount, 2018 and modified by RESPEC, 2026

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7.2 Drilling

Drilling at the Grassy Mountain claim block is summarized in Table 7-1 and shown in Figure 7-2.

Table 7-1: Grassy Mountain Claim Block Drilling Summary

Year		Company		# Holes		Hole Type		Length (ft)		Area
1987–1991		Atlas		193		RC		154,963		Grassy Mtn
1989–1991		Atlas		5		Core		4,153		Grassy Mtn
1989–1991		Atlas		5		RC & Core		3,502		Grassy Mtn
1987–1991		Atlas		187		RC		62,895		Outlying Prospects
1987–1991		Atlas		10		RC		1,884		Water wells
1992–1996		Newmont		13		Core		13,101		Grassy Mtn
1992–1996		Newmont		2		RC & Core		1,909		Grassy Mtn
1998		Tombstone		4		RC		3,145		Grassy Mtn
1998		Tombstone		6		RC & Core		4,926		Grassy Mtn
2011		Calico		3		Core		2,531		Grassy Mtn
2011–2012		Calico		10		RC		8,518		Grassy Mtn
2012		Calico		4		RC		2,585		Outlying prospects
Historical Total				442				264,112
2016–2017		Paramount		3		RC		1,140		Grassy Mtn
2016–2017		Paramount		3		Core		1,933		Grassy Mtn
2016–2017		Paramount		24		RC & Core		19,907		Grassy Mtn
2018		Paramount		2		RC		1,600		North Spur Target
2019		Paramount		2		Core		931		Geotechnical
Paramount Total				34				25,511
All Drilling Total				476				289,623

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Figure 7-2: Locations of Drill Holes Within the Grassy Mountain Claims Group

5.2.3.6 Wood

Source: RESPEC, 2026

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The project database includes a total of 264,112 ft drilled by four historical operators from 1987 through 2012 in 442 drill holes. From 2016–2019, Paramount drilled 34 holes for a total of 25,511 ft to bring the total drilled within the claims group to 476 holes and 289,623 ft. Approximately 77% of the footage drilled was at and adjacent to the Grassy Mountain deposit area. Most of the holes at the Grassy Mountain deposit area were drilled entirely by RC (77% of the total footage). Holes drilled using core methods account for about 12% of the footage drilled in the deposit area, and holes drilled with RC pre-collars and core tails account for about 11% of the total. Figure 7-3 shows the locations of the holes drilled in and near the Grassy Mountain deposit area. Figure 7-2 includes the collar locations of holes drilled to test outlying prospects within the Grassy Mountain claim block. The results of drilling at the outlying prospects are summarized in Section 5.2 and Section 5.3.

Within the Grassy Mountain deposit area, approximately 80% of the holes were drilled vertically or within 3.0° of vertical. Approximately 69% of the core and core-tail holes were inclined at angles less than -80°. Overall results of drilling within the Grassy Mountain deposit are summarized with representative cross-sections presented in Section 11.7.1. The locations of these cross-sections are shown in Figure 7-3. At the outlying prospects—where all the drilling was done with RC methods—approximately 98% of the holes were vertical. Outside the Grassy Mountain deposit area, the median hole depth was 300 ft.

In addition to the holes discussed above, three short, vertical core holes, for a total of 438 ft, were drilled in 2018 to the east of the Grassy Mountain deposit. These holes obtained samples of unaltered and unmineralized basalt that is a potential source of aggregate and mine-backfill material. These samples were used in various geotechnical and geochemical evaluations. Four groundwater-monitoring wells (GM18-31 through GM18-34) drilled by Paramount in 2018 are not included in the drilling summarized in Table 7-1 or on Figure 7-2 and Figure 7-3.

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Figure 7-3: Locations of Holes Drilled in the Grassy Mountain Deposit Area

Source: RESPEC, 2026

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7.2.1 Historical Drilling, 1987-2012

7.2.1.1 Atlas, 1987–1992

In early 1987, Atlas mobilized a small track-mounted rig to drill six holes in two target areas. Drill hole 026-004 intercepted 80 ft of mineralization averaging 0.021 oz/ton Au. Atlas completed a follow up five-hole drill program in the spring of 1988. Drill hole 026-009 is considered the Grassy Mountain deposit discovery hole—it intersected 145 ft of mineralization that averaged 0.075 oz/ton Au. By the end of 1991, Atlas had drilled 227,397 ft in 400 holes. Of the total, Atlas drilled 13 holes as water wells and 187 holes at outlying prospects.

Eklund Drilling Company of Elko, Nevada drilled Atlas’s RC holes using Ingersoll Rand TH-60 and RD-10 truck-mounted drills with a nominal hole diameter of 5¹⁄₄ inches (Lechner, 2007). Atlas sampled the RC cuttings at 5-ft intervals. Twenty-three of the RC exploration holes were drilled to at least 1,000 ft in depth. (All of the 1,000+-foot holes are in the Grassy Mountain deposit area.) Atlas’s RC drilling was “almost invariably” done dry, because groundwater wasn’t encountered above 750-ft depths except for some locally perched water intersected along the northern portions of the deposit. Because the deposit is strongly silicified, drilling penetration rates were slow and caused excessive bit wear. Drilling in certain areas was difficult because of tight hole conditions and caving of rubble zones. In many cases, historical documentation is not sufficient to determine whether a particular hole was drilled dry or wet.

Atlas drilled 10 core holes at Grassy Mountain to confirm the high-grade mineralization identified by RC drilling, obtain samples for metallurgical testwork, and collect geotechnical data. Longyear, Incorporated (Longyear) drilled two confirmation core holes as NQ (1.875 inch) angle holes. Boyles Brothers drilled five core holes as vertical PQ (3.345 inch) diameter holes specifically to obtain sample material for metallurgical testing (these holes were pre-collared with RC). Boyles Brothers also drilled three geotechnical holes. Assay records indicate that Atlas sampled the confirmation holes on intervals ranging from 0.5 to 7.5 ft in length, with an average sample length of 4.5 ft. RESPEC is uncertain whether the core was mechanically split in half or sawed in half for sampling. Atlas shipped the whole core from the metallurgical holes to Hazen Research Inc. for metallurgical testwork and logged the geotechnical holes for various geotechnical parameters such as rock quality designation (RQD), fracture frequency, etc.

The Atlas geologist assigned to each drill rig was responsible for the placement of the rig, drilling and sampling methods, hole depths, and lithologic logging.

The Atlas drilling discovered and completed the initial delineation of the Grassy Mountain deposit. Atlas also discovered and completed all drilling of the Crabgrass deposit.

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7.2.1.2 Newmont, 1994

In 1994, Newmont drilled 15 angled core holes (including a wedge drilled off the first hole), and pre-collared two of the last three core holes with RC. Longyear of Spokane, Washington conducted this drilling, which totaled 15,010 ft. All these holes were drilled with HQ (2.5 inch) diameter core except for six drill holes in which poor ground conditions forced the HQ core to be reduced to NQ-size. The RC pre-collars were sampled over intervals of 5.0 ft. Newmont sawed approximately 90% of the core in half for sampling and mechanically split the other 10% in half.

Newmont determined that steep, southeast-dipping quartz–chalcedony–adularia veins hosted the high-grade gold. They inferred the steep southeast dip by comparing vein/core intersection angles from southeast-directed holes to those in northwest directed holes and also inferred that the high-grade gold mineralization had a relatively sharp base at an elevation of 3,000 to 3,100 ft.

7.2.1.3 Tombstone 1998

In 1998, Tombstone drilled six core holes with RC pre-collars and four complete RC holes that totaled 8,071 ft of drilling at the Grassy Mountain deposit. Dateline Drilling Incorporated (Dateline) from Missoula, Montana performed all of Tombstone’s RC drilling. Tombstone collected RC samples over 2.5 and 5.0-ft intervals, with both interval lengths sometimes used in the same drill hole. They conducted the RC drilling wet, as water and mud was used for hole conditioning. Ray Hyne Drilling of Winnemucca, Nevada, performed the core drilling. Tombstone sawed approximately 80% of the core in half for sampling and mechanically split the remainder in half.

Tombstone concentrated their drilling in the higher-grade core of the deposit, aiming to better define the higher-grade mineralization. However, the Tombstone results did not include the very high-grade component of the Grassy Mountain mineralization (>2 oz/ton Au) encountered in previous Atlas RC and Newmont core holes (French, 1998). French (1998) theorized that the lack of very high-grade intersections might have been due to the program’s drilling and related sampling problems. French (1998) recommended using a more powerful RC rig that could better handle poor ground conditions and would require less hole reaming and conditioning, which would allow uninterrupted drilling and sample collection.

7.2.1.4 Calico 2011-2012

Calico commenced drilling at the Grassy Mountain deposit in August 2011 and drilled three core holes using a modified track-mounted LF-90 core drill operated by Marcus and Marcus Drilling Company, of Post Falls, Idaho (Marcus and Marcus). Marcus and Marcus drilled HQ diameter core using a triple-tube core recovery barrel. Operating 24 hours per day, Marcus and Marcus drilled an average of 39 ft per day and completed 2,530.5 ft of drilling.

In October 2011, a truck-mounted Ingersoll-Rand TH-75 drill operated by Boart Longyear, of South Jordan, Utah, began RC drilling at the Grassy Mountain property. The TH-75 drill utilized a cyclone wet splitter for sample collection, with an approximate 40% split retained in the sample bag. Drill cuttings passed through a cyclone and the splitter then divided them into three streams: one for sampling, one for logging and retention for reference, and the third was discarded to the sump. The Calico geologist site placed a portion of the sample collected for logging into a plastic chip tray labeled with the hole number and the depth from which the sample was taken. The drill helper collected one

Grassy Mountain Project S- K 1300 Technical Report Summary Page 67 May 27, 2026

sample for each 5-ft interval in bags pre-labeled with the sample number under supervision by Calico’s site geologist. The drill helper sealed each sample bag at the drill site. The sample bags remained unopened until they reached the analytical laboratory. After each 20 ft length of drill rod was added to the drill string, Boart Longyear cleaned the hole of material which may have descended while they installed the new section of pipe. The RC drill operated on a single 12-hour daily shift. A Calico on-site geologist monitored the drilling and sample collection, logged the drill cuttings, and collected and stored a portion of the drill cuttings for future reference. The RC drill rig completed nine holes at the Grassy Mountain deposit area totaling 7,668 ft.

Calico allowed their 2011 RC samples to drain at the drill site prior to shipment for assay. Samples received at the assay laboratory had an average weight of 20 lb.

During June 2012, Calico drilled a total of 3,435 ft in five RC holes—one in the Grassy Mountain deposit area, one in the Wheatgrass area, one at the Wood area, and two at the Wally area. Drill contractor Leach Drilling of Dayton, Nevada, performed the work using an Ingersoll-Rand DM25/RC track-mounted rig. Leach Drilling used a cyclone wet splitter for sample collection and retained approximately 40% of each sample in a sample bag for analysis. Calico’s June 2012 sampling procedures were the same as those used in 2011. The drill operated on a single 12-hour daily shift. An on-site Calico geologist monitored the drilling and sample collection, logged the drill cuttings, and collected a portion of the drill cuttings for future reference. Calico completed the 2012 drill program on June 28.

Calico’s 13 holes drilled at the Grassy Mountain deposit area increased the drill density within the higher-grade core of the deposit. Calico’s three core holes provided additional information regarding higher-grade mineralization. The hole drilled at Wheatgrass returned results consistent with existing holes in the target area. The hole drilled at the Wood target was drilled almost 450 ft from the nearest drill hole and returned only very low-grade intersections. The first hole drilled in the Wally area unsuccessfully tested the western extension of previously defined mineralization. The second Wally drill hole returned similar results to the existing Wally drill holes and therefore confirmed the extension of this low-grade mineralization about 200 ft to the north.

7.2.2 Paramount 2016–2019

From 2016–2019, Paramount conducted infill, geotechnical, hydrological, and metallurgical drilling at Grassy Mountain. Paramount’s drilling focused on the central higher-grade core of the deposit and significantly improved Paramount’s knowledge of the continuity and styles of mineralization within the core zone. It also provided samples for geotechnical and metallurgical testing. Paramount’s drill results made an important contribution to the estimation and confidence in the modeling of the Grassy Mountain gold and silver resources presented in Section 11 of this technical report summary.

In 2016 and 2017, Paramount drilled 22,980 ft in a total of 30 holes within the higher-grade core of the Grassy Mountain deposit. The goals of this drilling program included: (i) verifying the historical drill data, particularly the historical RC holes; (ii) increasing the quantity of drill core derived from the higher-grade portion of the deposit; (iii) obtaining better definition of the controls and extents of the higher-grade mineralization; and (iv) obtaining drill core for detailed geotechnical logging and metallurgical testing. In 2018, Paramount drilled two RC holes at the North Spur target, located a short distance to the north of the Grassy Mountain deposit. In 2019, Paramount drilled two geotechnical core holes within the lower-grade peripheries of the Grassy Mountain deposit. The 2019 drilling included a short, 100-ft vertical hole near the planned mine portal and a deeper 831-ft hole drilled at -70° to penetrate an area of the planned underground access ramp. Representative cross-sections of the drilling are in Section 11.7.1. The cross-section locations are shown on Figure 7-3.

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Historical core drilling programs often experienced significant problems due to poor ground conditions, particularly from the uppermost portion of the deposit through to the bottom of the upper sinter package. Therefore, Paramount began to pre-collar the core holes with RC to depths of approximately 400–500 ft, then core drill through the higher-grade core of the deposit.

Paramount contracted Major Drilling America Inc., of Salt Lake City, Utah (Major Drilling or Major) for both the RC and core drilling. Major drilled RC pre-collars with a Schramm T450GT track-mounted drill operated on a single 12-hour daily shift. Major used a 6¹⁄₂ inch diameter RC bit to the planned pre-collar depth and then set 4¹⁄₂ inch steel casing for the entire length of the hole. The RC drill rig moved to the next RC pre-collar location and a core rig drilled the remainder of the hole (as discussed below).

During the RC drilling, Major Drilling injected small amounts of water down the hole to control dust emissions. Major Drilling’s sampling assistant collected RC samples at nominal 5-ft intervals via a cyclone rotary splitter and center discharge tube into 20-inch by 24-inch sample bags that were pre-numbered by Paramount geologists or geotechnicians. Typical samples weighed approximately 15–20 lb for each sample interval. The Major Drilling sampling assistant monitored the drilling, performed the sample collection, and collected and stored a portion of the drill cuttings in plastic chip trays for future reference and logging. Paramount’s onsite geologist trained the sampling assistant on the first seven RC pre-collars.

Paramount and/or Major Drilling’s sampling assistant collected duplicate RC samples at the rate of approximately one per 40 regular sample intervals. For duplicate samples, they collected the primary sample from the center discharge tube of the rotary splitter and collected the duplicate sample from the side discharge tube of the rotary splitter. (At no time did they use a “Y-type” splitter to collect duplicate samples.)

Major Drilling completed the core drilling with two track-mounted drills: a Boart Longyear LF-90 drill and a Boart Longyear LF-230 drill. Both rigs drilled HQ diameter core using a triple-tube type core barrel. Two-man crews operated the core drills 24 hours per day on two 12-hour shifts with a drill foreman also on site. A single water truck and driver hauling water from a well approximately one mile north of the drilling area supplied adequate water for the two drills.

Major began drilling the first RC pre-collar in November 2016 and completed seven RC pre-collars totaling 2,695 ft during the year. In 2016, core totaling 3,078 ft was drilled in six holes. Paramount suspended drilling from mid-December 2016 through early March 2017. During March, April, and May of 2017, Major Drilling drilled 20 RC pre-collars totaling 8,556 ft. From March through June of 2017, Major drilled 8,651 ft of core in 21 holes. Table 7-2 shows the footages drilled by pre-collar RC and core methods.

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Table 7-2: Paramount 2016–2019 RC Pre-Collar vs. Core Lengths

Drill Hole		Pre-Collar RC From (ft)				Pre-Collar RC To (ft)				Core From (ft)				Core To (ft)				Total RC				Drill Hole				Pre-Collar RC From (ft)
GM16-01			0				380				—				—				380				0			Stuck hammer
GM16-02			0				400				400				742				400				342
GM16-03			0				380				380				785				380				405
GM16-04			—				—				0				744.5				0				744.5			Geotechnical hole
GM16-05			0				360				360				618				360				258
GM16-06			0				400				400				731				400				331
GM17-07			0				391				391				850.5				391				459.5
GM16-08			0				375				—				—				375				0			Twisted off rods
GM16-09			0				400				400				795				400				395
GM17-10			0				400				400				822				400				422
GM17-11			0				385				—				—				385				0			Stuck hammer
GM17-12			0				395				395				689				395				294			Re-drill of GM16-08
GM16-13			—				—				0				438.5				0				438.5			Twisted off rods
GM16-14			—				—				0				750				0				750			Geotechnical hole
GM17-15			0				320				320				780				320				460
GM17-16			0				480				480				923				480				443
GM17-17			0				480				480				929.5				480				449.5
GM17-18			0				450				450				884.5				450				434.5
GM17-19			0				450				450				857.5				450				407.5
GM17-20			0				380				380				856				380				476
GM17-21			0				460				460				832				460				372
GM17-22			0				500				500				953.5				500				453.5
GM17-23			0				400				400				956				400				556
GM17-24			0				450				450				896				450				446
GM17-25			0				400				400				887				400				487
GM17-26			0				520				520				875				520				355
GM17-27			0				440				440				772				440				332
GM17-28			0				420				420				862				420				442
GM17-29			0				440				440				800				440				360
GM17-30			0				400				400				810				400				410
GM18-35			0				800				—				—				800				0			North Spur
GM18-36			0				800				—				—				800				0			North Spur
GM19-37			—				—				0				831				0				831			Geotechnical hole
GM19-38			—				—				0				100				0				100			Geotechnical hole

Grassy Mountain Project S- K 1300 Technical Report Summary Page 70 May 27, 2026

Major Drilling averaged 142 ft of RC drilling per 12-hour shift and 31.1 ft per drill, per 12-hour shift, for core drilling. Three of the RC pre-collars encountered extremely bad ground conditions that led to premature terminations of the holes and precluded the drilling of core tails.

The drilling program achieved all the goals summarized above. Beyond obtaining core for detailed geotechnical logging and metallurgical testing, the drill core aided in furthering the understanding of the deposit’s geology and confirmed many of Newmont’s conclusions. This understanding formed the base from which the resource model was constructed. Finally, the results of the Paramount drilling program have aided in the verification of the historical data (see the discussion of estimating with and without Paramount drill data in Section 9.1.4).

The results and interpretations of the geotechnical and hydrological data derived from the Grassy Mountain deposit area drilling programs are discussed in Section 13.2 and Section 13.3.

7.3 Drill-Hole Collar and Down-Hole Surveys

For the Atlas drilling, Apex Surveying from Riverton, Wyoming, surveyed the collar locations using a total station. Most holes were not surveyed for down-hole direction and deviation, except four RC holes and all the core holes, which were surveyed using an Eastman down-hole camera (Lechner, 2007).

RESPEC does not know whether Newmont surveyed their collar locations. Newmont had Scientific Drilling from Elko, Nevada, perform down-hole deviation surveys of their holes. Newmont’s handwritten “Drill Hole Summary” sheets indicate that Scientific Drilling surveyed their holes using a “gyro” instrument.

There are no written records regarding the procedures for surveying the Tombstone collar locations (Lechner, 2007). Silver State Surveys of Elko, Nevada, reportedly performed down-hole deviation surveys using a gyroscopic survey tool, but Paramount’s archives contain no written records. No down-hole survey data are available for three of the Tombstone drill holes.

Until Calico’s involvement in the project in 2011, project coordinates were based on a local grid established by Atlas. All Calico and subsequent drill-hole collar surveys were collected directly in UTM coordinates. Section 9.1includes a discussion on the transformation of historical mine-grid collar locations into UTM coordinates.

During 2011 and 2012, Calico personnel surveyed drill collar locations using hand-held Garmin GPS units with a horizontal accuracy on the order of ±10 ft. Later, the collar locations were surveyed with a Trimble, survey-grade GPS to ±0.1 ft. Drill holes were marked in the field with a lath and/or stake.

Marcus and Marcus surveyed the 2011 core holes for down-hole directional deviation using a REFLEX EZ-Track survey instrument to obtain multi-shot readings. International Directional Services (IDS) surveyed the 2011 RC holes for down-hole deviation using a Goodrich-Humphrey surface-recording gyroscopic system. Deviations from planned orientations were generally on the order of 3° for core and RC holes, although some of the RC holes deviated by up to 6° in azimuth and 8° in dip.

Down-hole surveys were not performed in the first four 2012 RC holes. IDS surveyed the final 2012 hole, CAL12R17, using a Goodrich-Humphrey surface recording gyroscopic system.

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During Paramount’s 2016–2017 drilling program, Atlas Land Surveying of Fruitland, Idaho, surveyed the Paramount drill-collar locations and many of the historical drill collars (see Section 9.1.1). The coordinates for the 2018 and 2019 holes were determined by handheld GPS. The owner of Atlas Land Surveying, Dean J. Coon, is a Registered Professional Land Surveyor (Oregon 65687LS) and was responsible for the field work, data processing, and reporting. Atlas Land Surveying completed all 2018–2019 survey work using real-time kinematic (RTK) surveying techniques with Topcon Hiper V GPS Receivers. In RTK mode, the stated accuracy of the measurements is within 10 mm ±1 mm for horizontal data and 15 mm ±1 mm for vertical data. Atlas Land Surveying collected static data in the field and then submitted it to the National Geodetic Service Online Positioning User Service to derive accurate geodetic coordinates tied to the National Spatial Reference System. Using these coordinates, a survey measurement adjustment program, “StarNET”, processed the RTK data to determine the final coordinates for the located points, then projected to the Universal Transverse Mercator grid using the NAD83 datum in units of U.S. Survey feet.

Down-hole deviation surveys were obtained from 25 of the 2016 and 2017 Paramount drill holes, the two holes drilled in 2018, and the deeper of the two geotechnical holes drilled in 2019. IDS of Elko, Nevada, performed these surveys using a Goodrich surface-recording gyroscopic system (SRG). The SRG is capable of mapping the direction of boreholes and is unaffected by steel pipe or local magnetic-field anomalies. Five of the 2016–2017 drill holes had blockages, such as lost or stuck pipe, casing, or core barrel, that prevented down-hole surveys.

7.4 Sample Quality

7.4.1 Core Samples

Due to the presence of visible gold in the drill core, Newmont decided to evaluate the potential for unrepresentative loss of gold in the splitting of drill core for sampling. During the sampling of their first hole (GMC-001), Newmont collected the minus 10 mesh fines produced during the sawing of drill core into halves for each sample and weighed and assayed them separately (Jory, 1993). Jory (1993) reported that the mean of the gold assays of the 171 samples of saw fines collected was 86% higher (0.044 versus 0.024 oz/ton Au) than the associated half-core samples sent to the laboratory. Jory (1993) noted that since the saw fines accounted for less than 0.5% of the total sample weight, sampling of the saw fines was discontinued. However, Newmont did take 38 additional saw-fines samples for hole GMC-001-9, a core wedge from GMC-001, for which the assay certificate is available. The average of the saw-fines assays is 0.438 oz/ton Au and the mean of the half-core assays is 0.143 oz/ton Au. Newmont did not obtain silver assays for any of their drill samples. The high bias in the saw fines relative to the half-core samples is present at all gold grades, but it increases as the grade increases.

While the unrepresentative loss of gold to the saw fines is not material due to the small amount of these fines relative to half-core samples, these data suggest the potential unrepresentative loss of gold to fines generated by other means. One such possibility is in fines that collect in core boxes from broken intervals, which clearly warrant careful collection and splitting along with the sawing of competent pieces of core. Newmont brushed fines out of the core boxes for each sample interval and split the fines into halves, with one half added to the sample bags of sawed core sent to the assay laboratory and the other half bagged and returned to the core boxes.

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Fines can also be lost below the surface during core drilling. To evaluate this possibility, RESPEC conducted a sample integrity study to evaluate the relationship between geotechnical data (core recovery and RQD) collected during the logging of the core and gold grades. Figure 7-4 summarizes the relationship between gold grade and RQD for all Grassy Mountain core holes for which RQD data are available.

Figure 7-4: Gold Grade vs. RQD

Source: RESPEC, 2018

Each blue bar in the graph includes data within a 20% RQD bin, as indicated on the x-axis (RQDs of 100% and greater report to the “100” bin). The heights of the bars are indicative of the average grade of all intervals within each recovery bin, as shown on the y-axis of the left-hand side of the graph. The total number of RQD intervals in each recovery bin is displayed by the orange line, with the scale provided by the y-axis on the right-hand side of the graph.

Except for the lowest RQD bin, there is a consistent correlation between RQD and gold grade: gold grades increase as RQD decreases. This negative correlation is at least in part due to the relationship of higher-grade mineralization with highly fractured zones that yield low RQD values. In some deposits, unrepresentative loss of soft, clay-rich, and relatively unmineralized material from the recovered drill core occurs in low RQD zones, which would lead to increased grades in the recovered samples of core. However, the Grassy Mountain mineralization of all grade ranges is associated with uniformly strong silicification, so this mechanism of apparent grade increases is unlikely. The negative correlation between RQD and gold grade does not provide evidence for the possibility of losing gold related to fines during drilling. However, the potential for losses cannot be definitively ruled out.

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RESPEC extensively reviewed RQD measurements used in the sample integrity analysis and modified the data, e.g. adjusted RQD values over 100%, to assure their validity. RESPEC did not validate the bulk of the core recovery data, so these data may contain many inconsistencies that should be resolved. The relationship between recovery and gold grade for two Paramount holes is summarized in Figure 7-5. No clear trend is evident at core recoveries of 60% and greater. Gold grades decrease with decreasing recoveries for core recoveries lower than 60%. However, the number of recovery intervals in each bin is relatively low and likely insufficient to support definitive conclusions.

Figure 7-5: Gold Grade vs. Core Recovery

Source: RESPEC, 2018.

7.4.2 RC Samples

Due to the nature of RC drilling, contamination of drill cuttings from intervals above the drill bit is a concern, especially when groundwater is encountered or fluids are added during drilling. The Atlas reportedly drilled RC holes dry unless groundwater was intersected, while Tombstone, Calico, and Paramount drilled their RC holes entirely wet. Comments on geologic logs and other historical documentation suggest that the water table at Grassy Mountain lies near the base of the higher-grade core of the deposit, with “perched” groundwater noted in a few holes at much higher elevations.

Careful inspection of the geological context of RC drill results can sometimes detect down-hole contamination (e.g., anomalous to significant assays returned from samples from post-mineral units), by comparing RC results to adjacent core holes, and by examining down-hole grade patterns.

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Cyclic down-hole grade patterns are evident in some of the RC holes at Grassy Mountain. These cycles consist of elevated gold grades (relative to adjacent samples) in every fourth 5-ft sample, which corresponds with the first sample collected after a 20-ft drill rod change. In a classic case, the first sample yields the highest grade for a given drill rod, while the following three samples gradually decrease in grade. This “decay” pattern in grade is caused by the accumulation of mineralized material (derived from some level in the hole above the drill bit) at the bottom of the hole as the drilling pauses to add a new drill rod to the drill string. When drilling resumes, the first sample has the greatest amount of contamination, and the successive samples are gradually “cleaner” as the accumulated contamination decreases. This cyclical pattern is detectable only in barren or very weakly mineralized rock. Even in cases where low-grade cyclic gold contamination would have a minimal impact on resource estimation, its presence suggests that similar, and possibly more serious, unrecognizable contamination may have occurred higher in the hole within a mineralized zone.

Atlas did not believe down-hole contamination in Grassy Mountain drilling was a “significant or consistent problem,” but did recognize that the bottom of hole 026-034 was potentially contaminated over a 200-ft interval. During the resource modeling and related detailed review of the project data, RESPEC identified 21 drill holes suspected of having down-hole contamination of precious metal values, primarily based on the cyclic pattern described above. These suspect intervals are all at the lowermost portions of holes. They were either excluded from mineral domain modeling or were used to model but explicitly excluded from use in the resource estimation.

7.5 Summary Statement

RESPEC believes that the drilling and sampling procedures provided representative samples of sufficient quality for use in the resource estimations discussed in Section 11. RESPEC is unaware of any sampling or recovery factors that have not been addressed that would materially impact the estimate of mineral resources discussed in Section 11.

Down-hole drilled lengths of the higher-grade gold and silver portions of the deposit, some of which are oriented at high angles, could significantly exaggerate true mineralized thicknesses in cases where steeply dipping holes intersect steeply dipping mineralization. A very high percentage of the Atlas holes were drilled vertically. RESPEC carefully evaluated the possible effects of exaggerated down-hole lengths on the estimation of current resources and believes the model appropriately represents the higher-grade volumes.

The average down-hole length of the sample intervals used directly in the estimation of the resource’s gold and silver grades is 4.76 ft, with a minimum length of 0.3 ft and a maximum of 12 ft. RESPEC considers these sample lengths appropriate for the Grassy Mountain deposit.

Only four of the 177 Atlas RC holes that directly contribute assay data to the resource estimation were surveyed for down-hole deviation. The four Atlas RC holes that were surveyed deviated from 14 to 35 ft horizontally from the drill collar positions to the distinct lower contact of the higher-grade zone (see Section 11), which lies approximately 800 ft below the surface. The average horizontal deviation is 22 ft. In consideration of the block size of the resource model (5 x 10 x 10 ft; model x, y, z) and other factors related to the resource estimation, RESPEC does not consider the demonstrated magnitude of deviation to be a significant issue.

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8 SAMPLE PREPARATION, ANALYSES, AND SECURITY

8.1 Introduction

This section summarizes all information RESPEC knows relating to sample preparation, analysis, and security, and quality assurance and quality control (QA/QC) procedures employed to amass the Grassy Mountain drilling data. RESPEC either supervised the compilation of information from historical records as cited, or received it from Mr. Michael McGinnis, Paramount’s Project Manager.

8.2 Sample Preparation, Analysis and Security

8.2.1 Atlas 1987-1992

Atlas split the RC samples at the drill site to weigh between 8–15 lb (Atlas’s RC samples averaged approximately 12 lb) Atlas collected their RC samples in 10-inch by 17-inch olefin sample bags. At all times, an Atlas geologist was stationed at the drill rig with the drill samples. Atlas split wet RC cuttings using a variable wet-cone splitter positioned below the cyclone and split dry cuttings under the cyclone with a Jones splitter. Project geologists delivered the samples to a secure storage facility in Vale at the end of each shift. Chemex Analytical Laboratories (Chemex) personnel routinely picked up the samples from the Vale storage facility and delivered them to their preparation facility in Boise, Idaho, where Chemex dried the samples at 100°C and then cone-crushed them to minus 1/8 inch. Chemex took 300-g subsamples using a Jones riffle splitter, then reduced these subsamples to 95% passing 100 mesh using a ring and puck pulverizer. They stored coarse-reject materials in storage at the Boise facility for possible future use. Chemex shipped the 300-g pulps to their assay facility in North Vancouver, Canada, where they assayed for gold and silver using 30-g aliquots analyzed by fire assay fusion, primarily with an atomic absorption (AA) finish.

RESPEC does not know what type of certification Chemex had in 1987–1990, if any, but Chemex was a well-known commercial assayer that was independent of Atlas.

8.2.2 Newmont 1992-1996

Jory (1993) reported that Newmont cut their core into halves at the Vale field office with vein apices oriented perpendicular to the saw blade. For material too fine to be swanned, Newmont geologists carefully swept out the core boxes for each sample interval, split the material in half using a Jones splitter, and recombined one half with the half-core sent for assaying. Newmont core boxes in Paramount’s possession include core fines inside zip-lock plastic sandwich bags—presumably representing the remaining half-split of fine material from each sample interval.

According to Jory (1993), Rocky Mountain Geochemical Corporation (RMGC) picked up the core samples from the Atlas storage facility in Vale and delivered them to the RMGC facility in Salt Lake City, Utah, where RMGC prepared and analyzed the samples. A copy of a Newmont report that lacks a title page, states that, “Coarse gold (up to 500 microns) problems necessitated careful sample prep procedures for Grassy Mountain core.” RMGC dried the samples at 100°C, crushed them to minus 10 mesh, split them in half with a Jones riffle splitter, and coarse pulverized them to minus 48 mesh. RMGC ring-pulverized a 200-g split of the minus 48 mesh material to a nominal, minus 150 mesh particle size, and fire assayed a 30-g aliquot with gravimetric and AA finishes.

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Newmont requested screen-fire assays from RGMC on 20 samples from drill holes GMC-001 and -002, for which original gold assays exceeded 0.20 oz/ton Au.

RESPEC has no documentation regarding the sample security methods Newmont employed during their drilling campaigns.

RESPEC does not know what type of certification RMGC had in 1992–1996, if any. However, RMGC was a well-known, independent commercial assayer of that era, and RMGC was independent of Newmont. Newmont completed their check analyses at their in-house laboratory. Those checks were not independent of Newmont, exist only in paper form, and should be added to the project database.

8.2.3 Tombstone 1998

Tombstone passed their RC cuttings through a rotary wet splitter below the cyclone to produce samples weighing 10–15 lb. Tombstone washed the splitter before each new sample was taken and placed a five-gallon bucket under the splitter to collect the wet samples. They then partially decanted the water from the bucket and emptied the RC cuttings and the remaining fluid into the sample bags and rinsed out the bucket to wash any remaining fines into the sample bag. Tombstone closed the sample bags with one-way plastic ties and transported them to the Vale field office, where American Assay Laboratory (AAL) took possession and transported to their laboratory in Sparks, Nevada.

AAL prepared and analyzed Tombstone’s RC and half-core samples. Laboratory personnel dried the samples at 100°C, crushed them to 8 to 10 mesh, and passed the crushed material through a Jones riffle splitter to produce a four-pound subsample, then pulverized these subsamples to 90% -150 mesh, blended them, and took a 350-g split. AAL analyzed for gold by fire assaying a 30-g aliquot of the 350-g split with an AA finish (AAL method FA30), and analyzed for silver with method D210, which included aqua-regia digestion. AAL was independent of Tombstone and remains a well-known commercial laboratory. RESPEC does not know what certification AAL held in 1998, if any.

8.2.4 Calico 2011-2012

Calico personnel transported their 2011 and 2012 drilling samples from the drill sites to the Calico sample handling and core logging facility in Vale. Before moving the core, Calico staff recorded the date, box number, number of boxes transported, and beginning and ending footages of the transported core on a core handling form.

At the logging facility, Calico personnel measured and recorded core recovery and RQD data. A Calico geologist then logged the core, recording lithological, alteration, mineralization, and structural information that included the angle of intersection of faults with the core, fault lineations, fractures, veins, and bedding. Calico then prepared the entire length of core for sampling. Calico geologists based the sample intervals on the geological logs in order to separate different lithologies and styles of mineralization and alteration. Calico’s sample lengths generally did not exceed 5 ft and, where possible, correlated to the 5-ft drilling runs. After completing logging, Calico geologists marked the sample intervals and assigned each one a unique sample identification (sample tag), with the sample tag stapled inside of the

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box at the end of each sample interval. They placed a duplicate sample tag for each interval inside the sample bag and recorded the sample number in the sample tag booklet. If they suspected or observed contamination or down-hole caving, they flagged the interval and didn’t sample it. If any significant veins, veinlets, healed breccias, or other potentially mineralized planar features were present, Calico geologists marked a line down the length of the core to indicate the line along which the core should be sawn or split to ensure the sampler took a representative sample.

Once Calico geologists had completed the core logging and marked all the sample intervals, the core was sprayed with water and photographed. They then moved the core boxes to the sampling station, and a technician either split the core with a hydraulic splitter or cut the core in half with a diamond-blade core saw. The technician placed one half of the split core into a cloth sample bag labeled with the sample number, returning the other half to the core box for future reference. The Calico technician split intensely broken or very soft core in half using a small scoop or putty knife and placed one of the halves in the numbered sample bag. The sample number, the starting and ending footage of the sample interval, the date, and the technician’s initials were recorded on a core cutting/splitting form. The technician then tied the sample bags shut and stored them in the secure core facility until a complete sample batch was ready for shipment.

Typically, Calico allowed the RC samples to drain at the drill site for two to three days before transporting them to their storage and core logging facility in Vale, where they recorded the date and the number of samples transported on a sample handling form. A geologist or technician arranged the samples in a manner that accounted for all samples, blanks, and standards and photographed them prior to shipment to the analytical lab. Calico then air-dried and stored the RC samples until a commercial freight service transported them to the ALS Minerals (ALS) laboratory in Reno, Nevada.

Calico filled out and maintained a complete sample inventory as an Excel spreadsheet to verify that all samples were accounted for and that bags were not damaged prior to shipment. Calico personnel packed drill-core sample bags into rice bags and sealed each rice bag with a numbered security seal. They placed RC samples into super sacks and sealed each super sack with a numbered security seal. Each shipment only included samples from a single drill hole. Calico prepared a sample submittal form with the shipment number, security seal numbers, the sample numbers, the type of analyses requested, and a list of samples to be duplicated. They included a hard copy of the submittal form with the sample shipment and emailed an electronic copy to the laboratory. The personnel who prepared the shipment filled out a chain of custody form that included the sample shipment number, the location the samples were shipped from, the total number of containers in the shipment, the security seal numbers, the name of the person who prepared the shipment, the name of the person who transported the shipment, and the name of the person who received the shipment at the laboratory. The receiving individual at the laboratory completed the form and noted any damage or discrepancies and returned the form to Calico. The driver of each truck was also required to sign off on the chain of custody form.

A commercial freight service transported Calico’s 2011 and 2012 drilling samples to ALS. ALS was independent of Calico and maintained an ISO 9001:2008 accreditation for quality management and ISO/IEC17025:2005 accreditation for gold assay methods.

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ALS crushed the samples to 75% passing <6 mm and then split off a 250-g subsample for pulverization to 85% passing <75 µm (200 mesh). Laboratory personnel processed clean sand through the crusher every five samples, when a technician noted any color change in the sample, and between every sample in the pulverizing step. ALS split pulps to separate a 30-g aliquot for determining gold by fire assay with AA finish (ALS code Au-AA23) and used a separate 5-g aliquot for inductively coupled plasma atomic-emission spectrometric (ICP-AES) determination of silver and 32 major, minor, and trace elements following a 4-acid digestion (ALS code ME-ICP61). If the original gold assay exceeded the 10 g/t Au (0.29 oz/ton Au) upper limit of the analyses, ALS took additional aliquots from the same pulp for fire assay with gravimetric finish (ALS code Au-GRA21). Samples that yielded silver assays greater than 100 g/t Au (2.92 oz/ton Au) were reanalyzed using a 10-g aliquot with a four-acid digestion for silver and an AA finish (ALS code AG-OG62). Samples that assayed greater than 1,500 g/t Ag (44 oz/ton) were reanalyzed using a 30-g fire assay with a gravimetric finish (ALS code Ag-GRA21).

8.2.5 Paramount 2016-2019

Paramount personnel transported samples from Paramount’s drilling programs in 2016 through 2019 from the drill sites to Paramount’s storage and logging facility in Vale. For sample handling, drying, logging, sample marking, core cutting, and packaging, Paramount applied the procedures Calico used for core and RC samples in 2011 and 2012 (Section 8.2.4), with the exception of the two geotechnical core holes drilled in 2019 that remain unsampled as of the effective date. Paramount personnel cut competent core lengthwise into halves with a saw and split highly broken core by hand directly from the box using a brush and spoon in an effort to take a representative half-core sample. (Approximately 10% of the core samples were split by hand.) After logging and sampling by Paramount geologists and technicians, ALS personnel transported core samples from the project office in Vale to ALS sample preparation facilities in either Reno or Elko, Nevada. Paramount and ALS completed chain of custody paperwork and maintained sample security at all times. ALS is a commercial assayer independent from Paramount that maintains an ISO 9001:2008 accreditation for quality management and ISO/IEC17025:2005 accreditation for gold assay methods.

ALS crushed the samples to 75% passing a 6-millimeter mesh and then split off 250-g subsamples for pulverization to 85% passing -<75 µm (200 mesh). ALS technicians processed clean sand through the crusher every five samples, any time they noticed a color change in the sample, and processed clean sand through the pulverizer between every sample in the pulverizing step. Laboratory personnel split the pulps to separate a 30-g aliquot for determining gold by fire assay with AA finish (ALS code Au-AA23), and used a separate 5-g aliquot for ICP-AES determination of silver and 32 major, minor, and trace elements following a four-acid digestion (ALS code ME-ICP61). If the original gold assay exceeded the 10.0 g/t Au upper limit of detection, ALS split further aliquots from the same pulp for fire assay with gravimetric finish (ALS code Au-GRA21). Samples that assayed greater than 100 g/t Ag were reanalyzed using a 10-g aliquot with a four-acid digestion for silver and an AA finish (ALS code AG-OG62) and samples that assayed greater than 1,500 g/t Ag were reanalyzed using a 30-g fire assay with a gravimetric finish (ALS code Ag-GRA21).

8.3 Quality Assurance/Quality Control Procedures

8.3.1 Atlas QA/QC, 1987–1992

Atlas employed two primary QA/QC procedures:

• Random re-sampling of coarse-reject material for samples where the initial assay was greater than approximately 0.020 oz/ton Au

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• Analyses of RC rig duplicates of original 5-ft samples collected at even 100-ft intervals

Periodically, Atlas geologists prepared a list of the initial Chemex assays greater than approximately 0.020 oz/ton Au, and for every 10^th sample on the list, collected the coarse rejects and split them into two one-pound subsamples. Atlas sent these coarse-reject subsamples to Cone Geochemical Laboratories (Cone) in Denver, Colorado, and Hunter Mining Laboratories (Hunter) in Reno, Nevada. Cone and Hunter were independent of Atlas, but RESPEC does not know if these laboratories held certifications at that time. The check samples sent to both laboratories were prepared using the same procedures. Laboratory personnel dried the samples, cone-crushed them to minus 1/8 inch, and split them into 125-g subsamples that were then ring pulverized to minus 150 mesh. From these pulps, the labs analyzed 30-g aliquots by fire assay. Atlas sent the duplicate samples collected at 100-ft down-hole intervals and the original samples to the Chemex preparation facility in Boise, and then to the Chemex assay laboratory in North Vancouver for analysis. Hunter assay certificates indicate that they performed fire-assays with a gravimetrical finish. The available certificate documentation does not indicate what finish the Cone assays used.

Atlas sent the rig duplicates to Chemex along with the original drill samples.

8.3.2 Newmont QA/QC, 1992–1996

Newmont sent 163 check samples to their in-house Newmont Metallurgical Services laboratory in Salt Lake City, Utah for fire assays with AA finishes. The nature of these samples (e.g., pulps, preparation duplicates, or field duplicates) is not known. RMGC assayed the original samples.

Text from an original Newmont report or memorandum that lacks the header page describes the testing of drill core from hole GMC-001-9, which was a wedge off hole GMC-001. Testing three splits entirely consumed the core—both halves of the sawn core and samples of the fines derived from the sawing of the core.

Newmont asked RMGC to reanalyze 98 samples originally analyzed by RMGC. RESPEC does not know the nature of these check samples. Some evidence suggests they were preparation duplicates.

8.3.3 Tombstone QA/QC, 1998

Tombstone sent the following samples to Chemex for check analyses: 14 AAL pulps for pulp-check analyses, 15 two-pound splits of AAL coarse rejects as preparation duplicates, 14 core duplicates, and 15 RC rig duplicates. (The RC rig duplicates were originally collected at approximately even 100-ft intervals.)

Chemex checked the mesh sizes of the 14 AAL pulps prior to analyses. The RC and core duplicates were dried at 100°C and crushed to 65% less than 10 mesh. Laboratory personnel split these coarse-crush samples, along with the preparation duplicates, into 200–300-g subsamples using a Jones riffle splitter, and then ring-pulverized these subsamples to 95% passing 150 mesh. Chemex fire assayed 30-g aliquots for gold and silver using gravimetric finishes.

In addition to the QA/QC testing described above, Tombstone selected 60 AAL coarse rejects from storage and instructed AAL to coarse pulverize the entire sample to minus 60 mesh. AAL split the samples into halves with a rotary splitter, sent one set of the halved samples to Chemex for pulverization to 95% passing 150 mesh and 30-g fire assay analysis with an AA finish. The lab prepared and analyzed the second set of halved samples using the same methods.

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Tombstone referred to these samples as “Assay Prep Checks” and called the more standard preparation duplicates described in the previous paragraph “Reject Checks.”

AAL also routinely completed replicate analyses of AAL original pulps.

8.3.4 Calico QA/QC, 2011–2012

Calico inserted QA/QC samples every 10^th sample in sequence using pre-labeled bags in the same manner as the primary core and RC-chip samples, and grouped drill samples in batches of 36 samples. Each batch contained a field duplicate, a commercially prepared certified reference material (CRM), and a blank. The blanks included commercial blank pulps and coarse basalt rock barren of gold (coarse blanks). Calico inserted all four types of control samples with core samples, but only inserted CRMs and blank pulps with the RC samples.

Calico used the basalt rock coarse blank to monitor contamination potentially introduced during the coarse crushing and pulverization of core samples. The blank pulps monitored for contamination introduced after pulverization.

Three commercial CRMs obtained from CDN Resource Laboratories Ltd. (CDN) were inserted to assess the precision and accuracy of the analyses. These are listed in Table 8-1.

Table 8-1: Grassy Mountain Certified Reference Materials for 2011–2012

CRMID		Certified Value (g/t Au)				2 Std. Dev. (g/t Au)				Submitted No.
CDNGS-P3A			0.338				0.022				55
CD-GS-3J			2.71				0.26				36
CD-GS-8A			8.25				0.60				21

To assess the homogeneity of the sample material and the overall sample variance, Calico had the analytical lab create a preparation-duplicate approximately every 20 samples. During the 2011 drilling program, Calico retrieved 59 sample pulps representing about 5% of the samples from the higher-grade portion of the deposit and shipped them to ALS as check samples.

8.3.5 Paramount QA/QC, 2016–2019

Paramount compiled an electronic database containing all historical and 2016–2019 drilling information. This database was maintained using SQL software and housed in an off-site remote server that is controlled by a third-party database expert. All database inquiries and data requests were routed through this third-party expert. To prevent any unauthorized changes to the Paramount database, their designated data manager and the third-party expert controlled all data. Paramount established QA/QC protocols for data management, verification, validation, and data screening, which consisted of primary and secondary checks on electronic entry of field data, drill-hole data, sample information, assays, and geochemistry. To ensure accuracy, Paramount and the third-party database expert verified and cross-checked all information.

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During the 2016–2019 drilling programs, Paramount inserted nine different commercially prepared CRMs obtained from CDN into the sample sequence for QA/QC purposes (Table 8-2).

Table 8-2: Grassy Mountain Certified Reference Materials Employed by Paramount, 2016–2019

CRMID		Certified Value (g/t Au)				2 Std. Dev. (g/t Au)				Certified Value (g/t Ag)				2 Std. Dev. (g/t Ag)				Submitted No.
CDN-GS-P3A			0.338				0.022								31				30
CDN-GS-P3C			0.263				0.02												26
CDN-GS-P4F			0.498				0.028												22
CDN-GS-P7E			0.766				0.086												28
CDN-GS-1Q			1.24				0.08				40.7				2.2				32
CDN-GS-3J			2.71				0.26												57
CDN-GS-8A			8.25				0.60												27
CDN-GS-10D			9.50				0.56												12
CDN-ME-1414			0.284				0.026				18.2				1.2				36

Paramount’s QA/QC protocols required that standards assayed within the three-standard deviation threshold of the certified target gold value furnished by CDN. One of the CRMs had certified silver target values. If any assays of the CRMs returned values outside the three standard-deviation limits, Paramount evaluated the assays previous to and immediately after the failed sample for accuracy and for cohesiveness with the geology and mineralization. If Paramount suspected that any of the assay results were problematic, the laboratory reanalyzed the samples.

For both core and RC samples, Paramount inserted a white marble chip blank sample. If any blank samples assayed above a 0.10 g/t Au limit, they examined the preceding sample and the sample after the failed sample for contamination or a possible source of contamination. The laboratory reassayed any surrounding, potentially problematic sample assays.

RC rig-duplicate samples were collected at the drill rig.

8.4 Quality Assurance/Quality Control Results

8.4.1 Atlas, 1987–1992

To help verify their drill-hole gold results, Atlas made extensive use of preparation duplicates and field duplicates. Chemex, the primary assay laboratory used by Atlas, analyzed the field duplicates. Atlas sent the preparation duplicates to Cone and Hunter.

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8.4.1.1 Preparation Duplicates

Preparation duplicates are analyses of pulps derived from secondary splits of the coarsely ground material (coarse rejects) that remain after the primary split is taken for the original assay. Preparation duplicates evaluate the variability introduced by subsampling of the coarsely crushed material. Ideally, preparation duplicates should be analyzed by the primary analytical laboratory to eliminate any variability introduced by different techniques employed at a second laboratory. However, Atlas sent their preparation duplicates to two secondary laboratories.

RESPEC compiled the data for Atlas’s 458 preparation duplicates derived from coarse rejects of samples from 89 Atlas drill holes analyzed by Cone. The relative-difference (RD) graph in Figure 8-1 shows the percentage difference (plotted on the y-axis) of each Cone preparation-duplicate assay relative to its paired primary-sample analysis by Chemex. This RD is calculated as follows:

The x-axis of the graph plots the means of the gold values of the paired data (the mean of pairs or MOP) in a sequential but non-linear fashion. The red line shows the moving average of the RDs of the pairs, thereby providing a visual guide to trends in the data that aids in the identification of potential bias. Positive RD values indicate that the duplicate-sample analysis is greater than the primary-sample assay. A total of 17 pairs characterized by unrepresentatively high RDs are excluded from Figure 8-1.

Figure 8-1: Cone Analyses of Preparation Duplicates Relative to Original Chemex Gold Assays

Source: RESPEC, 2018

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The graph suggests a low bias in the Cone gold results relative to the original Chemex assays over significant portions of the grade range of the data. The mean of Cone analyses (0.226 oz/ton Au) is lower than the mean of the original results (0.237 oz/ton Au), and the average RD of the pairs is -7%. (The average RD can be an approximate measure of the degree of bias, although one must be aware of the statistical effects of pairs with anomalously high RDs.) The mean of the absolute value of the RDs (AVRD) is 29%, which is a measure of the average variability exhibited by the paired data.

Hunter analyzed 428 preparation duplicates from the same original sample set as analyzed by Cone (Figure 8-2).

Figure 8-2: Hunter Analyses of Preparation Duplicates Relative to Original Chemex Gold Assays

Source: RESPEC, 2018

In this case, 25 extreme outlier pairs are removed for the purposes of this discussion. The mean of the Hunter analyses is lower than the mean of the original Chemex assays (0.208 vs. 0.221 oz/ton Au), and the average of the RDs is -9%. The AVRD is 34%.

The Hunter and Cone preparation-duplicate data are generally consistent, showing a low bias in the gold results relative to the original Chemex analyses and average variability of approximately 30%. One difference in the duplicate versus original analyses is that the Chemex pulps were prepared to meet a 95% minus 100-mesh particle size, and the Hunter and Cone pulps were pulverized to minus 150 mesh.

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8.4.1.2 RC Field Duplicates

Field duplicates are secondary splits of drill samples that are mainly used to assess the natural grade variability of the deposit and to evaluate the total subsampling variances attributable to splitting both in the field and in all subsequent subsampling steps in the laboratory. Atlas collected field duplicates at the RC drill sites at the same time as the original samples and sent the field duplicates to Chemex together with the original samples. RESPEC compiled the results of 1,252 RC duplicates from 165 holes drilled by Atlas (Figure 8-3; thirty-eight pairs in which both the original and field-duplicate analyses are less than the detection limit are removed, as are 14 extreme outlier pairs).

Figure 8-3: Chemex Analyses of RC Field Duplicates Relative to Original Chemex Gold Assays

Source: RESPEC, 2018

The field duplicates compare well with the original results, and the means of the datasets are identical (0.016 oz/ton Au). The average of the RD is +4%, while the mean of the AVRD is 35%.

8.4.1.3 Miscellaneous QA/QC Samples

In addition to the preparation and field duplicates, in 1990, Atlas sent 32 samples of unknown type (e.g., sample pulps, coarse rejects, or field duplicates) from drill hole 026-034 to Shasta Analytical Geochemistry Laboratory of Redding, California (Shasta) for 30-g fire assays. RESPEC does not know if Shasta had formal accreditation at the time of the Atlas assays. A handwritten note on the paper assay certificate states that these samples consist of a “set of 4^th check assays from [this] hole.” Figure 8-4 compares the Shasta check assays to the original Chemex results. One outlier pair and two pairs in which Chemex overlimit assays were not performed are removed from the graph.

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Figure 8-4: Shasta Check Analyses Relative to Original Chemex Gold Assays

Source: RESPEC, 2018

The paired data compare reasonably well up to a MOP grade of ~0.2 oz/ton Au. At higher grades, the Shasta check assays tend to be lower grade than the Chemex original analyses, although there are too few pairs to make definitive conclusions. The mean of the Shasta analyses (0.462 oz/ton Au) is significantly lower than the mean of the original Chemex assays (0.533 oz/ton Au), but this difference is largely due to the two highest-grade pairs.

In May 1988, Tombstone sent 12 high-grade Chemex pulps from eight Atlas drill holes to AAL for check assaying. One of the pulps did not have the 30 g needed for the one-assay-ton (30 g) gravimetric fire assays. The mean of the 11 check assays (3.835 oz/ton Au) agrees well with the mean of the original Chemex results (3.866 oz/ton Au).

In late 1990, Phelps Dodge Mining Company had four pulps and 27 coarse-reject samples from nine Atlas holes sent to Chemex for assaying. Backup information is not adequate to determine which of the check assays are from pulps versus the coarse rejects. The paired data compare well up to a MOP of approximately 0.14 oz/ton Au. The check assays in the seven pairs at higher grades are on average lower grade than the original results, but again the quantity of data is insufficient to derive statistically valid conclusions.

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8.4.2 Newmont, 1992–1996

8.4.2.1 Preparation Duplicates

In 1993, Newmont had RMGC reanalyze 98 samples originally analyzed by RMGC. Five of the samples did not have sufficient material to assay. The nature of these check samples is uncertain, but the assay certificate includes a column with the heading, “REMARKS”, that state, “To report Original Pulp and New Pulp values for Gold fire and Cyanide.” This suggests the samples were preparation duplicates. Figure 8-5 compares the check results to the originals. Six outlier pairs are excluded.

Figure 8-5: RMGC Check Analyses Relative to Original RMGC Gold Assays

Source: RESPEC, 2018

The duplicates and originals compare reasonably well, and the mean of the checks (0.903 oz/ton Au) is close to the original (0.923 oz/ton Au). The mean of the RD is +2%, while the mean of the AVRD is 15%.

8.4.2.2 Core Field Duplicates

Newmont wedged drill hole GMC-001-9 off drill hole GMC-001. Newmont submitted both halves of the sawed core from the wedge hole for analyses by RMGC. Newmont’s split “A” is presumed to be the original sample in the following analysis and split “B” is considered a core-duplicate sample. In July 1993, Newmont sent the two sets of 73 core samples to RMGC for sample preparation and fire assaying. Figure 8-6 is a RD plot of the data, excluding two pairs that did not have sufficient material to analyze and five outlier pairs.

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Figure 8-6: RMGC Core Duplicate “B” Relative to RMGC “A” Gold Assays

Source: RESPEC, 2018

The core-duplicate values are higher than the originals up to a MOP grade of approximately 0.020 oz/ton Au, then lower than the original at MOP grades of about 0.040 oz/ton Au and higher. The mean of the core duplicates is 0.085 and the mean of the originals is 0.108 oz/ton Au, but if the highest-grade pair is removed, the duplicate mean becomes higher than the original (0.052 and 0.049 oz/ton Au, respectively). The mean of the RD is +2%, while the mean of the AVRD is 30%.

The preparation-duplicate data and core-duplicate data do not identify any significant issues. Taken together, the two datasets suggest the variability attributable to the splitting of core into halves is approximately 15% (core-duplicate AVRD of 30% minus preparation-duplicate AVRD of 15%).

8.4.2.3 Miscellaneous QA/QC Samples

In December 1993, Newmont had RMGC reanalyze the “A” and “B” pulps. These pulp-check analyses for both datasets yielded results extremely close to the original November 1993 assays, with means of RDs of 0% and 1% for the A and B pulp sets, respectively, and AVRDs of 2% in both cases.

As a check on the RMGC results, Newmont completed gold fire assays on 163 samples at their in-house metallurgical assay facility in Salt Lake City, Utah (Jory, 1993). RESPEC does not know the nature of the check samples (pulps, coarse rejects, or field duplicates). The mean (0.970 oz/ton Au) and median (0.080 oz/ton Au) of the Newmont checks reported by Jory (1993) are both slightly higher than the original RMGC mean (0.942 oz/ton Au) and median (0.078 oz/ton Au).

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In addition to Newmont’s sampling and analytical verification programs discussed above, in April 1998, Tombstone sent nine high-grade samples of Newmont “drill cuttings” from seven drill holes to AAL for preparation and 30-g gravimetric fire assays. The AAL analyses had a mean of 11.209 oz/ton Au, which compared well to the mean of 11.25 oz/ton Au from RMGC’s original assays.

8.4.3 Tombstone 1998

8.4.3.1 Replicate Analyses

AAL, Tombstone’s primary assay laboratory, routinely completed replicate analyses of some of the original assays. Replicate analyses use a second aliquot taken from the primary sample pulp and are typically reported on the same certificate as the original assays. For the 10 holes drilled by Tombstone, AAL reported a total of 113 of these analyses on the same certificates that reported the original assays. The replicate analyses show excellent reproducibility of the original assays, with a mean that is almost identical to the original and an average RD of +1%. The mean of the AVRD is 6%, which is somewhat high for replicate analyses.

8.4.3.2 Preparation Duplicates

Tombstone had AAL crush a total of 60 AAL coarse rejects from two drill holes to minus 60 mesh and split into halves. AAL pulverized and analyzed one set of the halves. Tombstone had Chemex do the same to the second set. The results of this modified version of preparation duplicates completed by AAL are shown in Figure 8-7.

Figure 8-7: AAL Preparation Duplicate Analyses Relative to AAL Original Gold Assays

Source: RESPEC, 2018

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The RD graph shows high biases at low and high grades, while a low bias is evident at MOP grades between approximately 0.025 and 0.06 oz/ton Au. The duplicate mean is higher than that of the original samples (0.175 vs. 0.157 oz/ton Au), and the mean of the RDs is +11%.

A RD graph of the Chemex analyses versus the original AAL results shows a roughly similar form as seen in Figure 8-7, although no bias is present. In this case the duplicate mean (0.159 oz/ton Au) matches the original mean well, and the mean of the RDs is +1%. The means of the AVRD is 20%.

The differences between the AAL and Chemex results are likely more a reflection of insufficient data to adequately evaluate the Tombstone preparation duplicates than some internal differences between the two laboratories.

8.4.3.3 Miscellaneous QA/QC Samples

Tombstone sent Chemex a set of original AAL pulps for pulp-check analyses, splits of AAL coarse rejects as preparation duplicates, and some core and RC field duplicates. The mean of 14 pulp-check analyses from three drill holes (0.523 oz/ton Au) is about 5% higher than that of the original AAL analyses (0.499 oz/ton Au). The mean of 15 Chemex preparation duplicates from six drill holes is also higher than the AAL mean (0.447 vs. 0.412 oz/ton Au, respectively). A total of 13 core duplicates from four drill holes yielded a mean (0.119 oz/ton Au) much higher than the original analyses (mean of 0.085 oz/ton Au), but the elimination of one extreme pair (0.414 oz/ton Au for the duplicate vs. 0.080 oz/ton Au for the original) brings the duplicate mean (0.094 oz/ton Au) much closer to the mean of the original samples (0.086 oz/ton Au). The mean of 15 RC duplicates from six drill holes is again higher than the mean of the original samples (0.055 vs. 0.048 oz/ton Au, respectively).

While none of the miscellaneous testwork involves sufficient samples to derive statistically significant conclusions, the check analyses of the various sample sets are consistently higher than the original AAL results.

8.4.4 Calico, 2011–2012

8.4.4.1 Certified Reference Materials

Calico used three sets of CRMs to evaluate the analytical accuracy and precision of ALS’s original analyses of the Calico drill samples. Calico inserted the CRMs into the original sample stream and analyzed them with the drill samples. In the case of normally distributed data, 95% of the CRM analyses are expected to lie within the two standard-deviation limits of the certified value, while only 0.3% of the analyses are expected to lie outside of the three standard-deviation limits. However, most assay datasets from metal deposits are positively skewed.

Figure 8-8 shows a plot of the ALS analyses of CRM CDN-GS-3J, which has a certified value of 2.71 g/t Au (0.079 oz/ton Au). The x-axis plots the certificate numbers by increasing dates.

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Figure 8-8: Chart of ALS Analyses of CRM CDN-GS-3J

Source: RESPEC, 2018

Samples exceeding the three standard-deviation limits are typically considered failures. As it is statistically unlikely that two consecutive analyses of standards would lie between the two and three standard-deviation limits, such samples are also considered failures unless further investigations suggest otherwise. All potential failures should trigger investigation, possible laboratory notification, and possible reassay of all samples included with the failed standard result.

Using the above criteria, two of ALS’s analyses of this CRM are three standard-deviation failures. However, the CRM analyses are biased slightly low from the certified value. If this is taken into account, the low-side failure would not be a failure.

A similar analysis of the CRM CDN-GS-8, which has a certified value of 8.25 g/t Au (0.241 oz/ton Au) shows no bias and no failures, while CDN-GS-P3A has 12 failures out of the 56 ALS analyses. Although nine of the CDN-GS-P3A failures are on the high side (ALS value > certified value), no bias is evident in the data taken as a whole. CDN-GS-8A has a certified value of 0.338 g/t Au (0.010 oz/ton Au).

RESPEC does not know what actions, if any, Calico took in response to the CRM failures.

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8.4.4.2 Coarse Blanks

Calico also inserted coarse blanks into their sample stream. Coarse blanks are samples of barren material that are used to detect possible contamination in the laboratory, which is most commonly introduced during sample preparation stages. For analyses of blanks to be meaningful, the blanks must be sufficiently coarse to require the same crushing and pulverizing stages as the drill samples. A significant number of the blanks also need to be placed in the sample stream within—or immediately following—a set of mineralized samples, which would be the source of most contamination issues. In practice, this is much easier to accomplish with core samples than RC. Blank results that are greater than five times the lower detection limit of the relevant analyses are typically considered failures that require further investigation and possible re-assaying of associated drill samples. The detection limit of the ALS analyses was 0.005 g/t Au, so blank samples assaying over 0.025 g/t Au (0.0007 oz/ton Au) are considered failures.

ALS analyzed a total of 18 Calico coarse blanks in 2011–2012 (Figure 8-9).

Figure 8-9: Chart of ALS Analyses of Coarse Blanks – Calico

Source: RESPEC, 2018

Three of the coarse blank analyses exceeded the failure threshold, and the highest analysis of a blank was 0.100 g/t Au (0.003 oz/ton Au). All three of the failures are associated with previous samples that are significantly mineralized. Although the blank data provide evidence of cross contamination during ALS sample preparation, the magnitude of this contamination is insignificant.

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8.4.4.3 Analytical Blanks

Analytical blanks are used to monitor possible contamination or calibration problems during the determination of gold concentrations. Calico used a blank commercial pulp supplied by CDN Laboratories (CDN-BL-7) in their QA/QC program. ALS analyzed the analytical blank 62 times. Five of those analyses exceeded the 0.025 g/t Au (0.0007 oz/ton Au) threshold. The failures were 0.001, 0.001, 0.003, 0.004, and 0.009 oz/ton Au. Analytical blanks do not commonly generate failures, and the latter three failures are levels that would warrant investigation and potentially corrective action. RESPEC does not know if Calico took any action in response.

8.4.4.4 Field Duplicates

Calico collected 40 RC duplicates and 10 core duplicates that were analyzed by ALS, the primary laboratory. The mean of the RC duplicates (0.030 oz/ton Au) is close to the mean of the original assays (0.032 oz/ton Au). Although the average of the RDs is -9%, the removal of two of the higher-grade pairs with anomalously high RDs changes this average to 4%. The mean of the AVRD of the entire dataset is 21%.

The means of the duplicates and original samples are reasonably close (0.043 and 0.040 oz/ton Au, respectively) considering the lack of pairs. However, the core-duplicate dataset is too small to derive meaningful conclusions.

8.4.4.5 Pulp-Checks

Pulp checks are reanalyzes of the remaining pulps from the original assays. These reanalyzes are typically completed by a second laboratory. Calico sent 59 of ALS original sample pulps to AAL for check assays. Excluding one extreme outlier pair, the mean of the AAL checks compared well with the mean of the original samples (0.206 versus 0.208 oz/ton Au, respectively), and the average of the RDs is -2%. However, the mean of the AVRD is 12%, which is relatively high for pulp-check analyses.

8.4.5 Paramount 2016–2017

8.4.5.1 Certified Reference Materials

Paramount inserted the nine certified CRMs listed in Table 8-2 into the RC and core sample stream.

Of the 270 ALS gold assays of the CRMs, nine analyses exceeded the three standard-deviation limits. Four of these are due to slight high biases in the ALS analyses of GS-P3A and GS-P3C. Of the remaining five cases, three are from analyses of GS-P4F and each high result is only slightly above the high-side failure limits.

8.4.5.2 Pulp Checks

Paramount sent 569 ALS pulps from the 2016–2017 drilling program to AAL for pulp-check analyses (Figure 8-10; eleven outlier pairs are excluded).

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Figure 8-10: AAL Pulp Checks of ALS Original Gold Analyses

Source: RESPEC, 2018

While the means of the duplicate and original analyses are identical (0.066 oz/ton Au), the graph provides evidence of a slight high bias in the AAL check assays. The mean of the RDs is +3%. The mean of the AVRD is 8%.

The silver results also show a high bias in the AAL results compared to the original ALS assays. The mean of the AAL silver analyses is 4% higher than the ALS mean, the average of the RDs is +6%, and the mean of the AVRD is 10%.

8.4.5.3 Coarse Blanks

ALS analyzed a total of 151 of Paramount’s coarse blanks (Figure 8-11), eight of which exceeded the failure threshold.

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Figure 8-11: Chart of ALS Analyses of Coarse Blanks – Paramount

Source: RESPEC, 2018

The failures range from 0.029 to 0.221 g/t Au (0.001 to 0.007 oz/ton Au). Three of the blank analyses exceeded 0.1 g/t Au (0.003 oz Au/t). The failures do not correlate well with mineralization in previous samples, but the data suggests some cross contamination during ALS sample preparation. The magnitude of this potential contamination in the three highest-grade blank analyses warrants investigation and, if appropriate, the re-assaying of the samples that accompany the failures.

8.4.5.4 Preparation Duplicates

ALS prepared and analyzed a total of 153 of Paramount’s preparation duplicates that were analyzed along with the original samples in 29 of the 30 holes drilled by Paramount (Figure 8-12; three outlier pairs were removed).

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Figure 8-12: ALS Gold Analyses Preparation Duplicates – Paramount

Source: RESPEC, 2018

The mean of the gold analyses of the preparation duplicates is very close to the mean of the original assays (0.040 versus 0.039 oz/ton Au), and the average of the RDs is -1%. The mean of the AVRD is 9%. The silver results are very similar to those of gold, with means of the duplicate and original samples of 0.172 and 0.174 oz/ton Ag, respectively. The mean of the RDs is -1% and the average of the AVRD of 9%.

8.4.5.5 Core Field Duplicates

Paramount regularly included RC and core field duplicates with their original samples submitted to ALS. The core duplicates consisted of half splits of the ¹⁄₂-core remaining, creating ¹⁄₄-core samples, from all 27 holes drilled at least in part with core. Fines, consisting of pieces of core too small for sawing, were sampled using a scoop and putty knife to obtain an “eyeball”¹⁄₂-split, a procedure identical to the procedure used for the primary ¹⁄₂-core samples. ALS analyzed a total of 136 core duplicates and 52 RC duplicates on behalf of Paramount. The two datasets require separate evaluation because the splitting methodologies were completely different.

The ¹⁄₄-core duplicates are compared to the original results in Figure 8-13. Five outlier pairs were removed.

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Figure 8-13: Core Duplicates Relative to Original Gold Assays – Paramount

Source: RESPEC, 2018

At mean of pairs (MOP) of up to ~0.02 oz/ton Au, the means of the duplicate and original analyses are identical, although a slight low bias in the duplicate results is evident over much of this grade range. This bias is largely driven by spikes on the graph that are predominantly pairs where the duplicates are lower than the originals. At MOP higher than 0.02 oz/ton Au, variability increases dramatically (AVRD = 40% versus 18% over the lower-grade range) and the duplicate data display both high- and low-bias trends. On average, the duplicate data are lower grade than the original samples—means of duplicates and originals are 0.078 and 0.093 oz/ton Au, respectively, and the mean of the RDs is -16%.

Excluding seven outlier pairs, the silver results for the core duplicates compare well with the original results, with near identical means and an average RD of -1%. The mean of the silver AVRD is 17%.

The core-duplicate gold results led to the submission of 59 additional core duplicates from 10 of the Paramount drill holes that include core. In this case, ¹⁄₂-core samples were submitted, and, with the first set of core duplicates and Newmont results regarding fines in mind (see Section 7.4.1), special care was taken to brush out all fines in the core boxes related to each sample interval and include them in the duplicate samples. The gold analyses of this second batch of core duplicates, excluding two outlier pairs, show excellent correspondence with the original ¹⁄₂-core results up to a MOP grade of ~0.02 oz/ton Au (Figure 8-14).

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Figure 8-14: Second Set of Paramount Core Duplicates Relative to Original Gold Assays

Source: RESPEC, 2018

At higher grades, the core duplicates are systematically higher grade (duplicate mean is 8% higher than the original mean, and average of the RDs is +18%), and as was the case for the first set of core duplicates, variability increases substantially (mean of the AVRD is 33%).

The silver values of the second set of duplicate core samples compare reasonably well with originals. The mean of the duplicates (0.167 oz/ton Ag) is close to the original mean (0.163 oz/ton Ag) considering the relatively small dataset, and the mean of the RDs is +3%. The average of the AVRD is 18%.

It is reasonable to postulate from the core-duplicate data that sampling of the core-box fines derived from higher-grade gold samples may have played a significant role in the core-duplicate gold and silver results. Specifically, native gold particles collecting at the bottoms of the boxes in high-grade samples may have been unrepresentatively lost to both the original half-core samples and the first set of ¹⁄₄-core duplicates. This loss of native gold particles can be attributed to the manual, unsystematic splitting of the core-box fines (fines were sampled with a scoop and putty knife). In contrast, the second set of half-core duplicates likely oversampled gold in the higher-grade samples, as these samples would have incorporated the gold lost from the primary samples (all fines left in the core boxes were brushed into the duplicate sample bags). The possibility of free gold preferentially collecting in fines is supported by the results of Newmont analyses of saw fines (Section 7.4.1). In contrast to gold, silver analyses of both sets of core duplicates compare reasonably well with the original assays.

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8.4.5.6  RC Field Duplicates

A total of 52 RC duplicate samples were collected for assay for 27 of the Paramount drill holes. Most of these drill holes were completed with core. Figure 8-15 compares the duplicate RC assays to the original results.

Figure 8-15:  Paramount RC Duplicates Relative to Original Gold Analyses

Source: RESPEC, 2018

The means of the RC duplicates and originals compare well (0.018 versus 0.019 oz/ton Au, respectively), and the mean of the RDs is -1%. There is a suggestion of a low bias in the graph, although this is not well supported due to the low number of pairs. The average of the AVRD is 23%, which is somewhat lower than expected, but could be due to the lack of higher-grade pairs.

The silver analyses of the RC duplicates are systematically lower than the originals. The mean of the duplicates is 0.092 oz/ton Ag while that of the originals is 0.099 oz/ton Ag, and the average of the RDs is -13%. The cause of this systematic low bias in the silver results is difficult to explain, but perhaps the bias would lessen with more data. The mean of the AVRD is 23%. Considering the presence of native gold, one would expect the gold variability to be higher than that of silver, which supports the conclusion above of the surprisingly low variability in the RC duplicate gold results.

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8.4.6 Paramount 2018–2019

RESPEC did not review in detail the QA/QC results associated with the two 2018 RC holes drilled at the North Spur target, which lies outside of the limits of the current mineral resources. Nor did RESPEC evaluate the QA/QC results associated with the two 2019 geotechnical core—the results of the geotechnical holes were not available to RESPEC until the 2022 resource estimation had been completed. The data for these four holes have not been compiled and evaluated for this report update.

8.4.7 Discussion of QA/QC Results

The available Atlas QA/QC data of consequence (the preparation and field duplicates) suggest that the original gold assay results may be overstated to some extent. However, the average grade of the duplicate dataset is much higher than the average grade of the Grassy Mountain deposit and repeat analyses of only the higher-grade portion of a deposit with free gold can yield results that on average are lower than original assays. Without additional data, it is impossible to know whether there is a positive bias in the Atlas results, although a comparison of resources with and without Paramount drill data suggests there are no material issues with the Atlas data (see Section 8.2.1).

The Newmont QA/QC data do not identify any issues, while it is possible that the Tombstone gold values are slightly understated.

Paramount’s CRM, blank, and preparation-duplicate data revealed no issues. The core-duplicate data suggest that the Paramount gold assays of core, particularly at higher grades, may be understated. These data also serve to emphasize the importance of careful sampling and splitting of core-box fines.

The variability evidenced by the duplicate data from all operators at Grassy Mountain does not exceed normal bounds, especially considering the presence of visible gold.

8.5 Summary Statement

RESPEC is satisfied that the procedures and methods used for the sample preparation, analyses, and security of the historical and Paramount samples are adequate for generating reliable data that is acceptable as used in this report.

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9 DATA VERIFICATION

9.1 Drill-Hole Data

The current Grassy Mountain drill-hole database, which forms the basis for the resource estimates in Section 11, consists of information derived from 472 drill holes. A total of 286 of these holes were drilled in the general area of the Grassy Mountain resource estimates. They include 34 Paramount holes and 252 historical holes.

Prior to the 2016–2017 drilling program, Paramount provided RESPEC with the project drill-hole database. RESPEC then subjected this database to the data verification procedures discussed below and corrections were made as appropriate. After the creation of this verified database, RESPEC updated this database with the information acquired during Paramount’s subsequent drilling programs.

9.1.1 Collar Data

Atlas established a local grid coordinate system following the discovery of the Grassy Mountain deposit in 1988. This local coordinate system remained in use until Calico acquired the project in 2011. Calico transformed all relevant project location data, including the drill-hole coordinates, into UTM coordinates. Calico made the transformation by plotting all drill holes on digital topography of the project area in the local coordinate system, projecting these data onto a USGS topographic base map in UTM zone 11 NAD27 coordinates, and rotating and scaling the local-grid data until the contours generated from the Atlas grid matched those from the USGS topographic map contours as closely as possible. Calico then determined the UTM coordinates of each drill hole. All subsequent drilling programs surveyed holes in these UTM coordinates.

As part of the 2016–2017 drilling program, Paramount re-surveyed all historical drill-hole collars that could be identified in the field—82 Atlas drill holes, six Newmont drill holes, four Tombstone drill holes, and nine Calico drill holes. The survey contractor provided RESPEC with the original digital file, who used this file to compare the new survey locations with those in the existing database. Excluding one drill hole for which the location was known to be incorrect in the original project database, the northings from the new survey differed from the database locations by more than 3 ft in four drill holes, with a maximum change of 7 ft. The eastings differed by more than 3 ft in four drill holes, with a maximum change of 8 ft, and elevations of four drill holes differed by more than 3 ft, with a maximum change of 5 ft. These discrepancies were found in eight of the 101 re-surveyed historical drill holes. Due to the nature of the Grassy Mountain mineralization and the 5 x 10 x 10-ft block size used in modelling, RESPEC does not consider the scale of the discrepancies in the drill-hole locations material to the estimate of mineral resources presented in this report.

The contractor also surveyed the locations of all hole collars in Paramount’s 2016–2017 drill programs. RESPEC used the original digital survey data for the historical and Paramount drill holes to update the drill-hole locations in the project database.

In addition to the drill-hole locations, RESPEC checked the total depths of 47 of the historical drill holes against historical records. The depth of one drill hole was found to be off by one foot.

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9.1.2 Down-Hole Survey Data

Down-hole survey data exists for 43 historical holes drilled in the Grassy Mountain resource area. RESPEC chose to verify 14 of them. Excluding the three Newmont drill holes discussed below, a total of 168 survey intervals from six Atlas drill holes, two Tombstone drill holes, and three Calico drill holes were checked against historical records. RESPEC found two azimuth measurements in the database that were off by <1°, and three inclination errors of <1.5°. One of the azimuth errors and two of the dip discrepancies occurred in a single drill hole (Atlas hole 079-001). RESPEC corrected the project database to match the historical records. RESPEC also added two survey intervals to the project database as a result of the audit.

RESPEC checked the down-hole survey data for three Newmont drill holes. Supporting documentation consisted of Newmont handwritten “Drill Hole Summary” sheets. The project database includes more than twice the number of survey intervals than are listed on the summary sheets, and the database azimuths and inclinations have higher precision than those on the summary sheets. The database values are very close to those in the summary sheets, although the values only match exactly when the precision of the two datasets is identical. The summary sheets appear to be exactly as named—they summarize the down-hole survey data.

There are 209 historical drill holes within in the Grassy Mountain resource area that lack down-hole survey data in the project database. RESPEC checked the drill-collar azimuths and dips for 40 of these holes against historical records and found no discrepancies.

RESPEC used digital data derived directly from the down-hole survey instrument to add the deviation data from Paramount’s drilling programs to the project database. Paramount completed down-hole surveys on 28 of their holes. Down-hole caving precluded surveys for five drill holes, and Paramount collected no deviation data from a short (100-ft depth) geotechnical hole.

9.1.3 Assay Data

The original database provided to RESPEC included a total of 39,124 assay sample intervals from historical holes drilled in the Grassy Mountain resource area. Of these sample intervals, RESPEC checked the database assay values for 6,942 of the intervals from 38 Atlas drill holes, two Calico drill holes, seven Newmont drill holes, and four holes drilled by Tombstone against historical documentation. The audit revealed a total of only five errors in the database gold values, including:

• two intervals with assay values from the assay certificates (0.002 and 0.004 oz/ton Au) that had no values in the database;

• two transcription errors whereby certificate values of 0.001 and 0.002 oz/ton Au were entered into the database as 0.010 and 0.020 oz/ton Au; and

• a value of zero in the database which should have been 0.054 oz/ton Au according to the assay certificate (the zero value was likely mistakenly transcribed from an adjacent column on the assay certificate).

RESPEC found one silver error whereby a 0.28 oz/ton Ag value on the certificate was entered in the database as 0.2 oz/ton Ag.

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In addition to the errors described above, there were 28 sample intervals with database gold and silver assay values of “0” that had no corresponding assays on the certificates—these intervals presumably had no sample recovery.

RESPEC corrected all identified errors and added silver values found for one Atlas drill hole and three Tombstone drill holes that were not in the database.

For Paramount’s 2016–2017 drilling program, RESPEC updated the resource database with digital assay certificates received directly from ALS.

9.1.4 Additional Data Verification

In addition to the verification procedures discussed above, RESPEC conducted extensive verification of the project data throughout the process of resource modeling. As described in Section 11.7.1, RESPEC’s detailed, explicit modeling of the gold and silver mineral domains within the context of the project geology resulted in iterative modifications to the critical mineral-controlling structural model that had been initially interpreted by Paramount. Paramount recognized the importance of lithologic mineralizing controls, which RESPEC confirmed. RESPEC verified Paramount’s lithologic model and used it to guide modeling of the Grassy Mountain deposit’s mineral-domains.

The Paramount drilling also helped verify the historical data. As mineral-domain modeling proceeded, RESPEC continually evaluated the grade and geological consistency between the historical data and the assays of Paramount’s drill holes. This work led to the recognition of potentially contaminated RC sample intervals, which were then excluded from use in the mineral resource estimation.

As a further verification of the historical drilling data, RESPEC completed a test resource estimate that excluded all Paramount drill data. RESPEC then compared the results to the current resource model which included the Paramount data. RESPEC ran the check estimation using the same estimation parameters as those used to estimate the current resources. On a global basis (no cut-off), exclusion of the Paramount drill data resulted in 0.4% fewer gold ounces compared to the current resource estimation. At various cut-offs from 0.005 to 0.090 oz/ton Au, the highest-magnitude change was a 0.9% decrease in gold ounces. The constancy in the ounces estimated using composited assays that included or excluded Paramount data supports the use of historical drilling data in resource estimation.

9.2 Site and Field Office Inspections

9.2.1 Ausenco

Ausenco’s QP visited the Grassy Mountain project on 15 August 2019 and inspected the area planned for the portal and the general site layout.

9.2.2 RESPEC

RESPEC QPs have visited the project site and/or Paramount’s field office and core logging facility in Vale, Oregon numerous times as the project advanced. The most recent was for one day on January 30, 2026. Paramount provided RESPEC with an overview of the geology and other project information at their core processing facility in Vale. RESPEC

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observed historical and Paramount paper files, QA/QC samples, core, RC samples, coarse rejects and pulps stored within the building. Although no drilling was being conducted at that time, Paramount provided an overview of the core and RC logging, sample handling, storage and QA/QC procedures. RESPEC then reviewed the geology and observed planned locations for mine facilities at the Grassy Mountain site.

Prior visits by RESPEC QPs included one day in each of August and November 2016, three days in December 2016, a total of 30 days in January, February, and March 2017, and one day in June 2018. During the past visits, RESPEC reviewed altered and sometimes mineralized outcrops in the Grassy Mountain deposit area at many of the exploration target areas discussed in various sections of this report. The QPs also inspected active core and RC drill sites with ongoing sampling and logging. In addition, RESPEC reviewed drill core from several holes in detail, reviewed all project procedures related to logging, sampling, and data capture and made recommendations where appropriate.

RESPEC assisted Paramount’s geological team with the cross-sectional geological modeling that served as the basis for the resource modeling. These activities involved detailed checking, validation, and in some cases modifications of the Paramount and historical geological data, interpretations, and geological modeling of the Grassy Mountain deposit.

The site and field-office visits materially contributed to RESPEC’s understanding of the project and confidence in the project data.

9.2.3 SLR

SLR’s QP visited the project site on November 16, 2021 and met with senior technical staff from Paramount. The site visit included an on-site tour with Paramount senior staff, local, State, and Federal permitting agencies to discuss the proposed TSF and TWRSF site.

9.3 Summary Statement

9.3.1 Ausenco

In Ausenco’s opinion, the data used for the development of the sections for which Ausenco is responsible are sufficient to support a feasibility study: metallurgical testing and data was completed at certified laboratories and capital and operating costs were developed following AACE guidelines and included development of detailed mechanical and electrical equipment lists, electrical load lists, reagent and consumable consumption calculations, vendor and supplier quotes, and material take-off and benchmarking from the Ausenco database.

9.3.2 RESPEC

RESPEC experienced no limitations in their data verification activities for the Grassy Mountain project. In consideration of the information summarized in Sections 5 through 9 and 11 and 12 of the report, RESPEC consider the Grassy Mountain project data acceptable for use in this report, most importantly to support the estimation and classification of mineral resources and mineral reserves.

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9.3.3 SLR

SLR developed the closure plan and RCE. SLR is responsible for the data verification related to closure. Source data for the development of the closure plan and RCE were provided to SLR by others as it pertains to individual facilities design responsibilities in the feasibility study. SLR has confidence in the validity of the data and the providers of the data considering these data were provided from the PFS, design reports, etc. and utilized for the development and permitting of this project.

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10 MINERAL PROCESSING AND METALLURGICAL TESTING

10.1 Introduction

The Grassy Mountain deposit has been the subject of several historical metallurgical testwork programs between 1991 and 2020. The most recent test programs, completed in 2018 and 2020 in support of this Feasibility Study Update, were carried out at SGS Canada Inc. (“SGS”) in Burnaby, BC and McClelland Laboratories Inc (“McClelland”) in Sparks, NV. A full breakdown of the results for each metallurgical test program can be found in Table 10-1.

Table 10-1: Metallurgical Testwork Summary

Year		Laboratory/Location		Laboratory Certification		Relationship to the Registrant		Testwork Performed
1990, 1991		Hazen Research Inc.		https://www.hazenresearch.com/about/quality-safety		Independent		Comminution tests, gravity concentration tests, flotation tests, leach tests, column leach tests, cyanide detox tests, solids liquids separation tests
1991		Golden Sunlight Mines Inc.		N/A		Independent		Comminution tests, leach tests
1993		Newmont Exploration Inc.		None listed on website		Independent		Column leach tests
2015		RDI Inc.		N/A		Independent		Mineralogy, comminution tests, gravity concentration tests, flotation tests, leach tests, column leach tests, cyanide detox tests
2018, 2020		SGS Canada Inc.		Conforms to the requirements of the ISO/IEC 17025 standard for specific registered tests.		Independent		Mineralogy, comminution tests, gravity concentration tests, leach tests, oxygen uptake tests, solids liquids separation tests, cyanide detox tests
2020		McClelland Laboratories Inc.		ISO/IEC Standard 17025:2017		Independent		Leach tests

During the 2018 PFS, the testwork program was focused on a gravity, leach and adsorption flowsheet comprising:

• Primary grind (80% passing or P₈₀ of 100 mesh or 150 µm)

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• Gravity gold recovery

• Cyanide leaching

• Adsorption in a carbon-in-leach (CIL) circuit

• Cyanide destruction.

During the 2020 FS, the leach flowsheet design was modified to a simpler, lower capital cost alternative comprising:

• Primary grind (P₈₀ of 150 mesh or 106 µm)

• Hybrid leach–CIL circuit

• Mercury removal circuit

• Cyanide destruction.

10.2 Historical Testwork Programs

10.2.1 Historical Studies 1989 to 2012

In support of the FS, historical work conducted by Hazen, Golden Sunlight, Newmont, and Resource Development Inc. (RDI) was reviewed. The degree to which historical metallurgical samples are representative of the Grassy Mountain deposit is not known with certainty, but there is no evidence that the historical samples were not representative. Early historical work listed above is viewed as indicative or informative only since the QP was not able to reconcile the test results to drill hole locations and depth to confirm that these drill holes represent the ore in the current mine plan.

Historical results are presented in Section 10.4, where relevant to the current flowsheet.

10.2.2 Historical Testwork from 2018 PFS

In 2017, Ausenco oversaw metallurgical testing to develop data for the 2018 PFS for the Grassy Mountain Project.

10.2.2.1 2018 PFS Sample Selection

Nine samples were submitted for metallurgical testing. Lithologies were identified by Ausenco, under the guidance of the Paramount technical team. Samples were described as Arkose, Mixed Lithology Drop Weight Test (MLDWT), Mixed Lithology Low Grade (ML-LG), Mixed Lithology Average Grade (ML-1), Mixed Lithology Average Grade (ML-2), Mixed Lithology High Grade (HG), Silt Stone (SLST), Mudstone and Clay Mixed Breccia (CMB).

10.2.2.2 2018 PFS Testwork Scope

PFS testwork was completed but SGS Canada Inc. (SGS) in Burnaby, Canada conducted the metallurgical testing and associated assays shown in Table 10-2 under program 15944-001. SGS conforms to the requirements of ISO/IEC 17025 for specific tests as listed on their scope of accreditation which can be found at www.scc.ca/en/search/palcan/sga.

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10.3 2020 FS Testwork

10.3.1 Objectives

Metallurgical testwork in support of the FS was defined based on review of historical work and consideration of the mine plan prepared during the 2018 PFS. Consideration was also given to potential for optimization, and flowsheet simplification.

The program was designed with the intent to confirm the parameters for the process design criteria for comminution, leaching, carbon adsorption and cyanide destruction in the process plant and to assess recovery as a function of head grade. The metallurgical program was conducted at SGS.

Supplementary work to support recovery estimation was conducted at McClelland Laboratories, Inc (Sparks, Nevada); (McClelland).

10.3.2 SGS Testwork Program 15944-002 Scope of Work

Six samples were sent to SGS for metallurgical testing.

The range of tests and samples used for each test is summarized in Table 10-3.

10.3.3 McClelland Testwork Program MLI 4551 Scope of Work

Twelve samples were sent to McClelland for metallurgical testing.

The testwork program scope included determination of head assays and leach tests.

10.3.4 Sample Selection for SGS Program 15944-02

The composite samples were selected by Paramount with input from Ausenco to represent the production composites for the proposed Year 1 and Year 2 of operations, and the major lithologies, Arkose, Siltstone and Sinter (Table 10-3).

The metallurgical program was performed on the following composites: Year 1, Year 2, Arkose, Siltstone, Sinter and un-used ML-LG sample from the 2017/2018 testwork program.

Since there was insufficient sample available of the Year 1 composite for comminution testing, it was decided to test the comminution properties for each of the major lithologies for Year 1 as an alternative. A low-grade sinter sample was provided for comminution testing.

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10.3.5 Sample Selection for McClelland Program MLI 4551

Samples tested at McClelland were made up from drill core as composites to represent the ore that will be mined during the first two years of production. Twelve grade variability composite samples (4551-001 to 012) and one master composite sample (4551-013) were tested. Variability composite samples calculated gold and silver grades ranged from 3.57–13.13 g/t Au and 5.1–21.5 g/t Ag.

Table 10-2: 2018 PFS Testwork Scope

Sample ID

Head Assay

JK drop- weight tests (DWT)

E-GRG

Gravity Separation

Bulk Leach on Gravity Tailing

Cyanide Destruction

Carbon Modelling

Rheology

Solid/ Liquid Separation

Arkose

x

x

—

x

x

x

—

x

x

MLDWT

x

x

—

x

x

x

x

x

x

ML-LG

x

—

x

x

x

—

—

—

—

ML-1

x

—

x

x

x

—

—

—

—

ML-2

x

—

—

x

x

x

—

—

—

HG

x

—

x

x

x

—

—

—

—

SLST

x

—

—

x

x

x

—

x

x

Mudstone

x

—

—

x

x

—

—

—

—

CMB

x

—

—

x

x

x

—

—

—

Note: “x” = test performed; “—” = not performed or not applicable

Table 10-3: Metallurgical Test Matrix for SGS Program 15944-002

Sample ID

Head Assay

Mineralogy Analysis

Comminution BRWi & BBWi

Bottle Roll Leach

Oxygen Uptake

Bulk Leach

Cyanide Destruction

Year 1

x

x

—

x

x

—

—

Year 2

x

—

x

x

x

—

—

Arkose

x

—

x

x

—

—

—

Siltstone

x

—

x

x

—

—

—

Sinter

—

—

x

—

—

—

—

ML-LG

x

—

—

—

—

x

x

Note: “x” = test performed; “—” = not performed or not applicable

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Table 10-4: FS Production Composites Sample Composition

Sample		% Arkose				% Siltstone				% Sinter
Year 1			39.4				44.5				16.0
Year 2			49.4				44.3				6.3

Composites 4551-001 through 4551-006 were designated as Year 1 composites and composites 4551-007 through 4551-012 were designated as Year 2 composites. Year 1 composites were prepared to represent a lithology make-up of 16% sinter, 44.5% siltstone and 39.4% arkose by mass. Year 2 composites were prepared to represent a lithology make-up of 6.3% sinter, 44.3% siltstone and 49.4% arkose by mass as shown in Table 10-4.

A 15 kg master composite sample was generated, designated as 4551-013. This composite was composed of select interval samples used in the variability composites. The lithology make-up of this composite was 6% sinter, 43% siltstone, and 51% arkose by mass.

10.4 Presentation and Discussion of Results

10.4.1 Ore Characterization and Deleterious Elements

Ore composition was investigated in SGS Program 15944-002. Selected head assays are presented in Table 10-5.

Table 10-5: Head Assays

Sample ID		Au (g/t)				Au (oz/ton)				Ag (g/t)				Ag (oz/ton)				Hg (g/t)				ST (%)				S2-S (%)				SO4-S (%)				CT (%)				TOC (%)				Cu (g/t)				Fe (%)				As (g/t)
Year 1			9.56				0.306				12.9				0.413				2.054				0.22				0.08				0.14				0.09				0.09				13.7				0.69				167
Year 2			7.84				0.251				12.5				0.400				2.639				0.44				0.27				0.15				0.12				0.12				15.6				0.92				181
Arkose			9.66				0.309				11.7				0.374				2.066				0.18				0.08				0.1				0.06				0.06				11.6				0.58				119
Siltstone			24.71				0.791				34.2				1.094				2.156				0.42				0.26				0.14				0.35				0.35				15.7				0.93				183
ML-LG			1.69				0.054				8.48				0.271				1.858				0.43				0.25				0.15				0.04				<0.05				36.6				0.84				156

The conclusion of these results is that mercury is present in high enough concentrations to warrant removal and management, and this has been incorporated into the flowsheet. Arsenic is present in the feed at concentrations ranging between 3.47–5.34 oz/ton (119–183 g/t) and is not expected to be problematic in processing. No other elements that may cause issues in the process plant or concerns with product marketability were noted.

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10.4.2 Comminution Test Results

10.4.2.1 Hazen 1990

The historical comminution testwork conducted by Hazen in 1990 and as reported by RDI in 2012 is summarized in Table 10-6.

Table 10-6: Hazen 1990 Comminution Results

Description		Units				Sample Description
						Zone 1				Zone 2				Zone 3				Composite				High Grade
Product Size,80% passing			µm				—				551				483				541				—
Bond rod mill work index, RWI			kWh/ton				—				18.0				17.2				17.6				18.2
Bond ball mill work index, BWI			kWh/ton				—				21.3				17.7				20.2				—
Bond abrasion index, Ai							0.711				0.783				0.529				0.714				—

10.4.2.2 SGS Program 15944-001

JK drop-weight tests (DWT) were conducted on the Arkose Arkose Updated and MLDWT samples. The data were interpreted by JK Tech Pty Ltd (JK Tech) and a summary of results is presented in Table 10-7.

Table 10-7: Summary of JK DWT Results

Sample ID		SG				ta				A				b				Axb
Arkose			2.56				0.13				100				0.32				32.0
MLDWT			2.51				0.15				99.8				0.30				29.9

Note: The JKTech Drop-Weight test provides ore-specific parameters for use in the JKSimMet Mineral Processing Simulator Software.

The t_a parameter indicates resistance to abrasion. The Axb parameter indicates resistance to Impact breakage.

The impact breakage data of these samples showed they can be classified as hard when compared to other samples in the JKTech database. The JK DWT results were used by Ausenco to estimate the crusher work index at 20.9 kWh/ton.

10.4.2.3 SGS Program 15944-002

Bond rod mill work indices are presented in Table 10-8.

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Table 10-8: Bond Rod Mill Grindability Test Results

Sample ID		Mesh of Grind				Work Index (kWh/ton)				Hardness Percentile				Category
Year 2			14				22.2				96			very hard
Arkose			14				19.2				82			hard
Siltstone			14				22.4				97			very hard
Sinter			14				22.5				97			very hard

Bond ball mill work indices are presented in Table 10-8.

Table 10-9: Ball Mill Work Indices

Sample ID		Mesh of Grind				Work Index (kWh/ton)				Hardness Percentile				Category
Year 2			100				26.6				99			very hard
Arkose			100				20.8				88			hard
Siltstone			100				27.3				99			very hard
Sinter			100				32.0				100			very hard

Bond ball mill work indices were performed at a closing screen size of 100 mesh, or 150 µm.

The samples tested were categorized as hard to very hard; this finding aligns with previous findings from historical testwork.

10.4.3  Mineralogical Analysis

10.4.3.1  Hazen 1990

Mineralogical examinations of ore from Zones 1, 2 and 3 showed that they were similar and composed mainly of quartz and orthoclase feldspar. Minor amounts of pyrite were noted, mostly less than 5 µm but ranging up to 20 µm, along with native gold ranging from 50–250 µm in Zones 1 and 3 and up to 600 µm in Zone 2.

10.4.3.2  SGS Program 15944-002

The mineralogical investigation was performed on the Year 1 sample which was stage crushed to a P₈₀ size of 100 mesh (150 µm). A 100 g sample was extracted by riffle splitting for quantitative evaluation of materials by scanning electron microscopy (QEMSCAN) testing and 900 g was submitted for a gold deportment study. The gold deportment subsample was concentrated using gravity methods and examined using the Tescan Integrated Mineral Analyzer (TIMA).

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Findings included:

• Electrum accounts for 77.4% of the total gold grade; the remainder is present as native gold.

• Gold association: The liberation of gold is high at 77.5%. Most of the remainder is associated with light silicates.

• Gold exposure: The exposure of gold (>20% exposure) is good at 89.1%. Gold which is well exposed (>20% exposure) should be readily amenable to leaching.

• Gold association by size and gold mineral sizes: the majority (81%) of gold mineral grains are <30 µm in size, the non-liberated grains typically occur in association with light silicates, complex particles and rarely with oxides, pyrite and silver minerals. Gold grains coarser than 30 µm are liberated. Most gold grains would be leachable.

• Mineral composition is predominantly quartz (63.6%) and K-feldspar (30,7%), with trace amounts (<2%) of clays, sericite/muscovite, plagioclase and other minerals. Pyrite is detected in trace amounts (0.30%). Chalcopyrite and other copper sulfides are present in trace amounts (0.03%).

10.4.4 Leach Tests

10.4.4.1  Evaluation of Grind Size, SGS Program 15944-002

The Year 2 sample was crushed in three stages to -2 mm. A single point grind calibration was conducted on a 1 kg charge in a laboratory rod mill to determine the grind time required to achieve the fineness of grind. A series of standard bottle roll tests were conducted on the Year 2 sample at three grind sizes (P₈₀ of 100 µm, 75 µm and 53 µm ) and two cyanide concentrations (0.5 and 1.0 g/L).

Leaching conditions were a pulp density of 45% solids, pH of 10.5–11 with lime addition and leach time of 24, 48 and 72 hours.

Residue grades decreased with finer grind, for all leach times evaluated.

A P₈₀ grind size of 150 mesh (106 µm) was used in the FS; however, provision to grind finer to 200 mesh (75 µm) was considered in sizing the ball mill.

10.4.4.2  Evaluation of Leach Time, SGS Program 15944-001

A 20 kg sample of each lithology (all nine samples) was ground and passed by a Knelson MD-3 concentrator. The concentrate obtained was further upgraded with a Mozley C800 laboratory separator. The tailings from the Knelson concentrator and Mozley separator were combined and ground to a target P₈₀ size of 150 mesh (106 µm) and submitted for bulk leach testing by CIP or CIL.

For the bulk agitated leach tests, approximately 10 kg of gravity tailings was pulped to 45% solids by weight, pH was adjusted to 10.5–11 with lime, dissolved oxygen (DO) was maintained at >6 ppm, 0.5 g/L of NaCN was added and 0.25 g/L NaCN was maintained throughout the leaching process. Carbon concentrations of 12 g/L and 15 g/L were added for CIL and CIP respectively. The residence times were 48 hours and 72 hours for the CIL and CIP tests respectively. Carbon was added to the pulp at 48 hours for the CIP test. Pre-aeration of three hours was included for both tests.

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Relevant results from SGS Program 15944-001 that align with the selected flowsheet and include samples representative of ore that is included in the 2018 PFS mine plan are shown in Figure 10-1. These results show that gold leaching is fast and complete within 24 hours.

Figure 10-1: Gold Leach Extraction Rate

Source: Ausenco, 2020

10.4.4.3  Evaluation of Leach Time, SGS Program 15944-002

A series of standard bottle roll tests were conducted on the Year 1, Year 2 and Arkose and Siltstone samples at two grind sizes (P₈₀ of 100 µm and 75 µm) and two cyanide concentrations (0.5 and 1.0 g/L).

For each test a 1.0 kg charge was ground to the target grind size and pulped to 45% solids by weight. The pH was adjusted to 10.5–11 using lime and DO was maintained at > 6 mg/L. Three hours of pre-aeration using air were applied to all samples.

A lower level of confidence was placed in these results as the solution assay results were erratic; however, the same trends were seen as in more reliable testwork, i.e. a fast initial leach rate and completion of the gold leach reaction within 24 hours.

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10.4.4.4 Evaluation of Leach Time, McClelland Program MLI 4551

Twelve grade variability composite samples of 1 kg each were prepared for mechanical agitation leach testing. The samples were stage ground to 80% passing 106 µm in a laboratory steel ball mill. Samples were prepared in order of estimated increasing gold grade. Following each composite, the mill was cleaned by grinding barren silica sand.

After grinding, samples were slurried to 45% solids by weight and pH was adjusted to 10.8–11.2 by adding hydrated lime. Slurries were sparged with air for three hours prior to leaching at 0.5 g/L sodium cyanide. Leaching was conducted by mechanically agitating the slurries in baffled, air sparged leaching vessels for 48 hours.

Results are presented in Figure 10-2 and Figure 10-3 and show the gold leach rate flattening by 24 hours, supporting the selection of the leach time at 24 hours.

Figure 10-2: Gold Leach Extraction Rate for Grade Variability Samples

Source: Ausenco, 2020

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Figure 10-3: Silver Leach Extraction Rate for Grade Variability Samples

Source: Ausenco, 2020

McClelland commented that similar dips in the solution grades over time were observed as seen in the SGS program 15944-02 data, and that this is thought to be indicative of the possible presence of preg- Updatedrobbing clays.

10.4.4.5  Effect of Pre-aeration, SGS Program 15944-002

A round of tests were carried out which included a three-hour pre-aeration step ahead of the leach. Tests were conducted at a P₈₀ grind size of 100 µm, 45% solids, pH 10.5–11, and dissolved oxygen maintained at > Retained for consistency with the rest of Section 10 (and others in the report), where the same notation is used7 mg/L for CN3 and >9 Added mg/L for CN9 and CN10 tests.

For tests conducted at 0.5 g/L cyanide addition with and without pre-aeration, cyanide consumption reduced from 0.23 to 0.12 g/t with pre-aeration for the Year 1 sample and from 0.14 to 0.11 g/t for the Year 2 sample. From this investigation it can be concluded that pre-aeration is beneficial to leach kinetics in all cases and to overall recovery, particularly for the Year 2 sample. A three-hour pre-aeration step was incorporated into the plant design.

10.4.4.6  Leach Reagent Consumption, SGS Program 15944-001, SGS Program 15944-002 and McClelland Program MLI 4551

Cyanide and lime consumption rates from all leach tests that included the three-hour pre-aeration step and conducted on relevant lithologies are shown in Table 10-10.

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Table 10-10: Average Cyanide and Lime Consumption

Test Description		Cyanide addition (g/L)				Cyanide Consumption								Lime Consumption
						(kg/t)				(lb/ton)				(kg/t)				(lb/ton)
Bottle roll, PFS			0.5				0.34				0.68				0.84				1.68
Bottle roll, FS			0.5				0.17				0.34				1.27				2.54
Bottle roll, FS			1.0				0.27				0.54				1.27				2.54
Agitated leach, FS			0.5				0.90				1.80				2.74				5.48

A cyanide consumption of 0.34 kg/t and lime consumption of 1.05 kg/t respectively were selected for use in estimating plant operating costs. These values align with the bottle roll test results as these are believed to be a closer representation of plant consumption than the agitated leach tests.

10.4.4.7  Oxygen Uptake Test, SGS Program 15944-02

Two oxygen uptake tests were conducted on each of the Year 1 and Year 2 samples. Samples were ground to a P₈₀ size of 102 µm and pulped to 45% solids with water in a stirred glass reflux reactor at ambient temperature. The sample was agitated with an impeller using a Caframo mixer at 300 rpm throughout the test (~150 rpm for readings). The pulp pH was adjusted to 10.5–11.0 and cyanide was added. Air was sparged into the pulp sample to maintain the dissolved oxygen at a target range of 10–13 mg/L for the first test and 6-8mg/L for the second test. The DO content of the slurry was measured for a total time of 15 minutes, at one-minute intervals. During these readings, the air sparge was removed from the pulp, remaining in the headspace of the vessel. DO readings were taken at 0, 2, 4, 8, 12, 24, 30, and 36 hours.

The test results show that the oxygen uptake rate was very low, showing that the Year 1 and Year 2 samples were low oxygen consumers. Air was selected as the source of oxygen for the plant design.

10.4.4.8  Mercury Dissolution Test, SGS Program 15944-002

Mercury concentrations in the final (48 hour) solutions were 0.25 mg/L and 0.26 mg/L for arkose and siltstone samples, respectively. Mercury analysis in the final (30 hour) solution samples for Year 1 pregnant solutions were 0.16 and 0.25 mg/L for tests with 0.5 and 1.0 g/L of cyanide addition respectively. For Year 2 pregnant solutions, the results were 0.08 and 0.18 mg/L for tests with 0.5 and 1.0 g/L of cyanide addition respectively.

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10.4.5 Cyanide Destruction

10.4.5.1 Historical Results

Cyanide destruction was investigated by SGS (Table 10-11) and acceptable results were achieved relative to the Project design value of <15 mg/L weakly acid dissociable cyanide (CN_WAD).

Table 10-11: Cyanide Destruction Test Results from Historical Work

Test Program		Sample Description		Test		Feed Concentration (CNWAD mg/L)		Product Concentration (CNWAD mg/L)
SGS Program 15944-001		Three lithology samples, continuous tests (MLDWT-CIP, Arkose-CIP, SLST-CIP)		SO2/air		110–149		0.04– 0.10

10.4.5.2  SGS Program 15944-002 Results

A 10 kg bulk cyanide CIP leach test was performed on the ML-LG sample to produce cyanide-leached pulp for cyanide destruction testwork. This sample was selected as it contained sulfide sulfur and iron concentrations representing the upper limits in the Year 1 and 2 samples. The test was conducted in a 20 L pail with an overhead mixer with three hours of pre-aeration. The test conditions were a sample mass of 10 kg, grind size (P₈₀) of 106 µm, pulp density 45% solids, NaCN concentration of 0.5 g/L, pH of 10.5–11 with lime addition, Carbon addition of 15 g/L after 10-hour leach, and a leach time of 48 hours.

Test results are shown in Table 10-12. The test achieved very low levels of CN_WAD (0.13 mg/L) under continuous operation. Reagent addition rates (SO₂, copper sulfate and lime) were typical for this process.

Table 10-12: Cyanide Destruction Test Results – Continuous Test

Test ID		Conditions																Total Continuous Test
		Feed Pulp Volume (L)				Pulp Solids (%w/w)				Feed CNWAD (mg/L)				Test pH				Test DO (mg/L)				Discharge Pulp Volume (L)				Total Run Time (min)				Retention Time (min)				Discharge CNWAD (mg/L)				Discharge CNTotal (mg/L)				Discharge SCN (mg/L)				Discharge CNO (mg/L)				Ratio of SO2- CNWAD (g/g)				SO2 Addition (g/L pulp)				Ratio of Cu- CNWAD (g/g)				Ratio of Lime- CNWAD (g/g)
ML- LG			16.9				40				200				8.6				5.2				14.5				140				51				0.13				0.34				6.9				330				4.23				0.71				0.06				2.1

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10.5 Metallurgical Variability

Metallurgical samples were selected in collaboration with Paramount to represent deposit variability with consideration of:

• spatial variability of the mineralization, shown in Figure 10-4 below;

• composites to investigate effect of feed grade variability over the grade range that occurs within the Mineral Resource; and

• composites to investigate variability due to lithology or rock group.

Figure 10-4: Drill Hole and Interval Locations for Samples in the SGS 2018 and 2020 and McClelland Programs

Source: RESPEC, 2026

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10.5.1.1 2018 PFS Sample Selection

Nine samples were submitted for metallurgical testing. Lithologies were identified by Ausenco, under the guidance of the Paramount technical team. Samples were described as Arkose, MLDWT, Mixed Lithology Low Grade (ML-LG), Mixed Lithology Average Grade (ML-1), Mixed Lithology Average Grade (ML-2), Mixed Lithology High Grade (HG), Silt Stone (SLST), Mudstone and Clay Mixed Breccia (CMB).

Comminution SMC testing (Axb) was carried out on Arkose and Mixed Lithology samples, leach tests were carried out on all samples and continuous cyanide destruction tests were carried out on Arkose, Mixed lithology and Silt Stone samples.

10.5.2 Sample Selection for SGS Program 15944-02

Six composite samples were selected by Paramount with input from Ausenco to represent the production composites for the proposed Year 1 and Year 2 of operations, and the major lithologies, Arkose, Siltstone and Sinter (Table 10-3).

The metallurgical program was performed on composites: Year 1, Year 2, Arkose, Siltstone, Sinter and un-used ML-LG sample from the 2017/2018 testwork program.

Since there was insufficient sample available of the Year 1 composite for comminution testing, it was decided to test the comminution properties for each of the major lithologies for Year 1 as an alternative. A low-grade sinter sample was provided for comminution testing. Comminution testing was performed on Year 2, Arkose, Siltstone and Sinter samples.

Leach testing was performed on Year 1, Year 2, Arkose and Siltstone samples. Cyanide destruction testing was performed on the Mixed Lithology Low Grade sample which was selected as it contained sulfide sulfur and iron concentrations representing the upper limits in the Year 1 and 2 samples.

10.5.3 Sample Selection for McClelland Program MLI 4551

Samples tested at McClelland were made up from drill core as composites to represent the ore that will be mined during the first two years of production. Twelve grade variability composite samples (4551-001 to 012) and one master composite sample (4551-013) were tested. Variability composite samples calculated gold and silver grades ranged from 3.57–13.13 g/t Au and 5.1–21.5 g/t Ag.

Supplementary leach testwork to support recovery estimation was conducted.

10.6 Recovery Estimation

10.6.1 Leach Recovery, SGS Program 15944-001, SGS Program 15944-002 and McClelland Program MLI 4551

The data in Table 10-12 were used as the basis for estimation of recovery for this Report. While the data includes leach tests that ran for longer than the selected leach time of 24 hours, the leach curves shown in Section 10.4 flatten out after 24 hours, giving the same recovery at longer leach times. These data were considered to be sufficiently valid to be included in recovery estimation.

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Table 10-13: Leach Test Data Used for Recovery Estimation

Test Campaign		Test Number		Target Grind Size P80 (µm)		Retention Time (hours)		Leach/ CIL		Leach Feed Source				Cyanide Addition (g/L)				Cyanide held at (g/L)				Leach Feed Grade, Au Calculated (g/t)				Residue Grade, Au (g/t)				Leach Feed Grade, Ag Calculated (g/t)		Residue Grade, Ag (g/t)		Leach Recovery, Au (%)				Leach Recovery, Ag (%)
SGS Program 15944-001		ML1-CIL-A		100		48		CIL			Whole ore				0.5				0.25				4.48				0.36			—		—			91.96			—
		ML1-CIL-B		103		48		CIL			Whole ore				0.5				0.25				4.47				0.69			—		—			84.56			—
		HG-CIL-A		89		48		CIL			Whole ore				0.5				0.25				10.01				0.67			—		—			93.30			—
		ML1-CIL		99		48		CIL			Gravity tailings				0.5				0.25				4.15				0.25			7.67		2.60			93.97			66.11
		ML1-CIL2		104		48		Leach CIP			Gravity tailings				1.0				0.50				4.38				0.35			9.32		3.15			92.01			66.19
		SLST-CIL		114		48		CIL			Gravity tailings				0.5				0.25				3.96				0.25			10.13		2.75			93.69			72.85
		LG-CIL		96		48		CIL			Gravity tailings				0.5				0.25				1.62				0.29			8.41		2.85			82.07			66.11
		HG-CIL		99		48		CIL			Gravity tailings				0.5				0.25				8.88				0.34			15.60		2.40			96.17			84.62
		Arkose-CIL		116		48		CIL			Gravity tailings				0.5				0.25				2.89				0.39			8.17		3.35			86.51			59.00
		MLDWT-CIL		107		48		CIL			Gravity tailings				0.5				0.25				2.47				0.31			7.65		3.00			87.45			60.76
SGS Program 15944-002		Year 1-CN9		98		30		Leach			Whole ore				0.5				0.5				11.29				0.40			14.01		2.80			96.46			80.01
		Year 1-CN10		98		30		Leach			Whole ore				1.0				1.00				11.33				0.37			14.07		2.70			96.73			80.82
		Year 2-CN9		101		30		Leach			Whole ore				0.5				0.5				7.12				0.72			12.30		3.60			89.89			70.72
		Year 2-CN10		101		30		Leach			Whole ore				1				1				7.15				0.51			12.26		2.70			92.87			77.98
		Year 1-CN11		75		30		Leach			Whole ore				0.5				0.5				9.76				0.35			15.00		2.70			96.41			82.00
		Year 2-CN11		74		30		Leach			Whole ore				0.5				0.5				7.10				0.39			15.04		3.20			94.51			78.73
		Year 2-CN12		101		48		Leach			Whole ore				1				1				6.97				0.50			—		—			92.83			—
		Year 2-CN13		74		48		Leach			Whole ore				1				1				6.99				0.42			—		—			93.99			—
		Year 2-CN14		51		48		Leach			Whole ore				1				1				6.94				0.35			—		—			94.96			—
		Arkose-CN1		99		48		Leach			Whole ore				0.5				0.5				11.80				0.51			13.33		2.60			95.68			80.49
		Siltstone-CN1		105		48		Leach			Whole ore				0.5				0.5				17.92				1.18			18.07		2.20			93.42			87.83

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Test Campaign		Test Number				Target Grind Size P80 (µm)				Retention Time (hours)				Leach/ CIL				Leach Feed Source				Cyanide Addition (g/L)				Cyanide held at (g/L)				Leach Feed Grade, Au Calculated (g/t)				Residue Grade, Au (g/t)				Leach Feed Grade, Ag Calculated (g/t)				Residue Grade, Ag (g/t)				Leach Recovery, Au (%)				Leach Recovery, Ag (%)
McClelland Program MLI 4551			AL-7 4551-001				106				48				Leach				Whole ore				0.50				0.50				8.85				0.61				14.6				3.5				93.11				76.03
			AL-9 4551-002				106				48				Leach				Whole ore				0.50				0.50				10.18				0.59				14.6				3.9				94.20				73.29
			AL-5 4551-003				106				48				Leach				Whole ore				0.50				0.50				7.10				0.45				13.5				3.5				93.66				74.07
			AL-3 4551-004				106				48				Leach				Whole ore				0.50				0.50				5.20				0.45				11.1				3				91.35				72.97
			AL-11 4551-005				106				48				Leach				Whole ore				0.50				0.50				11.17				1.19				21.5				4.8				89.35				77.67
			AL-1 4551-006				106				48				Leach				Whole ore				0.50				0.50				3.57				0.37				9.3				2.5				89.64				73.12
			AL-6 4551-007				106				48				Leach				Whole ore				0.50				0.50				8.01				0.47				11				2				94.13				81.82
			AL-10 4551-008				106				48				Leach				Whole ore				0.50				0.50				13.13				0.42				9				1.5				96.80				83.33
			AL-2 4551-009				106				48				Leach				Whole ore				0.50				0.50				4.29				0.23				9.1				2				94.64				78.02
			AL-12 4551-010				106				48				Leach				Whole ore				0.50				0.50				11.02				0.48				9.4				1.7				95.64				81.91
			AL-8 4551-011				106				48				Leach				Whole ore				0.50				0.50				8.75				0.22				13.9				2.4				97.49				82.73
			AL-4 4551-012				106				48				Leach				Whole ore				0.50				0.50				6.21				0.27				5.1				1.1				95.65				78.43

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10.6.1.1 Leach Recovery Estimate

The data in Table 10-12 were used to derive a relationship between leach feed and residue grades for both gold and silver, as shown in Figure 10-4 and Figure 10-5.

Figure 10-5: Relationship Between Leach Feed and Residue Grades for Gold

Source: Ausenco, 2020

Figure 10-6: Relationship Between Leach Feed and Residue Grades for Silver

Source: Ausenco, 2020

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The following relationships were derived from the data in Figure 10-4 and Figure 10-5 to calculate leach gold recovery:

• Leach Residue Grade = 0.0336 (Leach Feed Grade) + 0.2173

• Leach Recovery = (1-leach residue grade/leach feed grade) * 100.

The following relationships were derived from the data in Figure 10-4 and Figure 10-5 to calculate leach silver recovery:

• Leach Residue Grade = 0.112 (Leach Feed Grade) +1.4188

• Leach Recovery = (1-leach residue grade/leach feed grade) * 100.

Predicted leach recovery is compared to recovery achieved in testwork for gold and silver in Figure 10-6 and Figure 10-7, respectively.

Figure 10-7: Predicted versus Measured Recovery for Gold

Source: Ausenco, 2020

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Figure 10-8: Predicted versus Measured Recovery for Silver

Source: Ausenco, 2020

10.6.1.2 Estimation of Plant Losses

Additional plant losses for gold were estimated and are shown in Table 10-14.

Table 10-14: Estimated Additional Plant Losses for Gold

Description		Units		Values
Head Grade		g/t Au		≤6		>6 to ≤ 9		>9
Solution loss		%		0.33		0.35		0.37
Fine carbon loss		%		0.04		0.03		0.03
Other loss plant operation		%		0.10		0.10		0.10
Total additional plant losses		%		0.47		0.49		0.49

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Additional plant losses for silver were estimated and are shown in Table 10-15.

Table 10-15: Estimated Additional Plant Losses for Silver

Description		Units		Value
Solution loss		%		0.33
Fine carbon loss		%		0.06
Other loss plant operation		%		0.10
Total additional plant losses		%		0.49

10.6.1.3 Overall Recovery Estimate

Overall plant recovery for gold and silver is calculated as the leach recovery less the plant losses. Recovery was calculated monthly as a function of head grades for gold and silver based on the feasibility study mine plan.

Mercury has been identified as the only deleterious element of consequences and provisions have been added to the process flowsheet to manage the removal of it from the final product and capture and control it safely.

Arsenic is present in the feed but is not expected to be problematic in processing. No other elements that may cause issues in the process plant or concerns with product marketability were noted.

10.7 Summary

Three recent testwork programs (SGS Program 15944-001, SGS 15944-02 and McClelland MLI 4551) were completed between 2017 and 2020 on samples from the Grassy Mountain deposit to confirm design information and metallurgical response which would provide a basis for process flowsheet selection and recovery estimation.

Between the various recent testwork programs, composite samples representing major lithologies, Year 1 and Year 2 production composites and a range of head grades aligned with the minimum and maximum values expected in the plant feed in the initial two years of production were tested.

The grade variability composite samples calculated gold and silver grades ranged from 0.104–0.383 oz/ton Au (3.57–13.13 g/t Au) and 0.149–0.628 oz/ton Ag (5.1–21.5 g/t Ag).

Comminution testing showed that all the materials tested are considered very hard, with Bond ball mill work indices ranging from 20.8 to 32.0 kWh/ton.

Bottle roll and agitated batch leach tests showed that the samples were highly responsive to recovery by cyanidation at a grind size of 80% passing 150 mesh (106 µm) or lower, with leach recoveries ranging from 82.1–97.5% for gold and 59.0–84.6% 59.0–84.6% Updatedfor silver, dependent on leach feed grade.

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Overall plant recoveries for gold are predicted to range between 89.5 and 94.9% for head grades of 0.096–0.58 oz/ton Au (3.3–17.4 g/t Au) respectively over the life of mine. Overall plant recoveries for silver are predicted to range between 62.7 and 80.4% for head grades of 0.161–0.523 oz/ton Ag (5.5–17.9 g/t Ag) respectively over the LOM.

Cyanide destruction tests achieved <0.2 mg/L CN_WAD, which is well within the maximum legislated value in Oregon of 30 mg/L.

Mercury grades were in the range of 0.054–0.077 oz/ton (1.86–2.64 g/t) in the leach feed, and the concentration of mercury in solution after leaching ranged between 0.08 and 0.26 mg/L. A retort and gas collection and scrubbing system was incorporated into the plant design to manage and control mercury in the process. Arsenic is present in the feed at concentrations ranging between 3.47 and 5.34 oz/ton (119 and 183 g/t) and is not expected to be problematic in processing.

10.8 Qualified Person’s Opinion on Data Adequacy

In the QP’s opinion, based on the testwork summarized in the Report and predictions made from that testwork in terms of mineralogy, plant design considerations, recovery forecasts, and presence of deleterious elements, the predictions of proposed throughput and metallurgical performance are acceptable.

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11 MINERAL RESOURCE ESTIMATES

11.1 Introduction

The qualified person firm RESPEC completed the estimate of mineral resource presented herein.

11.2 Grassy Mountain project Data

RESPEC performed this estimate of the Grassy Mountain project’s mineral resources using data generated by Paramount and the historical operators discussed in Section 7. Paramount provided these data to RESPEC.

11.2.1 Drill-Hole Database

The drill-hole data are in UTM Zone 11 NAD83 coordinates in US Feet. The database includes information from a total of 485 drill holes, 282 of which were drilled in the area of the Grassy Mountain resources. This estimation of the project’s mineral resources directly uses assay data from 256 of these drill holes.

Prior to the 2016–2017 drilling program, Paramount provided RESPEC with a project drill-hole database. As discussed in Section 9.1, RESPEC audited the historical drill data and made corrections as appropriate. RESPEC periodically updated the database with information acquired during Paramount’s subsequent drilling programs, including gold and silver assay data received directly from the analytical laboratory.

11.2.2 Topography

As part of their 2016–2017 work program, Paramount conducted a drone aerial survey over the resource area and collected detailed topographic data. RESPEC used the survey’s raw data to create a three-dimensional digital topographic surface for use in resource modeling.

11.3 Deposit Geology Relevant to Resource Modelling

The Grassy Mountain gold-silver deposit is hosted by arkoses, siltstones, mudstones, and sinters of the Grassy Mountain Formation. As presently drilled, it has extents of 1,900 ft in the strike direction of the higher-grade mineralization (060° to 070°), approximately 2,700 ft perpendicular to the strike, and 1,240 ft in the vertical direction. The deposit is comprised of a high-grade central core zone characterized by gold grades in excess of 0.03 oz/ton Au that lies within a broad envelope of low-grade mineralization. The central core includes mineralization, that is the subject of the economic analysis discussed in the following sections of this feasibility study.

The central core zone extends almost 1,000 ft along strike, about 450 ft perpendicular to strike, and up to 450 ft in the vertical direction. Sub-horizontal and subvertical extensions of the high-grade central-core mineralization extend outward into the low-grade envelope, likely due to stratigraphic and structural controls. The base of the central core is very sharp, marked by a distinct drop in precious-metal grades. It is the lower limit of the strong silicification that typifies the entire Grassy Mountain deposit, including the lower-grade envelope.

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The highest-grade mineralization (>~0.25 oz/ton Au) within the high-grade central core zone and its stratigraphic and structural extensions is most frequently associated with thin (<2 inches), often banded, typically steeply dipping chalcedonic quartz + adularia veins and veinlets. However, there are examples of highest-grade mineralization that have no apparent association with veins. Nor does the presence of veins guarantee high grades. The distribution of the highest-grade mineralization is somewhat erratic, although some systematic distribution is evident. For example, highest-grade mineralization is characteristic of the basal portion of the central core, even as continuity remains limited. In addition, project geologists have hypothesized that the Grassy fault is important in the formation of the deposit. There is evidence of an association between the Grassy fault (and other high-angle structural zones) and higher vein density and grades.

The stratigraphic control of mineralization is expressed by lenses of generally concordant mineralization that extend outwards from the margins of the central core of high-grade mineralization and the low-grade envelope. Similar mineralized lenses are associated with the upper portions of the mineralized structural zones that extend above the central core zone. Mineralization within the central core of the deposit may also have been influenced by the host stratigraphy. Arkose and siltstone are the most common hosts of stratigraphically controlled mineralization, and both sides of the contacts of the interbedded units appear to be particularly favorable.

RESPEC believes the Grassy Mountain gold- and silver-bearing hydrothermal fluids were introduced into the Grassy Mountain Formation along a series of 060°- to 070°-striking, steeply dipping (primarily to the southeast) structural zones that occur over the full extents of the central core of the deposit. Minimal displacement is common across individual structures. The planar base of the deposit and the abrupt change to weakly mineralized and altered rocks below likely reflect the elevation at which boiling in ascending hydrothermal fluids deposited high-grade mineralization. The unfocussed nature of fluid flow along the complex and heavily fractured structural zones resulted in the generally erratic deposition of high-grade mineralization throughout the central core zone.

The waning stages of the mineralizing system appear to be manifested by what Newmont termed “clay matrix breccias.” The breccias are primarily, if not entirely, post-mineral and post-silicification. They are primarily matrix-supported with rotated fragments (some with mineralized quartz veinlets) that range up to boulder-size. Newmont hypothesized that the breccias formed during, “a period of late-stage boiling along pre-existing conduits as H₂S and CO₂ were expelled from the system” (Jory, 1993). Observations of Paramount drill core suggests that the pre-existing conduits are the mineralized structural zones described above. The clay matrix breccias are frequently unconsolidated and have geotechnical implications.

Post-mineral faulting slightly tilted the Grassy Mountain deposit and its host stratigraphy to the east.

RESPEC performed the gold and silver resource modeling within the geological concepts described above.

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11.4 Geologic Modeling

Paramount supplied RESPEC with a set of detailed cross-sectional lithological and structural interpretations that covers most of the extents of the Grassy Mountain mineral deposit. RESPEC used the cross-sections to guide their modeling of the gold and silver mineralization.

The structural interpretations were particularly critical to the modeling of the gold and silver mineral domains discussed in Section 11.7. RESPEC made minor modifications to Paramount’s structural interpretations and modeled additional structures that provide some control for higher-grade mineralization.

11.5 Water Table and Oxidation Modeling

Because oxidation within the Grassy Mountain deposit is variable, accurate modeling of discrete oxide and/or unoxidized zones proved impracticable. The entire deposit is characterized as mixed oxidized, partially oxidized, and unoxidized material, although the unoxidized portions typically occurring only locally.

Hydrologic conditions are discussed in Section 13.3. Other than potential impacts of down-hole contamination in RC drill holes (discussed in Section 7.4.2), the presence or absence of groundwater did not impact the resource modeling.

11.6 Density Modeling

In 1990, Hazen Research, Inc. (Hazen) completed 314 measurements of bulk density. In addition, Atlas collected 61 bulk density measurements. Hazen determined bulk density using the water-immersion method on samples of drill core. RESPEC does not know if Hazen wax-coated the samples with open spaces. The samples were categorized by gold grade ranges, but the specific drill intervals tested are not known. Table 11-1 summarizes the Hazen densities (tonnage factors are presented in ft³/ton).

Table 11-1: Hazen Research, Inc. tonnage Factors

Zone		Mean		Median		Min		Max		Count		Grade Range (oz/ton Au)
OZ-1		12.8		12.8		13.7		12.3		63		<0.005
OZ-2		12.8		12.8		14.4		12.3		166		0.003–0.050
OZ-3		13.1		13.0		24.6		11.0		85		0.050–0.750

The Atlas completed their 61 bulk density determinations at their Gold Bar mine in Nevada. Steele (1990) described their methodologies as “wet tests.” The same memorandum described the Hazen procedures as “wet and dry.” Based on these descriptions, RESPEC believes that Atlas tests were performed using the water-displacement method. However, RESPEC cannot confirm the exact methods employed. The drill-core samples tested by Atlas are identified by drill interval, and their spatial locations within the deposit are known.

Newmont density tested 10 samples of drill core (Jory, 1993). Although the test results are not available, Jory (1993) stated that the results suggest “a Grassy Mountain tonnage factor closer to 13.3 ft³/ton.”

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Paramount requested ALS complete bulk-density testing on 266 samples of core from the Atlas, Calico, and Newmont drilling programs and 374 samples of core from Paramount’s 2016–2017 drill program. ALS made the determinations using the water-immersion method (ALS codes OA-GRA08). Coating with paraffin wax was implemented when necessary (OA-GRA08A). Two of the sinter density determinations were anomalously high (low tonnage factors), and RESPEC removed them from the dataset.

RESPEC examined the density data collected by Atlas and Paramount collectively and individually by rock types and gold domains. In general, average tonnage factors from the Atlas data for the lithological and grade subgroups are slightly lower (higher density) than those determined by Paramount. Table 11-2 summarizes the combined Atlas and Paramount dataset grouped by modeled gold domain. The assay range for the low-grade gold domain (100) is ~0.006 to ~0.030 oz/ton Au, and the high-grade domain consists of assays > ~0.030 oz/ton Au.

Table 11-2: Combined Atlas and Paramount tonnage Factors

Gold Domain		Mean		Median		Min		Max		Count		Block Model
100		13.3		13.0		21.5		11.6		341		13.5
200		13.0		12.9		14.7		12.4		275		13.5
100+200		13.2		12.9		21.5		11.6		616		n/a
0		14.8		14.5		23.0		11.2		83		14.8

Inclusive of the Hazen tests, the results indicate that the density associated with the Grassy Mountain mineralization is consistent. Unmineralized rocks are distinctly less dense. This is likely a reflection of the strong silicification associated with all grades of mineralization. Unmineralized rocks have weaker silification or else lack it entirely.

RESPEC used the block model tonnage factors shown in Table 11-2 in the estimation of mineral resources. The tonnage factors applied to mineralized material in the block model are slightly higher (lower density) than the measured mean values from core to account for voids related to the relatively high degree of fracturing in the Grassy Mountain deposit.

11.7 Gold and Silver Modeling

11.7.1 Mineral Domains

A mineral domain encompasses a volume of rock that ideally is characterized by a single natural grade population of a metal or metals that occurs within a specific geologic environment. To define the mineral domains at Grassy Mountain, RESPEC identified the natural gold and silver populations by plotting all drill-hole assays on population-distribution graphs. Some distribution plots used only core sample analyses. The analysis identified three grade populations each for gold and silver. However, the highest-grade populations of gold (>~0.25 oz/ton Au) and silver (>~0.4 oz/ton Ag) do not have sufficient continuity for confident modeling of the domain. Therefore, RESPEC did not explicitly model these populations. Table 11-3 lists the approximate grade ranges of modeled gold and silver lower-grade (domain 100) and higher-grade (domain 200) domains.

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Table 11-3: Approximate Grade Ranges of Gold and Silver Domains

Domain		oz/ton Au		oz/ton Ag
100		~0.006 to ~0.03		~0.04 to ~0.15
200		> ~0.03		> ~0.15

To model the gold and silver mineralization, RESPEC first interpreted gold and silver mineral-domain polygons individually on a set of vertical, 50-ft spaced cross-sections looking northeast to azimuth 070° that span the extent of the deposit, then interpreted the mineral domains using the gold and silver drill-hole assay data, associated alteration and mineralization codes, and Paramount’s sectional lithological and structural interpretations. During the sectional modeling, RESPEC extensively referred to core photographs, used them to discern the stratigraphic and structural controls of mineralization discussed in Section 11.3 and modeled the domains accordingly. First, RESPEC modeled gold, then used the sectional gold-domain polygons to guide the silver domain modeling.

Due to the inherent variability of the Grassy Mountain mineralization, some of the high-grade domains (domain 200) included significant quantities of low-grade mineralization. This variability precluded confident modeling of the highest-grade gold and silver population, and RESPEC did not define the mineralization separately from the high-grade gold and silver domains. From core observations, the highest-grade gold population (>~0.25 oz/ton Au) strongly correlates with the presence of thin, often banded, quartz–chalcedony veins and veinlets and/or breccias. Visible gold is sometimes present. Most commonly, the high-grade veinlets are steeply dipping—as assessed from drill-hole orientations and angles to core axes.

Although the grade change across the boundary between the low– and high-grade domains is usually sharp, it is locally gradational. Commonly, the grade change across the sub-horizontal base of the high-grade domain is very abrupt, particularly in core holes, and is marked by a significant decrease in the intensity of silicification.

The mineralization in the low-grade domain is much less variable than the higher-grade mineralization. This mineralization is distal from the zone of boiling and related brecciation, and its distribution exhibits strong stratigraphic controls.

RESPEC pressed the cross-sectional gold and silver mineral-domain envelopes horizontally to the drill data within each sectional window and sliced them at 10-ft vertical intervals to match the mid-bench elevations of the block model, then used these slices to create gold and silver mineral-domain polygons on 10-ft spaced level plans at mid-block locations. Slices of triangulated surfaces of the steeply dipping structures that influence the distribution of higher-grade mineralized zones guided the level plan interpretations.

Figure 11-1 to Source: RESPEC, 2026

Figure 11-4 provide cross-sections showing geology and gold and silver mineral domains in the central portion of the Grassy Mountain deposit.

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Figure 11-1: Cross-section 3050 Showing Geology and Gold Domains

Source: RESPEC, 2026

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Figure 11-2: Cross-section 3050 Showing Geology and Silver Domains

Source: RESPEC, 2026

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Figure 11-3: Cross-section 3250 Showing Geology and Gold Domains

Source: RESPEC, 2026

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Figure 11-4: Cross-section 3250 Showing Geology and Silver Domains

Source: RESPEC, 2026

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11.7.2 Assay Coding, Capping, and Compositing

To code the drill-hole samples, RESPEC used the cross-sectional gold and silver mineral domain polygons and determined assay caps by inspecting the population distribution plots of the coded assays, by domain, and identifying high-grade outliers appropriate for capping (Table 11-4). In the definition of the assay caps, RESPEC also considered descriptive statistics of the coded assays by domain, visually reviewed the spatial relationships of the possible outliers and evaluated their potential impacts during grade interpolation. The number of samples subjected to capping and the chosen capping grades were minimized because of the application of search restrictions described in Section 11.7.4.

Table 11-4: Grassy Mountain Gold and Silver Assay Caps by Domain

Domain		oz/ton Au		Number Capped (% of Samples)		oz/ton Ag		Number Capped (% of Samples)
0		0.090		8(<1%)		0.120		12(<1%)
100		0.300		3(<1%)		0.600		4(<1%)
200		10.000		4(<1%)		7.000		2(<1%).

In addition to the low- and high-grade domain capping, RESPEC assigned samples outside the modeled domains as Domain 0 and capped them as shown in Table 11-4. Table 11-5 and Table 11-6 provide descriptive statistics of the capped and uncapped coded gold and silver assays.

Table 11-5: Descriptive Statistics of Grassy Mountain Coded Gold Assays

Domains		Assays		Count		Mean (oz/ton Au)		Median (oz/ton Au)		Std. Dev.		CV		Min (oz/ton Au)		Max (oz/ton Au)
0		Au		23,361		0.002		0.001		0.007		3.45		0.000		0.732
		Au Cap		23,361		0.002		0.001		0.004		2.15		0.000		0.090
100		Au		24,808		0.013		0.011		0.011		0.82		0.000		0.561
		Au Cap		24,808		0.013		0.011		0.010		0.77		0.000		0.300
200		Au		7,523		0.108		0.044		0.441		4.09		0.000		21.698
		Au Cap		7,523		0.107		0.044		0.405		3.79		0.000		10.000
100+200		Au		32,331		0.033		0.013		0.209		6.27		0.000		21.698
		Au Cap		32,331		0.033		0.013		0.193		5.81		0.000		10.000

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Table 11-6: Descriptive Statistics of Grassy Mountain Coded Silver Assays

Domains		Assays		Count		Mean (oz/ton Ag)		Median (oz/ton Ag)		Std. Dev.		CV		Min (oz/ton Ag)		Max (oz/ton Ag)
0		Ag		20,921		0.009		0.005		0.011		1.19		0.000		0.496
		Ag Cap		20,921		0.009		0.005		0.010		1.11		0.000		0.120
100		Ag		13,292		0.071		0.064		0.040		0.57		0.003		1.138
		Ag Cap		13,292		0.071		0.064		0.039		0.55		0.003		0.600
200		Ag		6,646		0.262		0.200		0.400		1.52		0.005		18.600
		Ag Cap		6,646		0.260		0.200		0.310		1.19		0.005		7.000
100+200		Ag		19,938		0.132		0.085		0.246		1.86		0.003		18.600
		Ag Cap		19,938		0.131		0.085		0.199		1.51		0.003		7.000

RESPEC composited the capped assays to 5-ft down-hole intervals that respected the mineral domain boundaries. The 5-ft composite length is equal to the sample length of RC drill samples. To retain the inherent variability of the Grassy Mountain mineralization in the resource modeling, RESPEC minimized the compositing and did not apply a shorter composite length to avoid decomposition the majority of the assay samples. Descriptive statistics of Grassy Mountain composites are shown in Table 11-7 for gold and

Table 11-8 for silver.

Table 11-7: Descriptive Statistics of Grassy Mountain Gold Composites

Domain		Count		Mean (oz/ton Au)		Median (oz/ton Au)		Std. Dev.		CV		Min (oz/ton Au)		Max (oz/ton Au)
0		23,452		0.00		0.00		0.00		2.15		0.00		0.09
100		24,213		0.01		0.01		0.01		0.74		0.00		0.30
200		6,738		0.11		0.05		0.35		3.30		0.00		9.89
100+200		30,951		0.03		0.01		0.17		5.09		0.00		9.89

Table 11-8: Descriptive Statistics of Grassy Mountain Silver Composites

Domain		Count		Mean (oz/ton Ag)		Median (oz/ton Ag)		Std. Dev.		CV		Min (oz/ton Ag)		Max (oz/ton Ag)
0		20,910		0.009		0.005		0.010		1.100		0.000		0.120
100		12,985		0.071		0.067		0.038		0.530		0.003		0.600
200		6,137		0.260		0.200		0.295		1.140		0.005		7.000
100+200		19,122		0.131		0.085		0.191		1.460		0.003		7.000

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11.7.3 Block Model Coding

RESPEC used level-plan mineral-domain polygons to code a three-dimensional block model comprised of 5 ft x 10 ft x 10 ft blocks (model x, y, z) with a model bearing of 340°. RESPEC chose the block size most appropriate for the underground mining scenario evaluated in this feasibility study.

Using the midblock level plan polygons, RESPEC coded the volume percentage of each of the two gold and silver domains into each model block, calculated the partial percentages of the model blocks that are partially or entirely outside the low- and high-grade domains, and stored the volume percentages of the gold and silver mineral domains within each block. RESPEC also coded the block model using the digital topographic surface described in Section 11.2.2.

Employing the bulk density values discussed in Section 11.6, RESPEC assigned values so that blocks coded with any partial percentage of gold or silver have a density of 13.5 ft³/ton, and entered a value of 14.8 ft³/ton all other blocks.

11.7.4 Grade Interpolation

Table 11-9 summarizes the parameters applied to the gold-grade estimations at Grassy Mountain. RESPEC completed the grade interpolation in three passes using length-weighted composites within two estimation areas. Estimation area 10 dips shallowly at about -15° and encompasses most of the stratigraphically controlled mineralization in the Grassy Mountain deposit. Estimation area 20 is comprised of mineralization in the west–southwestern portion of the deposit where the dips of the stratigraphic units steepen to approximately -20°. As Table 11-9 shows, the low-grade gold and silver domains and the areas outside modeled domains were entirely estimated using search ellipses that reflect these stratigraphic orientations.

The high-grade gold and silver domains exhibit both sub-horizontal (stratigraphic) and high-angle (structural) controls. To prioritize estimation of the highest-grade mineralization—which is most commonly associated with steeply dipping veinlets—the first estimation pass of the high-grade domain reflects high-angle structural controls (Table 11-9, estimation area 10, domain 200, pass 1). The second estimation pass of the high-grade domain applied a search ellipse reflective of stratigraphic control using the same search distance as pass 1 (50 ft). The second pass did not overwrite blocks with grades estimated during pass 1. The third and final estimation pass was an isotropic pass without either a structural or stratigraphic bias. It was used to estimate domain 200 grades into blocks in the outer extents of the domain that were not estimated by the first two passes.

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Table 11-9: Estimation Parameters

Estimation Pass – Au + Ag Domain		Search Ranges (ft)						Composite Constraints
		Major		Semi-Major		Minor		Min		Max		Max/Hole
Pass 1 – Domain 0 + 100		100		100		50		2		15		3
Pass 2 – Domain 0 + 100		200		200		100		2		15		3
Pass 3 – Domain 0 + 100		310		310		310		1		15		3
Pass 1 + 2 – Domain 200		50		50		16.7		2		15		3
Pass 3 – Domain 200		110		110		110		1		15		3
Restrictions on Search Ranges
Domain		Grade Threshold		Search Restriction Distance								Estimation Pass
Au 200		>0.30 oz/ton Au		35 ft								2
Au 0		>0.01 oz/ton Au		30 ft								1, 2, 3
Ag 0		>0.04 oz/ton Ag		30 ft								1, 2, 3

Search Ellipse Orientations

Estimation Area

Au + Ag Domains and Controls

Major Bearing

Plunge

Tilt

Estimation Pass

10 [Most of the Deposit]

Domain 0 + 100 – Stratigraphic

0°

0°

-15°

1, 2, 3

Domain 200 –Structural

070°

0°

-85°

1

Domain 200 – Stratigraphic

070°

-10°

0°

2

Domain 200 – Stratigraphic

0°

0°

0°

3

20 [WSW End of the Deposit]

Domain 0 + 100 + 200 – Stratigraphic

070°

0°

20°

1, 2, 3

Only a very limited portion of the high-grade gold and silver domains lie in estimation area 20.

Statistical analyses of coded assays and composites, including coefficients of variation and population-distribution plots, indicate that the high-grade gold and silver domains capture multiple populations. RESPEC restricted the search distances because these multiple populations lack sufficient continuity to be explicitly modeled as separate domains and the initial estimation runs without the restrictions resulted in unrealistic volumes and unrealistic distribution of high grades in the block model. The search restrictions limit the distance from a given composite above a chosen gold or silver grade that can be used in grade interpolation. RESPEC finalized the search-restriction grades and distances after running multiple interpolation iterations to test the effects of various search-restriction parameters.

RESPEC interpolated gold and silver grades using inverse-distance to the third power (ID3), ordinary-kriging (OK), and nearest-neighbor (NN) methods and reported this estimate of mineral resources using the ID3 interpolations because ID3 produced results more representative of the geology and distribution of drill-hole assay data than those obtained by OK. To check the ID3 and OK interpolations, RESPEC completed the NN estimation.

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RESPEC performed the estimation passes independently for each of the mineral domains only using composites coded to a particular domain to estimate grade into blocks coded by that domain. To enable the calculation of weight-averaged gold and silver grades for each block, RESPEC coupled the estimated grades with the partial percentages of their respective mineral domains and the outside-domain volumes. Therefore, the final resource grades, and their associated resource tonnages, are fully block-diluted.

11.7.5 Model Checks

To assure close agreement, RESPEC compared gold and silver domain volumes coded into the block model as partial percentages to the volumes of both the cross-sectional and level-plan mineral-domain polygons, visually checked all block-model coding, and used a polygonal estimate that used the cross-sectional domain polygons to check the ID3 estimation results and the NN and OK estimates. The checks identified no unexpected relationships between the check estimates and the inverse-distance estimate. To check both the global and local estimation results, RESPEC evaluated various grade-distribution plots of assays, composites, and NN, OK, and ID3 block grades. Finally, RESPEC visually compared the ID3 grades to the drill-hole assay data in detail to assure that reasonable results were obtained, placing particular emphasis on the evaluation of the distribution and tenor of the high-grade gold and silver estimates.

11.8 Grassy Mountain Mineral Resources

11.8.1 Pit Optimizations, Cutoff Grades and Reporting Prices

The Grassy Mountain deposit has the potential to be mined by open-pit methods. While the mineral reserves discussed in Section 12 are estimated on the basis of a proposed underground-mining scenario, these mineral reserves represent only a small subset of the entire Grassy Mountain gold–silver deposit. The reported mineral resources reflect potential open-pit extraction and milling as the primary scenario (mineral resources potentially amenable to open pit mining methods), with the potential underground mining of a very small quantity of material lying outside of the lower portions of the open pit as a secondary scenario (mineral resources potentially amenable to underground mining methods). The mineral reserves discussed in Section 12 were converted primarily from the potential open-pit resources, with a small amount converted from the underground resource estimate.

To meet the requirement of reasonable prospects for eventual economic extraction for the portion of the mineral resources potentially amenable to open pit mining methods, RESPEC ran a pit optimization using the parameters summarized in Table 11-10.

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Table 11-10: Pit Optimization Parameters

Item		Value				Unit
Mining Cost			3.14			$/ton
Processing Cost			16.33			$/ton processed
Process Rate			5,000			tons-per-day processed
General and Administrative (G&A) Cost			2.79			$/ton processed
Au Price			3,100			$/oz
Ag Price			34			$/oz
Au Recovery			80			Percent
Ag Recovery			60			Percent
Royalty			1.5%			NSR
Au Refining Cost			5.00			$/oz produced
Ag Refining Cost			0.50			$/oz produced

RESPEC used the pit shell created by this optimization to constrain the mineral resources potentially amenable to open-pit mining methods, with the added constraint of a gold-equivalent cut-off grade of 0.008 oz/ton AuEq applied to all model blocks lying within the optimized pit. RESPEC calculated the gold-equivalent cut-off grade using the processing and general and administrative costs and the gold price, recovery, refining cost, and royalty provided in Table 11-10. The mining cost is not included in the determination of the applied internal cut-off grade because all material will potentially be removed from the conceptual pit and the cut-off grade is applied only to the decision to send the mined materials for processing or to the waste-rock storage facilities. Therefore, the reference point at which the mineral resources are defined is at the top of the pit, where material equal to or greater than the cut-off grade would be processed.

The gold equivalent grade (oz/ton AuEq) of each model block was calculated as follows:

oz/ton AuEq = oz/ton Au + (oz/ton Ag ÷ 129)

The silver-to-gold equivalency factor of 129 was derived from the metal prices and recoveries in Table 11-10.

The metal prices used in the pit optimization and the determination of the gold-equivalent cut-off grade and gold-equivalency factor were $3,100/oz for gold and $34/oz for silver. RESPEC chose the metal prices based on consensus commodity price forecasts in March 2026 and on prices used to report resources recently filed on SEDAR. When this mineral resource estimate was completed, several recently filed technical reports provided resources at gold prices between $2,500 and $3,100/oz Au, the spot price for gold was over $4,500/oz Au, and the three-year moving-average price was about $2,835/oz Au and rising. The spot price for silver was over $60/oz Ag, and the three-year moving-average price was about $36/oz Ag and rising.

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To estimate mineral resources potentially amenable to underground mining methods, RESPEC applied a cut-off of 0.070 oz/ton AuEq to blocks lying immediately outside of the optimized pit that could reasonably be accessed from the resource pit. Table 11-11 lists the parameters used to calculate the underground cut-off grade. The parameters used to estimate the very limited quantity of resources lying outside of the resource pit potentially amenable to underground extraction (less than 500 oz Au) are derived from, but more optimistic than, those used to define the mineral reserves discussed in Section 12.

Table 11-11: Parameters Used to Determine Cut-Off Grade for Mineral Resources Potentially Amenable to Underground Mining Methods

Item		Value		Unit
Mining Cost		141.77		$/ton
Processing Cost		39.09		$0/ton processed
Process Rate		5,000		tons-per-day processed
General and Administrative Cost		20.15		$/ton processed
Au Price		3,100		$/oz
Ag Price		34		$/oz
Royalty		1.5%		NSR
AuEq Recovery		92.8		Percent
Refining Cost		7.22		$/oz produced

RESPEC based both the open-pit and underground resource estimates on a 5,000-tons-per-day processing rate, with processing assumed to consist of crushing and milling followed by CIL recovery.

11.8.2 Mineral Resources

The Grassy Mountain mineral resources exclusive of the resources that have been converted to mineral reserves are presented in Table 11-12. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

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Table 11-12: Grassy Mountain Gold and Silver Resources – Exclusive of Mineral Reserves

		Resources												Cut-off Grades (oz/ ton Au)				Metallurgical Recovery
		Amount (tons)				Grades
						oz/ton Au				oz/ton Ag
Measured Mineral Resources			33,700,000				0.015				0.061				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %
Indicated Mineral Resources			21,887,000				0.021				0.081				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %
Measured + Indicated Mineral Resources			55,587,000				0.017				0.069				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %
Inferred Mineral Resources			3,779,000				0.019				0.056				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %

Notes:

• RESPEC is the qualified person firm responsible for the mineral resources estimate.

• Mineral resources are comprised of all model blocks at a 0.008 oz/ton AuEq cut-off that lie within an optimized pit plus blocks at a 0.070 oz/ton AuEq cut-off that lie outside of the optimized pit.

• oz/ton AuEq (gold equivalent grade) = oz/ton Au + (oz/ton Ag ÷ 129).

• Mineral resources summarized in the table immediately above are reported exclusive of the mineral resources converted to mineral reserves. Mineral resources that are not mineral reserves do not have demonstrated economic viability.

• Mineral resources potentially amenable to open pit mining methods are reported using a gold price of $3,100/oz, a silver price of $34/oz, a throughput rate of 5,000 tons/day, assumed metallurgical recoveries of 80% for Au and 60% for Ag, mining costs of $3.14/ton mined, processing costs of $16.33/ton processed, general and administrative costs of $2.79/ton processed, and refining costs of $5.00/oz Au and $0.50/oz Ag produced. Mineral resources potentially amenable to underground mining methods are reported using a gold price of $3,100/oz, a silver price of $34/oz, a throughput rate of 5,000 tons/day, assumed metallurgical recoveries of 92.8% gold equivalent, mining costs of $141.77/ton mined, processing costs of $39.09/ton processed, general and administrative costs of $20.15/ton processed, and refining costs of $5.00/oz gold equivalent produced.

• The effective date of the mineral resources estimate is February 28, 2026, and the effective date of the database on which the Mineral Resources estimate is based is May 1, 2018;

• Rounding may result in apparent discrepancies between tons, grade, and contained metal content.

The mineral resources exclusive of mineral reserves contain 490,000 oz of gold and 2,065,000 oz of silver classified as measured, 462,000 oz of gold and 1,777,000 oz of silver classified as indicated, and 73,000 oz of gold and 210,000 oz of silver classified as inferred.

The Grassy Mountain project mineral resources inclusive of the resources that have been converted to mineral reserves are summarized in Table 11-13.

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Table 11-13: Grassy Mountain Gold and Silver Resources – Inclusive of Mineral Reserves

		Resources												Cut-off Grades (oz/ton Au)				Metallurgical Recovery
		Amount (tons)				Grades
						oz/ton Au				oz/ton Ag
Measured Mineral Resources			33,999,000				0.016				0.063				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %
Indicated Mineral Resources			23,795,000				0.034				0.098				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %
Measured + Indicated Mineral Resources			57,794,000				0.023				0.077				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %
Inferred Mineral Resources			3,779,000				0.019				0.056				Inside Pit: 0.008 Outside Pit: 0.07				Au – 80 Ag – 60	%  %

Note: Footnotes to Table 11-12 are also applicable to this table, with the exception that the mineral resources summarized in the table immediately above are inclusive of the resources that have been converted to mineral reserves. This table is not additive to Table 11-12.

The mineral resources inclusive of mineral reserves contain 540,000 oz of gold and 2,142,000 oz of silver classified as measured, 817,000 oz of gold and 2,325,000 oz of silver classified as indicated, and 73,000 oz of gold and 210,000 oz of silver classified as inferred.

As of the effective date, RESPEC is not aware of any unusual environmental, permitting, legal, title, taxation, socio-economic, marketing, political, or other relevant factors not discussed in this feasibility study that could materially affect the mineral resource estimates.

Figure 11-5 through Figure 11-8 are cross-sections through the central portion of the Grassy Mountain deposit that show estimated block-model gold and silver grades. These figures correspond to the mineral-domain cross-sections presented in Figure 11-1 to Figure 11-4.

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Figure 11-5: Cross-section 3050 Showing Block-Model Gold Grades

Source: RESPEC, 2026

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Figure 11-6: Cross-section 3050 Showing Block-Model Silver Grades

Source: RESPEC, 2026

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Figure 11-7: Cross-section 3250 Showing Block-Model Gold Grades

Source: RESPEC, 2026

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Figure 11-8: Cross-section 3250 Showing Block-Model Silver Grades

Source: RESPEC, 2026

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11.8.3 Classification

Uncertainties that impact resource classification at Grassy Mountain include: (i) the preponderance of vertical RC holes drilled by historical operators; (ii) the potential for poor sample quality in some portions of the RC holes; and (iii) the adequacy of the drill-hole spacing in the higher-grade core of the deposit, where the definition of structural controls on higher-grade mineralization is critical and variability in the highest-grade gold population is high.

Atlas drilled 180 of the 256 holes that contributed data to the grade estimation of the current mineral resources. All but four of Atlas’s holes were drilled vertically, and only nine of Atlas’s holes were core. Due to the emerging understanding of the importance of high-angle structural controls to the higher-grade mineralization, all operators after Atlas, including Paramount, emphasized angled core holes in their drilling programs. A total of 59 core holes, including 27 drilled by Paramount, and 55 angled RC and core holes, including 18 drilled by Paramount, support the current resource estimates, almost all of them drilled within the central, higher-grade core of the deposit. This post-Atlas drilling, and particularly the Paramount program planned in coordination with RESPEC, significantly enhanced RESPEC’s confidence in the geological understanding of the Grassy Mountain deposit and decreased uncertainties in the resource estimation related to the relative lack of angled core holes in the historical drilling.

There is an inherent risk of down-hole contamination in RC drilling, particularly below the water table. RESPEC identified 21 RC holes with suspected intervals of down-hole contamination, all within the deepest portion of the central core of the deposit where groundwater was encountered in drilling. The samples from these intervals were excluded from use in the resource estimation.

The central, higher-grade core of the deposit—which is critical to the potential economic viability of any mining operation at Grassy Mountain—has predominantly been drilled at hole spacings of about 30 to 50 ft. Even at this tight drill spacing, in many cases the highest-grade gold mineralization (>~0.2 oz/ton Au) could not be confidently correlated from drill hole to drill hole. Because the highest-grade population could not be confidently modeled as its own mineral domain, these high-grade samples were included in domain 200, which encompassed grades greater than approximately 0.03 oz/ton Au. While RESPEC took special care to properly represent the highest-grade population within this domain during grade estimation, its inclusion within the domain creates increased grade variability and adds uncertainties.

The risk imparted by the variability of the highest-grade gold mineralization influenced the choice of estimation parameters applied to mineral domain 200 (Table 11-9), including: (i) the use of a tight search ellipse (3:1 ratio of major and semi-major axes to the minor axis); (ii) limiting the search distances of estimation pass 1 and pass 2 to a maximum of 50 ft (which still resulted in only a small proportion of the model blocks in the core zone of the deposit to be estimated in pass 3); and (iii) a further restriction on the search distance in pass 2 that limits the influence of composites grading in excess of 0.3 oz/ton Au to 35 ft. (Pass 2 estimates grade respecting subhorizontal lithologic controls.)

In consideration of the uncertainties discussed above and the steps taken to mitigate these uncertainties, the most significant risk that remains in the current Grassy Mountain mineral resource estimation is related to the modeling of the highest-grade gold mineralization in the central core of the deposit. While visual and statistical evaluations give RESPEC confidence that the volume of the modeled highest-grade population properly respects its proportional representation as defined by the unclustered drill data, the modeled locations of these grades in the block model likely vary from reality as distances from the drill data increase.

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RESPEC classified the Grassy Mountain mineral resources according to the criteria presented in Table 11-14 and applied the criteria to the estimation of gold grades because gold is much more economically significant than silver.

Table 11-14: Resource Classification Parameters

Class		Criteria		Distance of Block Centroid to Nearest Composite
Measured		All estimated blocks coded to Au Domain 200 with or without Au Domain 100 coding		< 10 ft
		All estimated blocks coded exclusively to Au Domain 100		< 50 ft
Indicated		All estimated blocks coded to Au Domain 200 with or without Au Domain 100 coding not classified as measured		< 50 ft
		All estimated blocks coded exclusively to Au Domain 100 not classified as measured		< 100 ft
Inferred		All other estimated blocks

Considering the preceding discussion related to uncertainties in the resource modeling, RESPEC used two sets of criteria in the definition of measured and indicated classifications of the resource model blocks. RESPEC applied one set of more restrictive parameters to all blocks coded as having any percentage of gold domain 200 (the high-grade domain), and another, less restrictive set of criteria to all other blocks which are coded entirely to domain 100 (the lower-grade gold domain). Domain 200 includes the central core zone of the deposit and thin, structurally and stratigraphically controlled mineralization that extends outward from the core zone. Domain 100 is comprised of the much larger, lower-grade halo of mineralization that encompasses domain 200. Domain 100 mineralization has much more extensive grade continuity and is less influenced by discreet structural controls. Therefore, the distance criteria required in domain 100 for measured and indicated classifications are significantly less restrictive than those applied to blocks coded to domain 200.

Despite the relatively restricted distances of measured and indicated blocks from the drill data used to estimate grades, the tight drill spacing that characterizes the deposit significantly limits the quantity of inferred material.

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11.9 Additional Comments on the Modeling of the Mineral Resources

RESPEC estimated the current Grassy Mountain mineral resources in consideration of potential mining by open pit methods and a very minor amount of potential underground-mineable resources that lie immediately outside of the pit walls. However, an alternate scenario is also realistic, whereby only the higher-grade portion of the deposit is mined exclusively by underground methods. This latter scenario was chosen to define the mineral reserves discussed in Section 12. RESPEC constructed the resource model to accommodate both potential open-pit and underground mining scenarios. The 5 x 5 x 10 ft block size fits seamlessly with the reserve stope optimization discussed in Section 12, while the blocks could easily be re-blocked to a larger size (e.g., 20 x 20 x 20 ft) to accommodate open-pit engineering requirements. All other modeling steps and inputs RESPEC used to estimate the Au and Ag resources—including the mineral-domain modeling, grade capping, compositing, grade estimation, density assignment, and classification—were completed independent of potential mining method.

As previously discussed, during resource modeling RESPEC identified structural zones as the principal controls of the high-grade mineralization within the central core of the Grassy Mountain deposit. This structurally controlled mineralization has significant grade variability, which creates modeling uncertainties with respect to the location of the estimated high grades as distances from drill data increase. While the risk imparted by the location uncertainty would be low in an open-pit mining scenario, underground mining requires far greater spatial accuracy. The current model is not sufficiently precise for use in underground mining. To properly inform an underground mining operation’s short- and long-term resource models and refine geotechnical modeling and final stope designs, the central core of the Grassy Mountain deposit would require properly oriented, closely spaced definition drilling. In the short term, RESPEC strongly recommends drilling from the surface prior to mining to reduce the uncertainties in the high-grade mineralization model. Drilling on tighter spacing for more precise delineation of the high-grade mineralization and stope design would take place from underground. Additional drilling would also be important from a geotechnical standpoint, again primarily to inform an underground mining operation, because the mineralized structures are typically characterized by poor to very poor rock quality.

There are 14,947 sample intervals in the drill-hole database that have gold assays but no silver analyses. In most cases, entire drill holes were not assayed for silver. For example, some of the early Atlas holes and all the Newmont holes were not assayed for silver. A total of 4,720 of the sample intervals lacking silver assays lie within the domains that form the basis of the gold and silver resource estimates, while 19,938 sample intervals used in the resource estimates do have silver analyses. The effect of the lower quantity of silver analyses on the resource estimate is mitigated by the fact that relative to gold, silver adds little value to any potential mining operation.

RESPEC believes that any factors that would likely influence the prospect of economic extraction have either been addressed or could be resolved by further drilling.

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12 MINERAL RESERVE ESTIMATES

12.1 Introduction

Mineral Reserves were estimated by Qualified Persons of RESPEC and classified in order of increasing confidence into Probable and Proven categories to be in accordance with definitions in Subpart 229.1300 – Disclosure by Registrants Engaged in Mining Operations in Regulation S-K 1300. RESPEC is independent of Paramount and has no affiliations with Paramount except that of an independent consultant/client relationship.

12.1.1 Estimation Procedure

The Mineral Reserve is composed of material which was classified as an open pit mineral resource. There was a negligible quantity of underground resources reported outside of resource open pit shell, but these are not part of mineral reserve.

An underground mining scenario is assumed using mechanized cut-and-fill methods, which, following ramp-up, will produce 1,200–1,400 ton/d, four days a week. This mining rate will provide sufficient material for the 750 ton/day mill and processing plant to operate at full capacity for seven days a week. The underground cut-and-fill mining method was selected based on minimizing the environmental impacts. The underground cut-and-fill mining method has a significant smaller footprint compared to open pit mining methods. Underground stoping and other larger underground mining methods were not selected because the size and geometry of the ore body do not support a higher production rate.

The Proven and Probable reserves for Grassy Mountain have been estimated by first calculating an economic net smelter return (NSR) cut-off for mining underground stopes, then using the NSR cut-off to design stope shapes centered on Measured and Indicated Mineral Resource blocks with the mining revenue greater than or equal to the NSR cut-off. The QP used the resource block model described in Section 11, in GEOVIA Surpac and Deswik formats. All Inferred material was considered to be waste with no value or metal content. Internal and external dilution and mining recoveries (ore loss) were estimated and applied as modifying factors based on the total tonnage of material inside of the final designs. The following sections provide details on the assumptions and design criteria used for estimating the reported Proven and Probable Mineral Reserves.

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12.2 Mineral Reserve Statement

The reference point for the estimated Mineral Reserves is the crusher. Section 11.8 describes the conversion of Mineral Resources to Mineral Reserves.

The Mineral Reserves estimated for the Grassy Mountain Project are provided in Table 12-1 and have an effective date of May 15, 2026. An underground mining scenario is assumed in this study using mechanized cut-and-fill methods. The Qualified Person responsible firm for the mineral reserves estimate is RESPEC. The reference point at which the Mineral Reserves are defined is the point where the ore is delivered to the FS mill crusher.

Table 12-1: Mineral Reserves Statement

		ktons		Grade (oz/ton Au)		Grade (oz/ton Ag)		Gold (k oz)		Silver (k oz)
Proven mineral reserves		299		0.167		0.256		50		76
Probable mineral reserves		1,908		0.186		0.287		355		548
Proven + Probable reserves		2,207		0.184		0.283		405		624

Notes:

• Mineral reserves have an effective date of May 15, 2026.

• Mineral Reserves are reported inside stope designs assuming drift-and-fill mining methods, and an economic net smelter return cutoff of $201 per ore ton processed. The economic cut-off grade estimate uses a gold price of $2,750/oz, mining costs of $141/ton processed, surface re-handle costs of $0.22/ton processed, process costs of $39/ton processed, general and administrative costs of $20/ton processed, and refining costs of $6/oz Au recovered. Cost inputs mentioned here are rounded except the surface re-handle costs.

• Metallurgical recovery utilizes the recovery schedule discussed in Section 10.5.

• Mineralization that was either not classified or was assigned to Inferred Mineral Resources was set to waste.

• A 1.5% NSR royalty is payable.

• Rounding may result in apparent discrepancies between tons, grade, and contained metal content.

12.3 Economic Cut-off Grade Calculation

12.3.1 Gold Price

The gold price used for the cut-off grade estimation is $2,750/oz Au. The gold daily closing monthly averages in $/oz Au from the World Gold Council is shown in Figure 12-1 for the three-year period leading up to February 2026. The 24-month average for the period ending in February 2026 is $3,139/oz Au, the 36-month average is $2,752/oz Au, and the 18-month average is $3,677/oz Au.

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Figure 12-1: Monthly Average Gold Price, $/oz

Source: World Gold Council, 2026

The economic cut-off grade used for stope design is based on initial economic parameters shown in Table 12-2.

Table 12-2: Cut-off Grade Input Parameters for Gold Metal

Name		Quantity		Unit
UG Mining costs		141.18		$/ton processed
Surface Rehandle		0.22		$/ton processed
Process Costs		39.09		$/ton processed
G&A Costs		20.15		$/ton processed
Total Operating Costs		200.64		$/ton processed
Refining Cost		6.00		$/oz processed
NSR Royalty		1.5%		percent
Gold Metal Recovery		92.8%		percent
Gold Selling Price		2,750		$/oz Au
Calculated Cutoff Grade		0.080		oz Au/ton
Mineral Reserve Cutoff Grade Used		0.080		oz Au/ton
NSR Economic Cutoff		201.00		$/ton processed

Note: G&A = general and administrative.

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The calculated gold cut-off grade is 0.08 oz/ton Au. Variable leach recovery depending on the feed grade was used to assign NSR value in the block model. The NSR economic stope cutoff was used in the stope optimization to identify the Measured and Indicated blocks available for consideration to be converted to Mineral Reserves. Deswik SO 5.13878 version was used for stope optimization. Measured and Indicated resource blocks with NSR value less than the economic stope NSR cut-off, as well as all Inferred resource blocks irrespective of grade, were considered as waste and applied to internal dilution.

12.3.2 Silver Price

The silver price used for the economic NSR cut-off evaluation is $31.00/oz Ag. The 24-month average for the period ending in February 2026 is $39.49/oz Ag, the 36-month average is $34.19/oz Ag, and the 18-month average is $43.18/oz Ag.

The silver metal at Grassy Mountain has a minimal impact on the economics of the project. Table 12-3 shows the Total Mineral Reserves multiplied by the respective metal prices for gold and silver. The silver metal contributes to less than 2% of the total revenue.

Table 12-3: Total Mineral Reserves Multiplied by the Metal Price

Metal		Total Mineral Reserves (‘000 oz)		Metal Price ($/oz)		% Contribution to Revenue
Gold		405		2,750		98%
Silver		624		31		2%

A calculated silver cut-off grade was not used in the mine design due to its relatively small (<2%) contribution to total economic value as shown in Table 12-3. The economic NSR cut-off grade of $201/ore ton processed was used for determining the stope designs in mineral reserve designs inclusions. Revenue for silver is included in the financial model, and therefore silver grade and silver contained metal are reported in the estimated Mineral Reserves.

12.4 Stope Design

The Mineral Reserves were constrained by the design of mineable stope shapes centered on Measured and Indicated blocks with grades greater than the economic stope cut-off. For stope optimization, the Stope Optimizer SO 5.1 3878 module from Deswik™ software was used. The stope optimization parameters are stated in Table 12-4.

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Table 12-4: Stope Optimization Parameters

Attribute		Quantity		Unit
Height		15		ft
Width		15		ft
Round length		10		ft
Minimum optimization length		20		ft
Maximum optimization length		50,000		ft
Minimum stope pillar		5		ft
Slice interval		2		ft
Evaluation method		Exact Geometric		-

Each stope block was queried against the resource block model to determine the tonnages and grades within the stope shapes. Stopes with an average measured or indicated gold grade equal to and above the economic NSR cut-off were selected to be included in the mine plan and Mineral Reserves estimate. Some isolated stopes above the cut-off grade threshold were eliminated from consideration because the development to extract them would cost more than the economic return. Dilution and recovery were not considered during the stope optimization. The dilution and recovery were applied as modifying factors later in the process.

Development designs were generated concurrently for each stope shape with the purpose of minimizing development in waste. Figure 12-3 shows a typical mine production-level design. These designs were done every 15 vertical feet.

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Figure 12-2: Mine Production Design of Level 3210, Plan View

Source: MDA, 2020 (for representation purposes only, MDA is now part of RESPEC).

12.5 Dilution and Recovery

12.5.1 External Dilution

A modifying factor of 8% was used for calculating external dilution tons. Grade was assigned to the external dilution by expanding the stope limits by one foot on all sides that are not adjacent to other stopes. The resource block model was queried against the expanded volume and 80% of the queried grade was used to determine the appropriate external dilution grades for silver and gold.

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12.5.2 Internal Dilution

All Inferred resource blocks or partial blocks within the stopes and all unclassified material within the stopes is considered internal dilution. The tons were accounted for with zero grade.

12.5.3 Mining Recovery

Mining recovery is estimated to be 97% based on an assumed ore loss of 3%. This is considered appropriate for the highly selective mechanized cut-and-fill mining method selected for the Grassy Mountain deposit and it is based on similar operations in disseminated ore bodies.

12.6 Discussion of Mineral Reserves

The QP is not aware of any mining, metallurgical, infrastructure, permitting or other relevant factors not discussed in this Report that could materially affect the mineral reserve estimate. The economic viability of Grassy Mountain is disclosed in Section 19. Further conclusions are disclosed in Section 22.

12.7 Classification

All design solids were determined to be either ore or waste as shown in Figure 12-4. All mine design solids above the cut-off-grade were designated as ore. All mine design solids below the cut-off-grade were designated as waste. The block model classified each block as either measured, indicated, or inferred as follows:

• All tons within the ore mine design solids and classified as measured in the block model were classified as Proven.

• All tons within the ore mine design solids and classified as indicated in the block model were classified as Probable.

• All tons within the ore mine design solids and classified as inferred in the block model were classified as Ore Loss.

These parameters are listed in Table 12-5. Please note that a single mine design solid could contain multiple blocks with different block model classifications. These were segregated according to Table 12-5. Therefore, the classification was done at the block model resolution and not at the mine design resolution.

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Figure 12-3: Ore and Waste Designation

Source: RESPEC, 2026

Table 12-5: Reserve Classification Parameters

Class		Mine Design Criteria		Classification from the Block Model
Proven		Ore material above the Cut-Off-Grade		Measured
Probable		Ore material above the Cut-Off-Grade		Indicated
Ore Loss		Ore material above the Cut-Off-Grade		Inferred

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13 MINING METHODS

13.1 Mining Method Selection

The mechanized underhand cut-and-fill mining method was selected using the methodology proposed by Nicholas (1981). Cemented rock fill (CRF) will be used for backfill. The mechanized cut-and-fill method is highly flexible and can achieve high recovery rates in deposits with complex geometries, as is the case at the Grassy Mountain deposit. The estimated mine life is nine years.

13.1.1 Underhand Mechanized Cut-and-Fill Mining

The Grassy Mountain mine will be an underground operation accessed via one decline and a system of internal ramps. Stacked set of raise is included in the design to be used for ventilation and secondary egress as shown in Figure 13-1. A plan view of the proposed mine design is shown in Figure 13-2.

Figure 13-1: Grassy Mountain Mine Cross-section Looking North

Source: RESPEC, 2026

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Figure 13-2: Proposed Grassy Mountain Mine Plan (plan view)

Note: The mine design was based on an average production rate of 1,200 -1,400 tons per day using a four-day-on and three-day-off schedule, with two 12-hour shifts per day, to provide 24-hour coverage during the four operating days at full operation. This will provide sufficient material to feed 750 tons/d to the mill on a seven day per week basis. Source: RESPEC, 2026

The nominal development size will be 15 ft wide by 15 ft high as shown in Figure 13-3. The nominal Topcut-A production size is to be 15 ft wide by 15 ft high as shown in Figure 13-3. The Topcut-A will be used when the material above is native rock. The nominal Undercut-B production size is to be 20 ft wide by 15 ft high as shown in Figure 13-3. The Undercut-B will be used when the material above is cemented backfill from a Topcut-A production drift as shown in Figure 13-4. The nominal Undercut-C production size is to be 30 ft wide by 15 ft high as shown in Figure 13-3. The Undercut-C will be used when the material above is cemented backfill from an Undercut-B as shown in Figure 13-4. This heading layout will tolerate weak ground conditions while still maximizing production in a cut-and-fill mine.

The sizes will allow the miners and associated diesel mining equipment access and flexibility to maximize production from the mine as well as minimize waste haulage from the development headings.

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Figure 13-3: Drift Profiles

Source: MDA, 2020 and used unmodified by RESPEC in 2026

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Figure 13-4: Production Drift Layout (Section Looking East)

Note: The mining cycle involves drilling, blasting, and mucking for the development and production access. The final part of the mining cycle is to backfill the stopes. Source: MDA, 2020 and used unmodified by RESPEC, 2026

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13.1.2 Mining Method Sequence

The mining sequence contains a mining level sequence and an underhand production stope sequence. The level sequence for a typical level can be seen in Figure 13-5. The level access is mined first. The mains are mined second. Typically, two mains are mined at the same time providing multiple mining locations on a level. After the mains are mined, then the production drifts can begin mining. The production drifts are sequenced with primaries and secondaries. The primaries are mined and backfilled first allowing for a backfill minimum cure time of 14-days between the primaries and secondaries. This continues as shown in Figure 13-5 until the entire level is complete. After the entire level is complete the level access is backfilled and a 28-day delay for the cure time is applied. After the cure time is complete the level below can start.

Figure 13-5: Detailed level Sequence for a Typical Level

Note: The underhand mining sequence is grouped into lifts as shown in Figure 13-6. Source: MDA, 2020 and used unmodified by RESPEC, 2026

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Figure 13-6: Mining Lifts

Source: MDA, 2020 and used unmodified by RESPEC, 2026.

One level in each lift can be mining at any given time during the life of mine. The underhand sequence starts at the top and works down in elevation. Constraints are applied to ensure that the bottom level of a lift does not conflict the top level of the lift below.

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13.2 Geotechnical Analysis

13.2.1  Overview

The Grassy Mountain deposit is situated is a horst block which has been raised 50–200 ft in a region of complex block faulting and rotation. Faulting is dominated by post-mineral N30ºW to N10ºE striking normal faults developed during Basin and Range extension. On the northeast side of the deposit, these faults progressively down-drop mineralization beneath post-mineral cover. These offsets are suggested by interpreted offsets in drill holes of a prominent white sinter bed, as well as intersections with a fault gouge. The N70ºE striking the Grassy Mountain fault shows a minor vertical offset of 10–40 ft.

The North and Grassy faults are significant fault structures that pose a risk to the stability of an open stoping method; hence, these areas are considered suitable only for a limited man-entry mining method such as mechanized cut-and-fill, where conditions can be well controlled.

Degradation of the Grassy Mountain Formation results in difficult mining conditions that can be mitigated through additional ground support, which would involve a higher mining cost with slower advance rates in those areas.

Stress measurements are not currently available. In the absence of this information, a stress regime based on the World Stress Map was used to obtain a range of estimates. Based on the shallow depth, ground stress is relatively low, and rock damage due to higher mining-induced stress concentrations is only anticipated in high-extraction or sequence closure areas and weaker rock mass areas. However, a reduction in the mining stresses around excavations is likely to adversely affect the stability of large open-span areas. Tensile failure and gravity-induced unraveling are foreseen as the main failure mechanisms.

The Grassy Mountain deposit is in a structurally complex, clay-altered, epithermal environment. Rock mass conditions in the infrastructure and production areas vary from Poor to Fair quality (RMR 20–45; RMR mean 40–45) with the poorest conditions within major structures that run longitudinally through and bound the deposit. Outside of these fault areas, rock mass conditions are generally Fair. However, localized zones of Poor ground potentially associated with secondary structures or locally elevated alteration intensity are present throughout the planned mining area.

Excavation stability assessments were completed using industry-accepted empirical relationships, with reference to analogue mines where possible. The rock mass conditions (Poor to Fair) are considered suitable only for a selective underground mining methods and limited sizes.

Ground support design considers industry-standard empirical guidelines and GMS’s experience in variable ground conditions. Compromises have been made in the extraction sequence due to the need to balance grade and production profiles, extraction of wide orebody areas, and other geotechnical constraints. Ultimately, some aspects of the sequence may not be geotechnically optimal, and additional analysis or design may be required.

The North and Grassy faults are significant fault structures that pose a risk to the stability of an open stoping method; these areas are therefore considered suitable only for a limited man-entry mining method such mechanized cut and fill, where conditions can be well controlled. Two secondary structural systems have been identified, which cut and cause slight dislocations in the veins and mineralized bodies: one corresponding to normal-displacement structures with a north–northeast–south–southwest strike and the other with a northwest–southeast strike. Not all fault structures could be modelled, and the influence of several secondary- and tertiary-level structures in the deposit are not well understood. Several fault structures will need to be further defined and interpreted during the decline ramp excavation program.

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13.2.1.1  Degradation Zones

Time-dependent drill core degradation has previously been identified at Grassy Mountain. In general, degraded zones are contained within siliceous sinter bodies, conglomerates, and interbedded tuff beds within the Grassy Mountain Formation. Degradation is strongest in intervals that are observed or interpreted as having contained silicic and potassic alteration. Contacts of the Grassy Mountain Formation were used to extrapolate degradation zones beyond areas of graphically-logged intervals in order to construct moderate- and high-confidence degradation shells. Across the deposit, the North and Grassy faults produce significant degradation above and below the conglomerates and tuff strata, and the faults to the west appear to displace or bound the degradation zone.

Degradation of Grassy Mountain Formation lithologic units results in difficult mining conditions that can be mitigated through additional ground support. This would result in a higher mining cost with slower advance rates in those areas.

13.2.1.2  Structural Fabric

The geotechnical holes drilled in the 2016–2017 campaign were drilled with “triple tube” techniques to increase core integrity and preservation for best geotechnical logging and measurements. Observations of the core suggest that there is little systematic structure, except for the very steep features often sub-parallel to the core axis that are likely oriented similarly to the interpreted northwest–southeast-striking faults associated with mineralization. The remaining structure is typically very small-scale, irregular, and generally related to micro-defects within the rock mass.

13.2.1.3  In-situ Stress

Stress measurements are not currently available. In the absence of this information, a stress regime based on the World Stress Map was used to obtain a range of estimates. Uncertainty in the stress magnitude will need to be further assessed and interpreted during the decline ramp excavation program.

Based on the shallow depth, ground stress is relatively low, and rock damage due to higher mining-induced stress concentrations is only anticipated in high-extraction or sequence closure areas and weaker rock mass areas. However, a reduction in the mining stresses around excavations is likely to adversely affect the stability of large, open-span areas. Tensile failure and gravity-induced unraveling are foreseen as the main failure mechanisms. The pre-mining stress field should be further evaluated.

13.2.2  Geotechnical Characterization

A geotechnical investigation was carried out by Golder in 2017 and Ausenco in 2018 to characterize rock mass conditions in support of an underground design for the 2018 PFS. A combined total of 27 core holes were drilled through the deposit and geotechnically logged and sampled for laboratory strength testing as part of the 2016–2017 program. Point load testing was also conducted on cores retrieved from the geotechnical drill holes. After the 2016–2017 core holes program, GMS geotechnically logged two core holes from the 2019 program.

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The geotechnical database from the 2016–2017 program was checked against the respective core photographs for internal data consistency and the data are considered to be suitable for a feasibility-level study.

Overall, the following information was used to base geotechnical assessments:

• 2016–2017 core holes database with RQD and core recovery data

• Core photographs for 2016–2017 core holes

• Detailed geotechnical logging for 25 holes by Paramount under Golder training and review (2016–2017)

• Detailed geotechnical logging for two holes by Golder (2016–2017)

• Detailed geotechnical logging for two holes by Paramount (2019)

• Field point load testing of cores from six holes (total of 300 tests) during the 2016–2017 program and from two holes (total of 166 tests) during the 2019 program

• Laboratory strength testing for two programs (2016–2017 and 2019) including uniaxial compressive strength (UCS), Brazilian tensile strength, and elastic properties.

13.2.3 Golder Geotechnical Appraisal

A geotechnical appraisal of the proposed underground mine area was carried out by Golder during 2016–2017 (Golder Associates Inc, 2018). Geotechnical data were available from three different drilling programs that were completed prior to the 2016–2017 drill program. Calico, Newmont, and Atlas carried out RQD measurements. Additional geotechnical data from Newmont and Calico drilling were reviewed but not used directly in Golder’s 2016–2017 evaluation, due to uncertain reliability and consistency in the data.

Two holes were logged in detail for geotechnical characterization by Golder personnel at the drill rig. The other 2016–2017 holes were logged by Paramount personnel according to Golder’s instructions and procedures (25 core holes).

Golder used the geotechnical log data to characterize the orebody and surrounding rock mass, based on an RMR calculation from the logged data. Figure 13-7 presents the RMR76 histogram for all core that was geotechnically logged from the 2016–2017 drill program. The pre-2016–2017 Calico, Newmont, and Atlas historical data were not evaluated with the 2016–2017 program. Golder did not consider the pre- 2016–2017 data usable with the 2016–2017 RMR log data.

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Figure 13-7: Golder Rock Mass Rating (all 2016–2017 core)

Source: Golder, 2018

Golder’s drill core review in 2016–2017 indicated the presence of a significant number of zones of broken rock fragments within what Golder termed “a matrix of soil” and referred to as “Soil Matrix Breccia”. These zones are more correctly referred to as “Clay Matrix Breccia”. The Clay Matrix Breccia, an important contributor to Type III rock quality (Table 13-1) is readily observed in cores in split tubes immediately after drilling, but it is also clearly identifiable after the core has been boxed and somewhat disturbed.

Table  13-1: Rock Quality Categories

Rock Quality Category		Description		Approximate Expected Percent of Excavations (a) (%)
Type I		Moderately fractured rock		20
Type II		Poor quality, highly fractured rock		40
Type III		Clay matrix breccia and other very poor-quality rock (clay, broken rock and rubble in core boxes)		40 (15% clay matrix breccia, 25% other poor-quality rock)

Note: Based on percent encountered within 2016–2017 drill holes.

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The geological and geotechnical data did not identify any trends or patterns that would allow the delineation of rock quality domains for mine design, with the exception of Very Poor-quality rock encountered in and around the interpreted sub-vertical structures. However, Very Poor-quality rock was not limited to the vicinity of the structures; it was also frequently observed between structures. This degree of variability required a selective mining method that can quickly respond to changing ground conditions.

Golder (2018) concluded that, in the absence of spatial patterns in rock quality, three categories of rock quality should be applied for PFS-level design and cost estimating purposes (refer to Table 13-1).

13.2.4 Ausenco Geotechnical Work

In 2017, Ausenco’s geotechnical group conducted a review of all the available geotechnical information provided by Paramount, including core logs and core photographs. The main objectives were to select a mining method and develop recommendations for support in underground openings.

Ausenco’s geotechnical group reviewed all core photographs from the 2016–2017 core drilling program and estimated additional geotechnical parameters that were incorporated into the geotechnical review.

In order to characterize the rock mass of the deposit, a statistical analysis was performed on the geotechnical data derived from the core logging by Paramount and Golder. The RMR76 results analyses are shown in Figure 13-8.

Figure 13-8: RMR 76 Histogram from 27 Drill Holes

Source: MDA, 2017

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Per the analysis conducted by Ausenco, the majority of the ground conditions of the Grassy Mountain deposit are classified as being of Fair to Poor rock quality, and the RMR is typically less than 49.

Based on RMR76 statistics and Ausenco’s interpretation and correlation with the geological database, it can be concluded that Golder’s previous analysis (unknown at that time), with the same data, had very similar results.

The Grassy Mountain deposit was assigned by Ausenco to three rock classes by geotechnical quality:

• Class 1: Rocks of Poor geotechnical quality according to RMR76; approximately 40% of the deposit.

• Class 2: Rocks of Fair geotechnical quality according to RMR76; approximately 50% of the deposit.

• Class 3: Rocks of Good geotechnical quality according to RMR76; approximately 10% of the deposit.

Table 13-2 shows the cumulative frequency values based on the RMR76 histogram from 27 drill holes (Figure 13-9) with the rock classes assigned by Ausenco.

Table  13-2: Rock Quality Categories

Rock Quality (RMR)				Frequency (%)		Rock Class		Deposit (%)
0–20		Very Poor		1.8		—		—
20–40		Poor		38.3		Class 1		40
40–60		Fair		49.4		Class 2		50
60–80		Good		9.3		Class 3		10
80–100		Very Good		1.2		—		—

The Very Poor and Very Good rock qualities, according to the RMR classification, are not representative of the deposit due to the low frequencies measured, so they were omitted from the three rock classes assigned. However, they do exist and should be considered when mining, in particular the Very Poor quality, which may require additional support.

Examples of the three 2017 RMR classes are shown in Figure 13-9.

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Figure 13-9: Examples of Three Geotechnical Rock Classes

Source: MDA, 2017

13.2.5 Feasibility Study Geotechnical Analysis

The basic geotechnical parameters recorded in the field during the 2016–2017 and 2019 drill holes program were combined to form an RMR system (Bieniawski, 1976). These data were used to create an RMR profile with depth for each of the geotechnical holes drilled. The RMR76 system consists of a rating scale accounting for intact rock strength (IRS), fracture frequency per meter (ff/m), joint conditions, and groundwater. RMR values consider a maximum possible value of 100 for each run. Dry conditions were assumed for RMR calculations, as groundwater pressures are accounted for during the stability analysis using effective stress type analyses. A summary of RMR values per area of the deposit is presented in Table 13-3.

Table  13-3: Summary of RMR (Bieniawski, 1976) Values by Area

Area Data		RMR (B76)								Data (no)
		Mean				Standard Deviation
Decline ramp/mine infrastructure			38				18				226
Stopes (drifts)			40				18				1,123
Crown pillar			41				19				242
Centre of deposit (Section)			38				20				149

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Data from the geotechnical core logging and the statistical analysis indicate that the geotechnical units have similar geotechnical conditions. The data indicate that the deposit presents no substantial differences in geotechnical qualities among the stope areas and mine infrastructure location, including the intersections with faults or veins, which present Poor to Very Poor qualities. In general, the deposit presents a high variability in geotechnical qualities over short distances, but with a similar behavior for the whole area of the proposed mine. This assumption can be refuted or confirmed by the rock quality observed in the core trays shown in Figure 13-10.

Figure 13-10: GM19-37 Core Trays (89.5 to 105.5 ft.) – High Variability in Geotechnical Conditions

Source: GMS, 2020

13.2.5.1  Intact Rock Strength

Physical testing of suitable rock core specimens allows determining the mechanical properties of intact rock required for mine design using rock mass classification or numerical analysis methods. The IRS is commonly measured in uniaxial compression, point load, indirect tensile, and triaxial compression tests (Brady and Brown, 2004). Usually, a limited (but representative) number of cylindrical specimens of each rock type should be tested for UCS in a suitable laboratory equipped with a stiff testing machine. A larger number of point load tests can be carried out during the core logging process for orebody delineation. A comprehensive set of suggested testing methods has been published by the International Society for Rock Mechanics (ISRM) (Brown, 1981; Ulusay and Hudson, 2007).

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Golder selected core samples for laboratory testing from six of the 2016–2017 geotechnical core holes. Samples from one of the 2019 geotechnical core holes were also selected by GMS for laboratory testing. The samples were submitted to Golder’s laboratory in Burnaby, British Columbia.

Point load tests (PLTs) were conducted by Paramount geologists in the core shed after geotechnical logging, in keeping with the ASTM Standard D 5731-07: Determination of the Point Load Strength Index of Rocks, and Application to Rock Strength Classifications. PLTs were performed at approximately 10-ft intervals down hole.

Table 13-4 provides a summary of the IRS parameters by geotechnical units considering the median depths where the deposit is located.

Table 13-4: Intact Rock Strength for Geotechnical Units Calculated from PLTs

Geotechnical Unit		H (ft)				Intact Rock
						mi*				CS (Mpa)				Ei** (Gpa)				γ(T/m3)
GTU-2 (sandstone/arkose (D=0.5))			492				12.7				116.70				60.2				2.47
				984
GTU-2 (sandstone/arkose (D=0))			492				12.7				116.70				60.2				2.47
				984
GTU-3 (siltstone (D=0.5))			492				7.0				101.92				46.9				2.49
				984
GTU-3 (siltstone (D=0))			492				7.0				101.92				46.9				2.49
				984
GTU-4 (tuff (D=0.5))			492				13.0				158.08				57.1				2.44
				984
GTU-4 (tuff (D=0))			492				13.0				158.08				57.1				2.44
				984
GTU-5 (sinter (D=0.5))			492				13.1				120.92				69.7				2.45
				984
GTU-5 (sinter (D=0))			492				13.1				120.92				69.7				2.45
				984
GTU- 6 (conglomerate (D=0.5))			492				21.0				90.41				69.45				2.47
				984
GTU-6 (Conglomerate (D=0))			492				21.0				90.41				69.45				2.47
				984

* mi: material constant for the intact rock

** Ei (Gpa): intact rock modulus

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13.2.6 Geotechnical Model

The geotechnical model for this Report is the final result of the combination of the geological model, the rock mass fabric descriptions, the rock mass strengths, and the hydrogeological model. This geotechnical model describes the rock mass units from an engineering perspective through geotechnical domains. Geotechnical domains are zones showing similar geotechnical properties, based on rock type, rock mass strength, and geological characteristics. In particular, in the Grassy Mountain deposit the geotechnical domains are controlled by the lithology present and its alteration grade as geotechnical units. Seven geotechnical units were identified:

• Cover soil

• Sandstone/arkose

• Siltstone-mudstone

• Tuff

• Sinter

• Conglomerate

• Clay matrix breccia.

Overall, the first layer corresponds to cover soil with a thickness of less than 9.8 ft. Below that is a jointed rock mass mainly composed of a series of layers of sandstone/arkose, siltstone, tuff, sinter, and conglomerate. The layers do not follow any sequence between geotechnical units, and clay matrix breccia can be located between every geotechnical unit combination around the deposit and, especially, close to drifts. In general, all the geotechnical units are highly jointed and have strengths between 95–135 Mt/a.

A statistical analysis was performed to provide the frequency of geotechnical qualities per each geotechnical unit. The RQD, RMR76, and GSI 2013 values are summarized in Table 13-5.

The rock mass quality of the deposit’s geotechnical units does not improve with depth. Around faults/veins, the geotechnical units are in Very Poor-quality rock with an RMR of less than 30. However, Very Poor-quality rock is not limited to the vicinity of the faults/veins; it is also frequently observed between faults/veins. There is no clear evidence that these zones correspond to the veins, but the statistical analysis of RMR76 and PLT values indicates that the geotechnical units have a separate population with low values in the approximate location of the faults/veins.

Based on the RMR76 statistics and the current interpretation and correlation with the previous geotechnical analysis conducted, it can be concluded that the defined geotechnical units are classified as being of Fair to Poor rock quality, represented by an RMR76 of typically less than 48 and a GSI2013 of less than 45.

Core logging data suggest that the generalized Hoek-Brown failure criteria is a suitable method for calculating the rock mass strength parameters for all of the units, because the majority of the rock mass is considered jointed hard rock material. When RMR values are less than 23, the Hoek-Brown failure criteria are no longer applicable because strength parameters are not strongly dependent on confinement.

Table 13-5 provides a summary of rock mass strength parameters by geotechnical units considering the median depths where the deposit is located.

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Table 13-5: Summary of RQD, RMR76, and GSI 2013 Values by Geotechnical Unit

Geotechnical Unit (GTU)		Description		RQD								RMR76								GSI2013
				Weighted Mean				Weighted Standard Deviation				Weighted Mean				Weighted Standard Deviation				Weighted Mean				Weighted Standard Deviation
1		Cover soil			NA				NA				NA				NA				NA				NA
2		Sandstone, arkose			50.3				26.8				48.0				12.7				45.1				21.0
3		Siltstone, mudstone, breccia			41.2				26.8				42.6				12.4				37.4				20.4
4		Tuff			41.7				27.6				41.7				10.2				38.8				22.3
5		Sinter			35.0				30.4				44.7				11.1				37.1				22.0
6		Conglomerate			NA				NA				NA				NA				NA				NA
7		Clay matrix breccia			23.4				28.1				30.1				13.6				18.9				19.3

Note: NA = not applicable.

Table 13-6: Strength Parameters for Geotechnical Units

Geotechnical Unit		H (ft)				Rock Mass
						GSI				mb				s				a				s TM (Mpa)				E H-D2005 (Gpa)				v				C (kPa)				∅ (°)
GTU-2 (sandstone/arkose (D=0.5))			492				45				0.929				0.0007				0.508				-0.082				6.37				0.26				798				48.0
				984																																																												1184				42.8
GTU-2 (sandstone/arkose (D=0))			492				45				1.788				0.0022				0.508				-0.145				13.46				0.26				1075				52.9
				984																																																												1542				48.0
GTU-3 (siltstone (D=0.5))			492				37				0.349				0.0002				0.514				-0.066				3.01				0.27				525				38.3
				984																																																												777				33.1
GTU-3 (siltstone (D=0))			492				37				0.738				0.0009				0.514				-0.126				6.10				0.27				743				44.5
				984																																																												1065				39.3
GTU-4 (tuff (D=0.5))			492				37				0.647				0.0002				0.514				-0.055				3.66				0.27				717				47.2
				984																																																												1088				42.0
GTU-4 (tuff (D=0))			492				37				1.370				0.0009				0.514				-0.105				7.42				0.27				987				53.0
				984																																																												1453				48.1
GTU-5 (sinter (D=0.5))			492				37				0.652				0.0002				0.514				-0.042				4.47				0.27				646				45.2
				984																																																												986				39.9
GTU-5 (sinter (D=0))			492				37				1.381				0.0009				0.514				-0.080				9.06				0.27				875				51.2
				984																																																												1308				46.2
GTU- 6 (conglomerate (D=0.5))			492				40				1.206				0.0003				0.511				-0.025				5.34				0.27				706				48.2
				984																																																												1099				43.0
GTU-6 (conglomerate (D=0))			492				40				2.464				0.0013				0.511				-0.047				11.09				0.27				916				53.7
				984																																																												1410				48.8

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13.2.7 Summary of Geotechnical Analysis and Evaluation for Underground Mining

The QP believes the available geotechnical data are adequate for designing the mine openings associated with the estimation of the Grassy Mountain Mineral Reserves at the current stage. Risks associated with the current level of geotechnical analysis are discussed in Section 22.18, and recommendations for additional work are presented in Section 23.4.

While the rock quality is variable and the deposit is mineable based on the chosen mining method, care must be taken during the execution of the mine plan. The selected mining method and underground support recommendations are specified in Sections 13.4 and 13.5 of this Report.

As part of the 2026 Feasibility Study Update, GMS reviewed the updated mine planning information, underground mine layouts, mine sequencing information and production schedule provided by RESPEC. Based on the review completed, no material changes were identified that would require modification of the geotechnical characterization, geotechnical domains, rock mass classifications or geotechnical design assumptions presented in this chapter.

13.3 Hydrogeological modelling

A hydrogeological assessment of the mine site was completed by Lorax Environmental Services (March 2020) in a report titled “Grassy Mountain Gold and Silver Project Mine Dewatering Hydrogeologic Assessment”, which included baseline reports for groundwater and dewatering analysis. This report is used as the basis for underground dewatering requirements in Section 15.7.3.

13.4 Excavation Design

13.4.1 Mining Method Selection

The selection method assessment was carried out during the 2018 PFS according to the methodology proposed by Nicholas (1981), where the deposit geometry and the geotechnical parameters are assessed as main parameters. In particular, the methodology provides a ranking of mining methods in order to incorporate economic parameters for the final selection.

The design factors that influence the choice of mining method include:

• Orebody geometry (e.g. vein shape, thickness, dip, etc.) and grade distribution within the deposit

• Rock mechanics characteristic of the veins, hanging wall, and footwall rock mass

• Mining costs and capitalization requirements

• Mining rate

• Type and availability of mining labor

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• Environmental concerns

• Other site-specific considerations.

The assessment suggested the mechanized cut-and-fill mining method would be most appropriate for the Grassy Mountain Project.

The mechanized cut-and-fill method is highly flexible and can achieve high recovery rates in deposits with complex and flat-dipping geometries, as is the case at the Grassy Mountain deposit.

As part of the 2026 Feasibility Study Update, the revised underground mine plan, mine layouts, mine sequencing information and production schedule prepared by RESPEC were reviewed by GMS from a geotechnical perspective. Based on the information provided, no material changes were identified that would affect the suitability of the selected mining method or require revision of the geotechnical basis of design supporting the mining method selection.

13.4.2 Drift Sizes and Stability Assessments

Preliminary dimensioning was carried out during the 2018 PFS using the empirical design proposed by Mathews (1980). The analysis provided the hydraulic radius for the maximum drift dimension under 60% stability conditions.

The stability graph is a function of the stability number, which represents the ability of the rock mass to remain stable under certain operating stress conditions as a function of the hydraulic radius, which represents the geometry of the stope surface. The main concept associated with the stability graph is that the surface size of an excavation can be related to the strength properties of the rock mass, so as to have an idea of the associated stability or instability.

The rock mass conditions in the Poor to Fair rock mass range are considered suitable only for a man-entry method where conditions can be well controlled, such as mechanized cut-and-fill.

The current analysis aims to validate the drifts dimensioning defined for the 2020 FS. For that, the Q’ value was obtained from the geotechnical characterization using RMR76, particularly considering GTU-2 as the most frequent geotechnical unit in the deposit.

Iso-probability contours, which relate the stability number and the hydraulic radius, were used to calculate drift dimensions stability for stable cases (Figure 13-11; Table 13-7).

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Figure 13-11: Iso-Probability Contours for Stable Cases

Source: GMS, 2020; after Mawdesley, 2001

Table 13-7: Iso-Probability Contours for Stable Cases Results

Drift		B–E Walls (Roof) Stable (%)		H–F Walls (Wall) Stable (%)
Topcut A		>95		>95
Undercut B		≈90		>95
Undercut C		≈80		>95

The results show that, for the current dimensions, the hanging wall and foot wall would present a probability of stability of more than 95%, and the back and end walls would present a probability of stability of more than 95% for Topcut A, of around 90% for Undercut B, and of around 80% for Undercut C.

The iso-probability contours for failure cases are shown in Figure 13-12 and Table 13-8.

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Figure 13-12: Iso-probability contours for failure cases (Mawdesley, 2001)

Source: GMS, 2020

Table 13-8: Iso-Probability Contours for Failure Cases Results

Drift		B–E Walls (Roof) Failure (%)		H–F Walls (Wall) Failure (%)
Topcut A		<10		<10
Undercut B		<10		<10
Undercut C		~20		<10

The results show that, for the current dimensions, the Hanging and Foot Walls would present a probability of failure of less than 10%, and the Back and End Walls would present a probability of failure of less than 10% for Topcut A and Undercut B, and of around 20% for Undercut C.

As part of the 2026 Feasibility Study Update, GMS reviewed the updated underground mine plan, mine layouts, mine sequencing information and production schedule. Based on the review completed, no material changes were identified that would require revision of the excavation design criteria, excavation geometries or geotechnical design assumptions supporting the excavation designs presented herein.

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13.5 Numerical Modelling

Numerical assessments using RS2 and FLAC3D have been completed to evaluate the extraction sequence, decline ramp and drift stability, stress migration, potential damage to infrastructure, and subsidence, even though the mine will be at relatively shallow depths (500–900 ft below ground surface).

To complement empirical methods and validate the support design, a detailed two-dimensional numerical analysis was carried out using the RS2 program (Rocscience, 2020). The purpose of these numerical models is to assess the effect of the in-situ stress on the excavation and the response of the reinforcement and support elements.

The results for the decline ramp (Figure 13-13) indicate the following:

• In general, the maximum principal stress (S1) contours show high compressive stresses at the toe of the walls and above the roof at 1.6 ft, and a relaxation of stresses in the walls and the bottom.

• The minimum principal stress (S3) contours show a complete relaxation of stresses around the walls, the bottom, and the roof. Therefore, no tensile stress problems are revealed.

• The strength factor (SF) is higher than 1.0 around the walls and roof, with only the bottom presenting values close to 1.0. However, there is a concentration of shear and tension yielding points. Yielding points reach up to 1.3 ft over the roof and 2.6 ft around the walls.

• Displacement (D) contours show a maximum >1 cm in the walls and bottom.

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Figure 13-13: Modeling Results for Decline Ramp; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements

Source: GMS, 2020

The results for Topcut A (Figure 13-4) indicate the following:

• In general, the maximum principal stress (S1) contours show high compressive stresses on the shoulders and a relaxation of stresses in the walls, the bottom, and the roof;

• The minimum principal stress (S3) contours show a zone with tensile stress on the shoulders and relaxation of stresses around the walls, the bottom, and the roof. Therefore, no major tensile stress problems are revealed;

• The SF is higher than 1.0 around the walls and roof, with only the bottom presenting values close to 1.0. However, there is a concentration of shear and tension yielding points. Yielding points reach up to 1.2 ft over the roof and 1.0 ft around the walls;

• Displacement (D) contours shown a maximum >1 cm in the walls, the bottom, and the roof.

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Figure 13-14: Modeling Results for Topcut A; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements

Source: GMS, 2020

The results for Undercut B (Figure 13-15) indicate the following:

• In general, the maximum principal stress (S1) contours show high compressive stresses on the shoulders and a relaxation of stresses in the walls, the bottom, and the roof.

• The minimum principal stress (S3) contours show a zone with tensile stress on the shoulders and a relaxation of stresses around the walls, the bottom, and the roof. Therefore, no major tensile stress problems are revealed.

• The SF is higher than 1.0 around the walls and roof, with only the bottom presenting values close to 1.0. However, there is a concentration of shear and tension yielding points. Yielding points reach up to 2.0 ft over the roof and 1.2 ft around the walls.

• Displacement (D) contours shown a maximum > 1 cm in the walls, the bottom, and the roof.

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Figure 13-15: Modeling Results for Undercut B; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements

Source: GMS, 2020

The results for Undercut C (Figure 13-6) indicate the following:

• In general, the maximum principal stress (S1) contours show high compressive stresses on the shoulders and a relaxation of stresses in the walls, the bottom, and the roof.

• The minimum principal stress (S3) contours show a zone with tensile stress on the shoulders and relaxation of stresses around the walls, the bottom, and the roof. Therefore, no major tensile stress problems are revealed.

• The SF is higher than 1.0 around the walls and roof, with only the bottom presenting values close to 1.0. However, there is a concentration of shear and tension yielding points. Yielding points reach up to 2.5 ft over the roof and the bottom, and 1.2 ft around the walls.

• Displacement (D) contours shown a maximum >1 cm in walls, the bottom, and the roof.

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Figure 13-16: Modeling Results for Undercut C; a) Major Principal Stress, S1; b) Minor Principal Stress, S3; c) Strength Factor, SF; d) Displacements

Source: GMS, 2020

To optimize the mine design and mine plan, a three-dimensional model considering finite difference (Figure 13-17) was developed using the Flac 3D v.5.01 Program (Itasca, 2015).

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Figure 13-17: Three-Dimensional Model of Finite Difference

Source: GMS, 2020

The model was developed to perform the parametric analysis of the mine design and mine plan according to the excavation and backfill process for the LOM. In addition, potential caving on surface was assessed using the model results.

Excavation of adjacent drifts could not only result in loss of backfill strength, it could also generate high levels of stress, resulting in rock mass damage and possible poor excavation performance related to low-strength rock mass. Maintaining at least three horizontal drifts of distance between excavations would help to cut off the horizontal stresses acting across the deposit.

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Rock mass damage will be particularly prevalent in the excavation intervals located within the fault zones adjacent to advancing drifts. These cross-cut intervals will need to be well supported during initial development and may need rehabilitation in the more critical closure areas.

In general, the reduction in the mining stresses around excavations is more likely to adversely affect the stability of the areas immediately above the cut and fill mining areas. The failure modes in these areas are likely to be tensile failure and gravity-induced unravelling. Preventing these types of failure will require high levels of support.

FLAC3D code was specifically used to review the potential for movement along faults and the potential for surface subsidence. The excavation and backfilling sequences generate accumulated displacements of around 11–15 inches over the levels facing the north orientation of the mine. These displacements are considered the maximums identified in the global excavation of the model and represent a contour area of at least five levels higher. In spite of the maximum displacements identified, the displacements are expected to be overestimated because the numerical analysis was modelled considering year-by-year excavation that strongly affects the rock mass displacement values. Therefore, the monthly excavation may present lower displacement values.

Subsidence caused by extraction could cause dilation or fracturing above the deposit and an increase in hydraulic conductivities and water inflows to the mine. Some level of dilation of fault and joint systems within the Grassy Mountain Formation can be expected as a result of mining. Under the current extraction sequence, this is expected to occur during the initial stages of mining. The ground surface presents contour displacements of around 0.4–9.8 inches from year 1 to year 5 (increasing in lineal proportion), but from year 5 to year 8, the contour displacements are projected to stabilize at around 9.8 inches.

GMS noted the following:

• Based on the prevailing ground conditions in the Poor rock conditions, cut and fill headings are recommended (30 ft wide x 15 ft high maximum dimension stope allowed). These dimensions will ensure that good quality backfill practices can be maintained through tight filling to manage open spans, side wall stability, and ultimately the stability of the mining area. Smaller spans will require less ground support to ensure that cycle times and productivity are maintained.

• The stand-off distance for long-term critical excavations, including decline ramp and ventilation shafts, is recommended to be 200 ft from the drifts. For permanent foot wall drives, a 100 ft stand-off is recommended.

To ensure stability during the mine sequence, lateral rock pillars should be wider than three drifts wide. These rock pillars known as Rib Pillar, also maintain control of mining and reduce possible high stress concentrations around the drifts in mining and backfilling process. This is primarily dictated by the potential range of Fair–Poor rock mass conditions (especially near faulted areas).

GMS considers that the best approach to manage risk in this environment is to plan a more conservative approach to the drift design and extraction sequence. The high-grade nature of the deposit means that ore recovery is critical to maintaining the grade profile, and the stability and final recovery of drifts in the variable rock mass could be very challenging.

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13.5.1  Ground Support

The ground support design considers industry-standard empirical guidelines and GMS’s experience in variable ground conditions. The ground support philosophy for underground excavations is sprayed concrete lining (fiber-reinforced shotcrete) with bolts installed through the concrete. Sprayed concrete was selected for overall simplicity and speed of application, longevity of surface support, and sealing of rock blocks that may potentially fall from the roof and walls.

Enhanced ground support for poor ground areas includes the installation of initial (pre-support), thicker shotcrete, reduced bolting spacing, and Swellex-type bolting. Cable bolts are considered for over-stressed accesses, cross-cuts in cut and fill areas, and drifts under rock mass environments (particularly the roof). Table 13-9 and Table 13-10 provide the support designs under rock mass and backfill environments, respectively.

Table 13-9: Reinforcement and Support Design for Mine Development Under Rock Mass Environment

Excavation		Section (ft)		Bolts Length(ft)		Bolts Pattern (ft)				Cable Bolts (ft)		Cable Pattern (ft)				Fiber-Reinforced Shotcrete (Inches)				Mesh (1)
Decline		15		7.9			4.3 x 4.3			No			8.2 x 8.2				4				Yes
Access (top)		15		7.9						19.7
Access (under)		15		7.3						No											No
Topcut A		15		7.9						19.7
Undercut B		20		8.4(2)						19.7
Undercut C		30		9.3(2)						19.7

Note: (1) Galvanized welded wire mesh. (2) Final length should be defined in-situ by geotechnical engineer on site according to Boltec equipment to use (at this stage was necessary to use 7.9 ft. length as maximum bolt length).

Table 13-10: Reinforcement and Support Design for Mine Development Under Backfill Environment

Excavation

Section (ft)

Bolts Length (ft)

Bolts Pattern (ft)

Cable Bolts (ft)

Cable Pattern (ft)

Fiber-Reinforced Shotcrete (inches)

Mesh (1)

Topcut A (3)

15

7.3

4.3 x 4.3

No

No

2

No

Undercut B (3)

20

7.5

Undercut C (3)

30

8.0(2)

Note: (1) Galvanized welded wire mesh. (2) Final length should be defined in-situ by geotechnical engineer on site according to Boltec equipment to use (at this stage was necessary to use 7.9 ft. length as maximum bolt length). (3) Shotcrete and bolts in rock walls (not at CRF roof and/or walls).

Long-standing temporary development, over-stressed accesses, and cross-cuts in closure areas would require some level of rehabilitation. This has been estimated as at least 30% of cross-cuts (in Poor and Fair–Poor rock conditions). A rehabilitation requirement for permanent development should also be considered and estimated based on the linear feet of development completed in Poor rock conditions (mainly close to the North fault and the Grassy fault).

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13.5.2  Ground Monitoring Program

Due to the rock quality and strength issues summarized in Sections 13.2 and 13.2.7, it will be necessary to install rock stability monitoring instrumentation in the Grassy Mountain underground workings to monitor the geotechnical behavior of pillars in the different mined areas and backfilled areas. The configuration considers that data collection will be manual and continuous, and its ongoing interpretation will be the responsibility of the mine operation. The instrumentation may be installed as the lower levels are developed and should focus on measuring the deformations and stresses that may develop during mining operations.

The Grassy Mountain instrumentation program will consider, at least, the following:

• Underground monitoring:

• Geotechnical inspections and permanent ground control during the operation.

• Preparation of procedures for systematic convergence and stress changes measurements.

• Topographic monitoring using total station, where the convergence of the decline ramp and drifts development will be surveyed through the laser scanner.

• Deformation monitoring using a tape extensometer, measuring stations every 98 or 164 ft, depending on visual availability. This monitoring will be correlated with the topographic monitoring.

• In-situ stress testing using overcoring. This will indicate those sectors subject to significant changes in compression or relaxation due to stress redistribution during drift mining. This will be done twice a year by an external service to update the in-situ stress condition.

• Surface monitoring:

• Visual inspection of settlements and/or cracks on the surface.

• Cross-crack measurements, either manual or by wireline extensometer.

• Topographic monitoring using total station, where the surface deformation above the mine operation will be measured monthly through an on-site prism network.

• Satellite InSAR monitoring to measure the surface deformation of the general arrangement, especially the possible subsidence above the underground portion of the mine. This will be an external service performed once a year, and the measures will be correlated with the topographic measuring above the mine.

13.5.3  Global Extraction Sequence

The mine should be programmed with fast drifts advances, keeping the initial support to the excavation face, the reinforcement, and the final support at 40 ft as the maximum allowed. The backfill should be installed in reverse and according to schedule, to avoid damage from side drifts excavation, that affects its strength and/or its attachment to the bedrock.

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Special care should be taken of stability as excavations advance in areas where the North and Grassy faults are present and in the area between them, due to the Poor quality of the rock mass conditions. Sub-parallelism between drifts and these faults result in slow excavations under poor geotechnical conditions with a high risk of instability in roofs and walls during excavation, according to the trace of the fault. In general, the deposit presents this sub-parallelism condition for the mine design, so it is estimated to be a general operational condition for the mine.

If considered, the presence of a water surface in the upper levels of the mine is an additional variable to the probable instability conditions in the drifts, so it will be necessary to implement and maintain a rigorous operation.

Compromises have been made in the extraction sequence as a result of the need to balance grade and production profiles, extraction of wide orebody areas, and other geotechnical constraints. Ultimately, some aspects of the sequence may not be geotechnically optimal, and additional analyses or designs may be required.

13.6  Portal Design

The portal excavation and soft ground tunneling design was initially done by Ausenco during the 2018 PFS and its stability checked by GMS during the Consolidated Permits stage.

The portal is designed to allow access to the underground mine facilities while providing adequate space for equipment and vehicles. It will be located uphill and approximately 750 ft south of the primary crusher, at an approximate elevation of 3,749 ft. The portal pad was designed with a 1% inclination toward outside, to allow storm water to flow away from the portal and toward the storm water drainage ditches. The portal pad will have sufficient space to install the required ventilator infrastructure to be used during the excavation of the decline ramp, construction facilities, and to allow the safe transit of the development equipment. The pad area was expanded from the initial area designed during the Consolidated Permits process to allow more space for facilities. In addition, the general cut design was updated, increasing the total area of the portal and the excavation volume.

The portal will have a waste rock excavation volume of 1,120 kft³, which will be transported and disposed of in the waste rock dump facility designed for the mine operations.

Weak rock mass ground conditions at the portal require that a shallow box-cut excavation be established to form a suitable face where tunneling can occur. Specialized soft ground tunneling techniques with full rock reinforcement and support will then be required to advance the tunnel for an approximate 33 ft decline distance, to a point where conventional drill and blast tunneling can begin.

The current design is considered suitable for the feasibility level. Additional work has been proposed to bring the design to construction level, including a numerical modeling of the excavation sequence to be completed prior to the start of pre-construction. Then, during construction perform site investigations such as bench geotechnical mapping, portal slope re-design (if necessary), and numerical re-modeling of the excavation.

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13.7  Grade Control

The grade control will be done by the geologist daily. The geologist will collect samples from all producing stopes and send them to an assay laboratory. The assay grades will be compared to the anticipated grades in the resource block model to monitor the accuracy of the model and maintain the desired head-grade.

When a production stope gets within two rounds of the design, the stope will go on grade control. When a stope is on grade control, every round must be sampled before the next round can be drilled. The stope may end prematurely or extend past the design if the assayed grade is below or above the cut-off grade.

13.8  Personnel

Please refer to Section 18.2.2.1 for underground personnel requirements.

13.9  Development Design

13.9.1  Mine Design Parameters

The Grassy Mountain orebody will be accessed using a 15 x 15 ft main decline, developed from a portal on surface. The decline will provide the connection to all services. The design intent is to have the decline located as close as possible to the mineralization in order to reduce transportation costs but sufficiently removed from mining activities to ensure that the decline is geotechnically stable for the planned LOM. A summary of the mine design criteria is shown in Table 13-11.

Table 13-11: Mine Design Parameters

Design Parameters		Width (ft)		Height (ft)		Diameter (ft)		Length (ft)		Maximum Gradient (%)
Decline		15		15		NA		varies		15
Level access		15		15		NA		varies		12.5
Power station		15		15		NA		50		0
Level station		15		15		NA		105		0
Stockpile		15		15		NA		50		0
Sump		15		15		NA		50		12
Truck loading bay		15		15		NA		50		0
Ventilation bay		15		15		NA		varies		0
Ventilation raise		NA		NA		12		varies		vertical
Topcut A		15		15		NA		varies		0
Undercut B		20		15		NA		varies		0
Undercut C		30		15		NA		varies		0
Decline turning radius		NA		NA		100		NA		NA

Note: NA = not applicable.

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13.9.2  Level Access

The level station will have a standoff distance from the orebody of approximately 300 ft. This distance is determined by the maximum gradient of the level access of 12.5%, the geometry of accessing five levels for every one level station, and the geometry of the orebody as shown in Figure 13-18. Therefore, the standoff distance of 300 ft varies slightly depending on these inputs.

Figure 13-18:  Level Access Layout (Looking North)

Source: MDA, 2020 and used unmodified by RESPEC, 2026

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13.9.3  Station Design

There are five stations planned for the mine. Each station will access up to five production levels. The stations will be on the following levels: 3420, 3360, 3285, 3210, and 3135. Each station is to be accessed via the decline. Each station will have a truck loading bay, power bay, ventilation access, stockpile, sump, and level access as shown in Figure 13-19.

Figure 13-19: Station Design

Source: MDA, 2020 and used unmodified by RESPEC, 2026.

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The truck loading bay will be used to load trucks with load–haul–dump (LHD) vehicles. The power bay will be used to store the mobile load center. The ventilation access will connect on each station via the vent raises. The sump is designed at a -12% gradient and will be used to collect mine water. The stockpile will be used to store material until it can be loaded into trucks. The level access will provide access to the production stopes.

13.10  Equipment Selection

Mine operations will be based on the usage of mobile mining equipment suitable for underground mines. The estimate of the fleet size was based on first principles and equipment running-time requirements to achieve the mine production plan. The estimate of the running time for the mine equipment was conducted through the usage of mine-operating factors. Maximum permanent equipment quantities are summarized in Table 13-12.

Table 13-12: Mining Mobile Equipment List

Mining Mobile Equipment		Model		Quantity
Dual (drill + bolter)		Sandvik DD422i		3
LHD		Sandvik LH307		4
Truck with ejector bed		Sandvik TH320		3
Diamond drilling		Hydracore HC200UG		1
Shotcrete sprayer		GetMan Proshot Concrete Sprayer		1
Shotcrete truck		GetMan ProMix 6		1
Lube truck		Getman A64 SE Lube		1
Water truck		Getman A64 SE Water Sprayer		1
Scissor Lift		Getman A64 SE SL		2
Transportation – Tractor		Kubota 5100		4
Front-end loader		CAT 962H		2
Telehandler		CAT TL1255		2
Dozer		CAT D6T		1
Motor grader		CAT 160		1
4WD twin cab truck		Ford F-350		3
Mine rescue truck		Kovatera KT200		1

13.11 Production and Development Productivity Assumptions

13.11.1  Drilling and Bolting

Production and development drilling and bolting will be done using three Sandvik DD422i as shown in Figure 13-20. This unit can setup in a heading and bolt the back and then drill the face all in one setup. Drilling and bolting productivities were built up from first principles and vary by heading profile. The results from the first principles are summarized in Table 13-13 and Table 13-14. The bolting requirements were determined from the geotechnical analysis.

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Figure 13-20:  Sandvik DD422i

Source: Sandvik website, 2026

Table 13-13:  Drilling First Principles Assumptions

Drilling		Units		Development				15 Topcut				20 Undercut				30 Undercut
Penetration rate		ft/min			4.0				4.0				4.0				4.0
Effective time		%			80	%			80	%			80	%			80	%
Penetration rate		ft/min/eff			3.2				3.2				3.2				3.2
Non-drill time		min			90				90				90				90
Hole length		ft			12				12				12				12
Holes per round		holes			53				50				61				85
Length per round		ft			636				600				732				1,020
Time per round		min/rd			289				278				319				409
Time per round		h/rd			4.8				4.6				5.3				6.8
Operating hours per shift		h			10				10				10				10
Rounds per shift		rd/shift			2.1				2.2				1.9				1.5
tons per round		tons/rd			161				179				239				359
tons per hour		tons/hr			33				39				45				53

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Table 13-14:  Bolting First Principles Assumptions

Bolting		Units		Development				15 Topcut				20 Undercut				30 Undercut
Bolting rate		bolts/min			0.2				0.2				0.2				0.2
Effective time		%			80	%			80	%			80	%			80	%
Bolting rate		bolts/min			0.16				0.16				0.16				0.16
Non-bolting time		min			45				45				45				45
Bolts per round		bolts/rd			33				37				43				50
Time per round		min/rd			251				276				314				358
Time per round		h/rd			4.2				4.6				5.2				6.0
Operating hours per shift		h			10				10				10				10
Rounds per shift		rd/shift			2.4				2.2				1.9				1.7
tons per round		tons/rd			161				179				239				359
tons per hour		tons/h			38				39				46				60

13.11.2 Shotcrete

Production and development shotcrete will be sprayed using a GetMan Proshot Concrete Sprayeras shown in Figure 13-21.

Figure 13-21: GetMan Proshot Concrete Sprayer

Source: Getman website, 2026

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The haulage of the shotcrete will be done using a GetMan ProMix 6 as shown in Figure 13-22.

Figure 13-22: GetMan ProMix 6

Source: Getman website, 2026

Shotcrete sprayer productivities were built up from first principles and vary by heading profile. The results from the first principles are summarized in Table 13-15. The transmixer productivities are based on ton*miles. The distances used for the ton*mile calculation are shown in Figure 13-1.

Table 13-15: Shotcrete First Principals Assumptions

Shotcrete Spray		Units		Development				15 Topcut				20 Undercut				30 Undercut
Shotcrete rate		ft3/min			2.5				2.5				2.5				2.5
Effective time		%			80	%			80	%			80	%			80	%
Shotcrete rate		ft3/min			2				2				2				2
Non-shotcrete time		min			30				30				30				30
Shotcrete per Round		ft3/rd			134				150				167				202
Time per round		min/rd			97				105				114				131
Time per round		h/rd			1.6				1.8				1.9				2.2
Operating hours per shift		H			10				10				10				10
Rounds per shift		rd/shift			6.2				5.7				5.3				4.6
tons per round		tons/rd			161				179				239				359
tons per hour		tons/hr			100				102				126				164

Note: rd = round.

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Figure 13-23: 3360 Shotcrete Thickness (units in inches)

Source: RESPEC, 2026

The location and thickness of shotcrete was based on geotechnical recommendations:

• All long-term development will receive 4 inches of shotcrete

• All access drifts will receive 4 inches of shotcrete

• All stope accesses not under backfill will receive 4 inches of shotcrete

• All stope accesses under backfill will receive 2 inches of shotcrete on the ribs.

An example of the shotcrete application is shown in Figure 13-23.

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13.11.3  Blasting

ANFO will be used for most production blasting and development rounds. Boosters, primers, detonators, detonation cord, and other ancillary blasting supplies will also be required. Explosives will be stored in a secure powder magazine in accordance with current applicable explosives regulations.

Once the drilling cycle is complete, the blasting agent will be loaded into the holes with the respective nonel blasting cap and booster. The timing of the round with the nonel caps is extremely important as it is critical to pulling the maximum amount of distance per round.

Blasting will occur on-demand throughout the shift. Before blasting occurs, any affected areas will be cleared of personnel, and the blasting location will be announced over the mine communication system. After the blast, an appropriate amount of time must pass to provide adequate ventilation to any affected areas before mining can resume. Blasting productivities were built up from first principles and vary by heading profile. The results from the first principles are summarized inTable 13-16.

Table 13-16: Blasting First Principles Assumptions

Blasting		Units		Development				15 Topcut				20 Undercut				30 Undercut
Loading rate		ft/min			8				8				8				8
Effective time		%			80	%			80	%			80	%			80	%
Loading rate		ft/min			6.4				6.4				6.4				6.4
Non-blasting time		min			30				30				30				30
Hole length		ft			11				11				11				11
Holes per round		Holes			52				49				60				84
Length per round		ft			546				515				630				882
Time per round		min/rd			115				110				128				168
Time per round		h/rd			1.9				1.8				2.1				2.8
Operating hours per shift		h			10				10				10				10
Rounds per shift		rd/shift			5.2				5.4				4.7				3.6
tons per round		tons/rd			161				179				239				359
tons per hour		tons/h			84				97				112				128

13.11.  4 Mucking

The Sandvik LH307 underground loader as shown in Figure 13-25 with a nominal 4.8 cubic yard bucket capacity will be used for all underground loading activities.

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Figure 13-24: Sandvik LH307 Underground Loader

Source: Sandvik website, 2026

Backfill placement will also be done using the same loader except the bucket will be replaced with a push plate. The blasted material will be transported to the underground stockpile located on the level station using the loader. The material will then be loaded into haul trucks at the truck loading bay using the same loader. The material will then be transported to surface. The truck loading bay intersection will be excavated to a height of 16 ft to provide clearance to load the trucks.

13.11.5  Hauling

The haulage fleet will use Sandvik TH320 trucks as shown in Figure 13-26.

Figure 13-25: Sandvik TH320 trucks

Source: Sandvik website, 2026

The Sandvik TH320 AT AD22 truck is a conventional low-profile underground-mining trucks. The haul trucks will be equipped with an ejector bed for the use of dumping backfill in the headings. Trucks will be loaded at the truck loading bay. The trucks will transport the material to surface. Once unloaded on the surface, the trucks will be loaded at the backfill plant on surface and haul the backfill underground to a location that is undergoing backfilling.

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Hauling productivities were built up from first principles. The results from the first principles are summarized in Table 13-19.

Table 13-17: Haulage First Principles Assumptions

Haulage		Unit		Development				15 Topcut				20 Undercut				30 Undercut
Truck Size		tons			30				30				30				30
Average Haul Dist One Way		ft			9,940				9,940				9,940				9,940
Average Haul Dist One Way		miles			1.90				1.90				1.90				1.90
Average Haul Dist Round Trip		miles			3.80				3.80				3.80				3.80
Average Speed		mph			6				6				6				6
Time for 1 trip		h			0.63				0.63				0.63				0.63
Number of Trips Per Round		trips/rd			6.00				6.00				8.00				12.00
Time Per Round		min/rd			228				228				304				456
Time Per Round		h/rd			3.8				3.8				5.1				7.6
Operating Hours Per Shift		H			10				10				10				10
Rounds Per Shift		rd/shift			2.6				2.6				2.0				1.3
tons Per Round		tons/rd			161				179				239				359
tons Per Hour		tons/h			42				47				47				47
tons*Mile Per Hour		tons*miles/h			180				180				180				180

Ore that is hauled to surface will be placed in the ore stockpile. A front-end surface loader will feed the ore from the stockpile into the primary crusher. Waste rock hauled to surface will be dumped at a waste-rock storage facility. The tonnage of waste hauled to surface over the LOM is summarized in Figure 13-28. This waste will be fully utilized over the mine life as cemented rock-fill material, reducing the total amount of borrow material required over the mine life.

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Figure 13-26: Waste Haulage by Year

Source: RESPEC, 2026

13.11.6  Backfilling

Stopes are planned to be backfilled with CRF that will provide confinement on the stope walls.

The backfill method was selected based on the geological and geotechnical conditions of the deposit, as well as the selected mechanized cut and fill mining method. The main objectives of the backfill is to provide stability to the drifts and to control dilution associated with ore extraction.

Rock from a borrow pit close to the mine will be used as aggregate. An LHD equipped with a jamming boom and push plate will be used to place the CRF into the drifts.

Laboratory tests were conducted to define the CRF strength. For that, a testing plan was prepared for 12 CRF samples. The entire program involved different phases such as:

• Sieve analysis of the aggregate

• Mixing of samples with two different compositions

• Casting or molds preparation

• Curing process

• Mechanical properties measurements: laboratory testing.

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The sieve analysis of the aggregate was conducted by PACS Laboratory. Approximately 1,392 kg of GM-1mix and 1,392 kg of GM-2 mix were sieved separately and entirely. The aggregate was tested in the “as received” moisture content condition with no drying or washing. Testing was conducted in general accordance with ASTM D-422 Particle Size Analyses of Soils and as specified by the testing plan on the following sieves:

• 3 inch (75 mm)

• 2 inch (50 mm)

• 1 ¹⁄₂ inch (37.5 mm)

• 1 inch (25.0 mm)

• ³⁄₈ inch (19.0 mm)

• ³⁄₈ inch (9.5 mm)

• Number 4 (4.75 mm)

• Number 10 (2.0 mm).

The aggregate used was compared using Talbot grading. The material used was rock Basalt from a borrow pit near the mine. The material was crushed to less than 4” and sent to MetaRock Laboratories in two (2) bag packages. The results show that the distribution is similar to the Talbot grading. Talbot and Richard (1923) proposed a general equation for combined (fine and coarse) regularly graded aggregate. Swan (1995) suggested that the Talbot grading equation can be used to make an optimal grading of waste rock for CRF design.

In general, for a CRF application, a particle size >10 mm is classified as a coarse aggregate, while a particle size of <10 mm is defined as a fine aggregate.

The UCS testing program included 12 samples with a diameter of approximately eight inches and an approximate length of 16 inches. The design cement percentages were 5% and 7%, both proper percentages used for CRF backfill in mining industry. The design curing times were 14 and 28 days, according to the standard curing time for concrete. Table 13-20 summarizes the CRF mix recipe prepared for UCS testing.

Table  13-18: CRF Mix Recipe for UCS Testing

Mix ID		GM-1		GM-2
Aggregate size		<2 mm to 51 mm		<2 mm to 51 mm
Cement % by weight		5		7
Aggregate for 2.79 ft3 CRF (lb) (material from Sample 2, under 2 inches)		313.80		313.80
Sand for 2.79 ft3 CRF (lb) (fine material from Sample 2, under 10 mesh)		47.07		43.93
Cement for 2.79 ft3 CRF (lb)		18.04		25.04
Water for 2.79 ft3 CRF (gal) (water/cement = 1.2)		2.59		3.60
Estimate fresh CRF mix density (g/cm3)		2.30		2.37

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The mixing, casting and curing processes are shown in Figure 13-29.

Figure 13-27: Mixing, Casting and Curing Process

Note: MetaRock Laboratories, 2020 (Rock Mechanics Testing Report for – CRF Testing. Houston, Texas).

The following CRF capacities and strength results were obtained (Figure 13-30):

• 3.9 to 5.3 MPa of CRF strength with 7% of cement content and 14 days of curing

• 5.2 to 6.1 MPa of CRF strength with 7% of cement content and 28 days of curing

• 1.8 to 2.4 MPa of CRF strength with 5% of cement content and 14 days of curing

• 3.0 to 3.2 MPa of CRF strength with 5% of cement content and 28 days of curing.

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Figure 13-28: UCS Results vs Curing Time

Source: MetaRock Laboratories, 2020 (Rock Mechanics Testing Report for – CRF Testing. Houston, Texas).

Samples with low fines content and large particle concentration, which make rock contact possible, produce a weak zone of failure. A large particle size concentration can sometimes reduce the strength of CRF. A good relationship between sample density and strength was also found; therefore, a denser CRF with a low content of large particle sizes could have higher strengths.

Future work is required to assess the response of samples composed of 3% cement and 2% fly ash, and 4% cement and 3% fly ash, in order to compare these test results with the results of 5% and 7% cement, respectively.

As part of the 2026 Feasibility Study Update, GMS reviewed the updated mine layouts, extraction sequencing and production schedule provided by RESPEC. Based on the review completed, no material changes were identified that would require modification of the backfill design criteria, backfill performance assumptions or backfill sequencing strategy presented in this section.

13.11.7  Backfill Plant

An Simem WB100 backfill plant, as shown in Figure 13-29, will be constructed near the portal.

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Figure 13-29: Simem WB100 Backfill Plant

Source: SIMEM, 2026

The waste rock from underground operations will be used for CRF. Additional rock will be excavated and crushed from the surface borrow area. Cement and other supplies will be provided by local suppliers. The plant will produce approximately 3.27 cubic yards per batch and will require 2 minutes per batch or approx. 2,970 tons per day. The maximum amount of backfill required on a single day in the mine plan is 1,200 tons. The plant is oversized to ensure that the backfill plant will not be a bottle neck in the mining operation. This plant will also meet the requirement of shotcrete for ground support.

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It is assumed that the truck haulage fleet will get loaded with material underground and haul the material to surface. After the haul truck dumps the material on surface the haul truck will be loaded on surface with backfill. Each truck will require four batches of backfill from the backfill plant to be fully loaded. The haul truck will haul the backfill underground and place it in a backfilling location. To summarize, the haul trucks will be loaded with underground material on the way out of the mine and be loaded with backfill on the way into the mine. This is referred to as “round-haul”. The backfilling assumptions are the same as the haulage assumptions in table 13-20.

13.11.8  Production Scheduling

The scheduling approach utilizes following production calendar, rates, and limits. These resources were assigned to each mining tasks and mine schedule was developed utilizing these parameters. The calendars applied, production rates, and production limits are shown in tables below.

Table  13-19: Calendars by Crew

Crew		Hours Per Day		Days Per Week
Production mining		24		Mon–Thurs (4)
Production backfilling		24		Mon–Thurs (4)
Contractor development		24		Mon–Sun (7)
Contractor raise bore		24		Mon–Sun (7)

Table 13-20: Production Rates

Name		Quantity		Unit
Lateral development rate		18		ft/d
Vertical development rate		2		ft/d
Production rate		30		ft/d
Backfill rate		800		t/d

Limits were placed on production fields. The limits were based on the first-principle productivity rates, and the mill capacity and the shotcrete plant capacity. The limits are shown in Table 13-21.

Table 13-21: Production Limits on Production Fields

Production Field		Limit		Unit
Economic material		1,600		t/d
Truck haulage		65,500		ton*mile/month
Transmixer haulage		5,500		ton*mile/month
Drill and Bolter equipment hours		72		h/d
Mucking equipment hours		96		h/d
Blasting equipment hours		24		h/d
Shotcrete sprayer equipment hours		24		h/d
Shotcrete volume		1,100		cubic ft/d

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13.12  Underground Infrastructure and Services

13.12.1 Ventilation

The ventilation network was designed to comply with U.S. ventilation standards for underground mines (Code of Federal Regulations/Title 30. Underground metal and nonmetal mines. Washington, DC: U.S. Government Printing Office, Office of the Federal Register). Regulatory concentrations for gases are specified by the 1973 American Conference of Industrial Hygienists (ACGIH) threshold limit values (TLVs) [71 Fed. Reg. 3 28924 (2006)]. For diesel particular matter (DPM), a permissible exposure limit (PEL) of 160 µg/m³ total carbon is specified in the U.S. diesel rule for metal/nonmetal mines (71 Fed. Reg. 28924 (2006)).

The Mine Safety and Health Administration (MSHA) sets an airflow requirement for the dilution of gas emissions, and an additional airflow requirement for dilution of DPM. These values are published with the list of approved engines on MSHA’s internet website. Airflow of 100,000 cubic feet per minute (cfm) was selected as a minimum reference for the ventilation design of each level to meet the MSHA ventilation standards. A mine ventilation network design was built using the VentSim software package as shown in Figure 13-31 and Figure 13-32.

As part of the 2026 Feasibility Study Update, RESPEC reviewed the updated mine layouts and production schedule. Based on the review completed, no material changes were identified that would require modification of the ventilation requirements and system presented in this section.

Figure 13-30: Ventilation Network (isometric view looking west)

Note: No modifications made in 2026 FS update. Source: MDA, 2020

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Figure 13-31: Ventilation Network (Section View Looking Northwest)

Note: No modification made in 2026 FS update. Source: MDA, 2020

Figure 13-32: Surface Ventilation Fan (Section View)

Source: Spendrup, 2026

Required airflows were determined at multiple stages during the mine life, using equipment numbers and utilization rates, specific engine types and exhaust output, and the number of personnel expected to be working underground. The designed ventilation system includes the following parameters:

• Main fan total pressure of 12 inches of water gauge

• Main fan air flow of 467,000 cfm

• Main fan power of 500 hp

• Each active level air flow of 100,000 cfm

• Only three active levels at any given time

• Air density of 0.0722 lb/ft³.

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The planned ventilation will use a push/pull system and will require one exhaust fan on surface. A raise bore will be used to construct ventilation raises between level stations and connecting to the surface fans as shown in Figure 13-34.

Figure 13-33: Design of Vent Raises

Source: MDA, 2020 and modified by RESPEC in 2026.

Each vent raise will have a diameter of 12 ft. Each raise will be steel lined and have an escape ladder. Auxiliary fans will take air from the main circuit and push the air to the working face on the level using vent ducting and vent bag. Each level will have an auxiliary fan at the level station.

13.12.2  Underground Dewatering

Water will be needed for underground production drilling, bolting, shotcrete, and diamond drilling. The required LOM water supply has been estimated based on the mine-equipment requirements as summarized in Table 13-24.

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Table 13-22:  Estimated Underground LOM Water Requirement

Equipment		Quantity		Water Requirements (gpm)		Operational Factors		Water Required (gpm)
Sandvik DD422i Drill		3		49		70%		103
Diamond Drill		1		20		70%		14
GetMan Proshot Concrete Sprayer		1		10		70%		7
Total Required								124
Factor								20%
Total with factor								150

Water at the face will be pumped to the station sump. From the station sump the water will either be used for equipment water supply or pumped out to the plant for use in the process circuit. When used for equipment water supply, the sediments will be removed at the station sump. Excess water at the station sump will be pumped up to the next station sump. The water will continue to be pumped up to the next station until it is pumped out of the mine

The connection between sumps will be a steel pipe in the ventilation raise. The report titled “Grassy Mountain Gold and Silver Project Mine Dewatering Hydrogeologic Assessment” by Lorax Environmental Services (March, 2020) states the following: “The total estimated range of inflow rates is 12 US gpm to 78 US gpm.” The dewatering system was designed for 250 gpm which will accommodate both the max inflow rates (78 gpm) and the equipment water requirements rates (150 gpm) in the event that water is not recirculated to the equipment.

13.12.3 Underground Power

An underground 480 V transformer will be placed near the entrance to the portal at the start of mining. This will supply power to electrical equipment used to develop the main decline and to portable fans. A main power line will be installed along the rib of the decline to carry 1.4 kV when development has advanced far enough that carrying power at 480 V becomes too inefficient. This line will be connected to a transformer that will be moved underground. Line power will also be extended to the locations of the two ventilation shafts to supply power to the ventilation fans.

Both transformers will be placed underground in power bays. The transformers will be moved to other power bays depending on the location of the mining activities.

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Figure  13-34: Mine Load Center (1000 kVA)

Source: Intermountain Electronics, Inc., 2026

13.12.4  Underground Communications

Inside the mine, a leaky-feeder very high frequency (VHF) radio system will be used as the primary means of communication. The system will allow for communications between the underground mine and surface operations.

13.12.5  Underground Refuge and Escape Ways

Two emergency refuge stations will be necessary in case of fire or rockfalls that would block access and prevent full evacuation of personnel. These refuges will allow the staff to remain safe in the underground mine for 36 hours. The refuge stations are mobile, each can accommodate up to 16 people within the protected chamber. They will be located strategically from where the mine operation personnel are located. Figure 13-36 shows an example of a refuge station.

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Figure 13-35: Mobile Refuge Station

Note: Sixteen-person units are used for the 2026 update. Source: MDA, 2020, after MineARC, 2020

All vent raises will be steel lined and equipped with an escape way ladder for secondary evacuation. The primary route for evacuation will be the decline. The secondary route for evacuation will be the vent raises.

13.13 Mining Costs

Mining costs are summarized in Section 18.

13.14 Life-of-Mine Production

The QP used the Proven and Probable Mineral Reserves to create a mining production schedule using Deswik Scheduler, which allows for the scheduling of both underground development and production. The primary inputs used to develop the schedule include:

• The resource block model with defined material types

• Development centerlines drawn in the direction of mining

• Solids representing the stopes or production areas to be mined

• Attributes to define activity types, material types, profiles, etc.

• Mining sequence among developments and production areas

• Development and production rates by location

• Definition of the periods to be used.

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The naming convention for material types considered either ore or waste. Ore was assigned to two categories based on grade: high-grade or low-grade. High-grade is material that is above the economic cut-off grade. Low-grade is material that is below the mining economic cut-off grade, but above the mill cut-off grade. The basic assumption is that a stope that is economic to be mined will be processed in its entirety. Thus, if internal waste in an economic stope is classified as Measured or Indicated Mineral Resources, these resources will be converted to Proven or Probable Mineral Reserves, respectively, and will contribute to the revenue stream.

Waste comprises:

• Material classified as Measured or Indicated Mineral Resources that is below both the mining cut-off grade and the mill cut-off grade.

• Material classified as Inferred Mineral Resources.

Waste is considered to be internal dilution within a stope, which would be mined and sent to the process plant. All waste material is considered to have zero grade and therefore does not contribute to the revenue steam.

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The final production schedule was calculated in Deswik Scheduler and then summarized in Excel. The mine production summary is presented in Table 13-25. The material to be sent to the mill is summarized in Table 13-26. The development schedule is summarized in Table 13-27.

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Table 13-23: Mine Production Summary

Year		0		1		2		3		4		5		6		7		8		9		10		Total
Mined Measured and Indicated Resource Above Cut-off Gradetons (tons x 1,000)		3		183		240		226		32		225		203		258		199		196		15		1,980
Grade (oz Au/ton)		0.277		0.187		0.217		0.208		0.217		0.217		0.234		0.174		0.158		0.181		0.126		0.199
Ounces (oz Au x 1,000)		1		34		52		47		50		49		48		45		31		36		2		395
Grade (oz Ag/ton)		0.282		0.264		0.292		0.273		0.312		0.294		0.279		0.319		0.308		0.314		0.255		0.295
Ounces (oz Ag x 1000)		1		48		70		62		72		66		57		82		61		62		4		585
Mined Measured and Indicated Resource Subgradetons (tons x 1,000)		2		29		30		29		33		26		20		22		19		15		1		226
Grade (oz Au/ton)		0.033		0.047		0.046		0.045		0.043		0.046		0.048		0.048		0.053		0.047		0.048		0.046
Ounces (oz Au x 1,000)		0		1		1		1		1		1		1		1		1		1		0		11
Grade (oz Ag/ton)		0.212		0.161		0.180		0.153		0.153		0.168		0.173		0.204		0.195		0.196		0.181		0.173
Ounces (oz Ag x 1000)		0		5		5		4		5		4		3		5		4		3		0		39
Total Mined to Stockpiletons (tons x 1,000)		5		212		269		255		265		251		223		280		217		212		17		2,207
Grade (oz Au/ton)		0.172		0.168		0.199		0.189		0.195		0.199		0.218		0.164		0.149		0.171		0.119		0.184
Ounces (oz Au x 1,000)		1		36		53		48		52		50		49		46		32		36		2		405
Grade (oz Ag/ton)		0.252		0.250		0.280		0.259		0.292		0.281		0.269		0.310		0.299		0.305		0.249		0.283
Ounces (oz Ag x 1000)		1		53		75		66		77		71		60		87		65		65		4		624
Total with Ore Loss & Dilutiontons (tons x 1,000)		5		226		287		272		284		265		240		298		234		227		19		2,358
Grade (oz Au/ton)		0.167		0.163		0.191		0.182		0.187		0.193		0.207		0.159		0.144		0.165		0.111		0.177
Ounces (oz Au x 1,000)		1		37		55		50		53		51		50		47		34		37		2		417
Grade (oz Ag/ton)		0.254		0.246		0.274		0.254		0.283		0.278		0.261		0.305		0.291		0.299		0.235		0.277
Ounces (oz Ag x 1000)		1		56		79		69		80		74		63		91		68		68		4		653
Waste
Waste tons (t x 1,000)		64		76		14		3		25		16		22		12		6		4		—		242
Backfill
Cemented Rockfill tons (tons x 1,000)		1		124		196		215		149		209		185		226		174		146		19		1,645
Footage
Lateral Footage (ft)		4,367		17,814		17,178		14,873		15,949		14,146		12,960		17,107		12,436		11,636		1,010		139,477
Vertical Footage (ft)		260		402		—		—		—		—		—		—		—		—		—		662
Total Footage (ft)		4,627		18,216		17,178		14,873		15,949		14,146		12,960		17,107		12,436		11,636		1,010		140,139

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Table 13-24: Material to the Mill

Year		0		1		2		3		4		5		6		7		8		9		10		Total
Low-Grade Material
tons (tons x 1,000)		2		31		31		31		35		28		21		23		20		17		2		242
Grade (oz Au/ton)		0.035		0.047		0.047		0.047		0.044		0.048		0.048		0.050		0.053		0.047		0.049		0.047
Ounces (oz Au x 1,000)		0		1		1		1		2		1		1		1		1		1		0		11
Grade (oz Ag/ton)		0.216		0.156		0.178		0.155		0.150		0.171		0.170		0.206		0.186		0.190		0.179		0.171
Ounces (oz Ag x 1000)		0		5		6		5		5		5		4		5		4		3		0		41
High-Grade Material
tons (tons x 1,000)		3		195		256		241		249		237		219		275		213		210		17		2,116
Grade (oz Au/ton)		0.267		0.181		0.209		0.200		0.207		0.211		0.222		0.168		0.152		0.174		0.117		0.191
Ounces (oz Au x 1,000)		1		35		53		48		52		50		49		46		32		37		2		405
Grade (oz Ag/ton)		0.283		0.260		0.286		0.267		0.302		0.291		0.270		0.313		0.301		0.308		0.240		0.289
Ounces (oz Ag x 1000)		1		51		73		64		75		69		59		86		64		65		4		612
Total to Plant
tons (tons x 1,000)		5		226		287		272		284		265		240		298		234		227		19		2,358
Grade (oz Au/ton)		0.167		0.163		0.191		0.182		0.187		0.193		0.207		0.159		0.144		0.165		0.111		0.177
Ounces (oz Au x 1,000)		1		37		55		50		53		51		50		47		34		37		2		417
Grade (oz Ag/ton)		0.254		0.246		0.274		0.254		0.283		0.278		0.261		0.305		0.291		0.299		0.235		0.277
Ounces (oz Ag x 1000)		1		56		79		69		80		74		63		91		68		68		4		653

Table 13-25: Development Schedule

Year		-		1		2		3		4		5		6		7		8		9		10		Total
Development Type
Main Decline (ft)		3,084		2,057		—		—		—		—		—		—		—		—		—		5,141
Level Station (ft)		368		909		—		—		—		—		—		—		—		—		—		1,277
Level Development Waste (ft)		244		1,341		849		181		1,511		917		1,340		733		362		235		—		7,715
Level Development Ore (ft)		298		13,081		16,329		14,692		14,438		13,229		11,620		16,373		12,074		11,401		1,010		124,546
Vent Drift (ft)		374		424		—		—		—		—		—		—		—		—		—		798
Vent Raise (ft)		260		402		—		—		—		—		—		—		—		—		—		662
Total Development (ft)		4,627		18,216		17,178		14,873		15,949		14,146		12,960		17,107		12,436		11,636		1,010		140,139

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Figure 13-36 and Figure 13-37 show the proposed yearly production schedule in terms of tons and gold and silver ounces for the LOM.

Figure 13-36: Proposed Mine Production Schedule (tons by period)

Source: RESPEC, 2026

Figure 13-37: Mine Production Schedule (ounces by period)

Source: RESPEC, 2026

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14 PROCESSING AND RECOVERY METHODS

14.1 Introduction

Based on the information and metallurgical test results summarized in Section 10, the Grassy Mountain gold–silver mineralization is considered amenable to cyanide leaching as a recovery method. The process plant will consist of a 750 tons/day, two-stage crushing, ball mill, carbon-in-leach (CIL), elution, and electrowinning circuit, all of which are well-known, conventional, processing unit operations.

14.2 Process Design Criteria

The process plant is designed for treatment of 750 tons/day or 34 tons/hour based on an availability of 7,998 hours per annum or 91.3%. The crushing section design is set at 70% availability, and the gold room availability is set at 52 weeks per year including two operating days and one smelting day per week. The plant is designed to operate with two 12-h shifts per day, 365 days per year, and will produce doré bars.

Key design parameters derived from metallurgical testwork, as well as the resulting sizing parameters of major equipment, are shown in Table 14-1.

Table 14-1: Process Design Criteria

Description		Units		Value
Plant throughput		tons/year		273,750
Mine life		years		7.8
LOM average grade, Au		oz/ton		0.177
LOM average grade, Ag		oz/ton		0.277
Design grade, Au		oz/ton		0.178
Design grade, Ag (corresponding to design grade for Au)		oz/ton		0.275
Operating Schedule and Stockpile
Crusher availability		%		70
Plant availability (milling and leach)		%		91.3
Crusher operating time		hours/year		6,132
Plant operating time		hours/year		7,998
Gold room operating days		days/year		104
Gold room smelting days		days/year		52
Stockpile type		—		Conical
Stockpile repose angle		°		37
Stockpile retention time		hours		24

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Description		Units		Value
Ore Properties
Specific gravity (average)		—		2.6
JK Axb (25th percentile)		—		30.4
Bond rod work index (BRWi) (75th percentile)		kWh/ton		22.3
Bond ball work index (BBWi) (75th percentile)		kWh/ton		26.9
Bond abrasion index (Ai) (average)		g		0.641
Primary Crushing
Throughput, nominal		tons/hour		45
Primary crusher type				Jaw
Primary crusher model				Metso C80 or equivalent
Closed size setting		inches		2.0
Feed size, F80		inches		8.3
Crushing product, P80		inches		1.9
Secondary Crushing
Circulating load, nominal		%		263
Secondary crusher type				Cone
Secondary crusher model				Metso HP200 or equivalent
Closed size setting		inches		0.6
Feed size, F80		inches		1.6
Milling and Classification
Throughput, nominal		tons/hour		34.2
Ball mill dimensions (diameter x effective grinding length)		Ø x EGL (ft)		12 x 16
Ball mill required power		horsepower		1,021
Ball mill installed power		horsepower		1,341
Ball mill product P80		mesh (µm)		150(106)
Circulating load, max for design		%		350
Cyclone overflow solids		%		45
Carbon-In-Leach
Total leach time required		hours		24
Total leach time available		hours		27
Number of tanks		number		1 pre-aeration + 2 leaching + 7 adsorption
Cyanide addition		lb/ton		0.68
Lime addition		lb/ton		2.1
Carbon concentration		lb/gallon		0.21
Carbon loading (Au + Ag)		oz/ton		214
Carbon consumption		lb/ton		0.06

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Description		Units		Value
Desorption/Electrowinning/Refining
Elution method		—		Pressure Zadra
Carbon batch size		ton		2.2
Elution cycles per week		number		7
Furnace capacity, Au + Ag		lb/smelt		57.5
Cyanide Destruction
Cyanide reduction system		—		SO2 /air
Residence time, max for design		minutes		90
CNWAD in feed, maximum for design		ppm		200
CNWAD discharge, not to exceed		ppm		30
CNWAD discharge target for design		ppm		15
SO2 addition		lb/lb CNWAD		6.4
Hydrated lime addition		lb/lb CNWAD		10.8
Cu addition		lb/lb CNWAD		0.11

14.3 Process Flowsheet Development

The process flowsheet was developed based on information from the metallurgical testwork as outlined in Section 10. The crushing and grinding circuit sizing were determined using Bruno and Ausgrind (Ausenco’s in-house power-based comminution model) simulations, respectively. The flowsheet developed previously was modified to a simpler, lower capital cost alternative comprising:

• two-stage crushing circuit

• grinding circuit

• hybrid leach-CIL circuit with pre-aeration

• mercury removal circuit

• cyanide destruction.

The simplified overall flowsheet is shown in Figure 14-1. The plant site layout is shown in Figure 14-2.

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Figure 14-1:  Simplified Overall Flowsheet

Source: Ausenco, 2020.

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Figure 14-2: Proposed Plant Site Layout

Source: Ausenco, 2020.

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14.4 Overall Process Description

The plant feed will be hauled from the underground mine to a mobile crushing facility that will include a jaw crusher as the primary stage and a cone crusher for secondary size reduction. The crushed ore will be ground by a ball mill in closed circuit with a hydrocyclone cluster. The hydrocyclone overflow with P₈₀ of 150 mesh (106 µm) will flow to a leach-CIL recovery circuit via a pre-aeration tank.

Gold and silver leached in the CIL circuit will be recovered onto activated carbon and eluted in a pressure Zadra-style elution circuit and then precipitated by electrowinning in the gold room. The gold-silver precipitate will be dried in a mercury retort and then mixed with fluxes and smelted in a furnace to pour doré bars. Carbon will be re-activated in a carbon regeneration kiln before being returned to the CIL circuit. Mercury is collected and shipped off site for third party storage.

CIL tailings will be treated for cyanide destruction prior to pumping to the TSF for disposal.

14.4.1 Crushing Circuit

The crushing facility will be a two-stage crushing circuit that will process the run-of-mine (ROM) ore at an average rate of 45 tons/hour. The major equipment and facilities at the ROM receiving and crushing areas will include:

• ore stockpile

• ROM hopper

• vibrating pan feeder

• primary jaw crusher

• coarse ore screen

• secondary crusher surge bin

• secondary crusher vibrating feeder

• secondary cone crusher

• fine ore bin

• feed and product conveyors.

Ore will be trucked from underground and dumped directly into the ROM hopper or onto the outdoor stockpile during crushing circuit downtime. A front-end loader will reclaim ore from the stockpile and move it to the ROM hopper as necessary.

The ROM hopper will continuously feed a vibrating pan feeder which will discharge into the primary jaw crusher. After primary crushing, the ore conveyor will bring the ore to a coarse ore screen. A belt magnet at the end of the ore conveyor will be present to prevent pieces of metal from continuing onto the coarse ore screen.

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Oversize from this screen will be transferred by the secondary crusher feed conveyor to the secondary crusher surge bin. This conveyor will be fitted with a metal detector for the secondary crushing circuit to be temporarily shut down for tramp metal removal. Ore from the secondary crusher surge bin will pass over the second crusher vibrating feeder and into the secondary crusher. After secondary crushing, the ore will recirculate to the coarse ore screen in combination with ore from the primary jaw crusher via the ore conveyor.

Undersize from the coarse ore screen will be taken by the product conveyor to the fine ore bin. The product conveyor will have a weightometer to monitor the crushing circuit throughput.

The fine ore bin discharge feeder will feed ore from the fine ore bin onto the ball mill feed conveyor and over to the grinding circuit and will be fitted with a weightometer to provide data for feed-rate control to the grinding circuit.

14.4.2 Grinding Circuit

The grinding circuit will have an average feed rate of 34.2 tons/hour and will consist of a ball mill and a cyclone cluster in a closed circuit. The recirculating load will have a maximum of 350%. The grinding circuit will be designed for a product size P₈₀ of 150 mesh (106 µm). The major equipment in the primary grinding circuit will include:

• one 12-ft diameter (inside shell) by 16-ft effective grinding length (EGL) single-pinion ball mill driven by a single 1,341 hp fixed-speed drive motor; and

• one cyclone cluster.

As required, steel balls will be added into the ball mill using a ball bucket and ball charging chute to maintain grinding efficiency.

Crushed ore will travel along the ball mill feed conveyor and discharge directly into the ball mill via the mill feed chute. Process water will be added to reach a pulp density of 72% solids (by weight) through the ball mill, which will then discharge to the cyclone feed pump box. Trash or broken mill balls will be discharged to a scats bunker and removed by a front-end loader. Additional process water will be added to the cyclone feed pump box to achieve a density of 63.5% w/w solids, which will then be pumped to the cyclone cluster. The cyclone underflow will recirculate to the mill feed chute. The cyclone overflow will discharge at 45% w/w solids and report to a trash screen. Trash screen oversize will be sent to a trash bin. The slurry will then flow by gravity to the pre-aeration tank.

Maintenance activities in the grinding and classification area will be serviced by a mill area crane, and a grinding area hoist, which will be used for ball mill charging duties and minor lifts. Spillages in the grinding and classification area will be pumped by the grinding area sump pump into the cyclone feed pump box.

14.4.3 Leach/CIL

A pre-aeration tank is included ahead of the leach circuit, as testwork showed this reduced consumption of cyanide and improved recovery. Testwork determined that the optimal leach residence time for gold is 24 hours.

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The adsorption circuit configuration selected was a hybrid leach–CIL circuit (two leach, seven CIL tanks). This circuit configuration is beneficial as it achieves higher loadings of gold on carbon (gold is fast-leaching and approximately 85% of gold is expected to be dissolved before adsorption, resulting in higher loaded carbon grades in the first adsorption tank). This translates into lower soluble losses and a smaller elution circuit size. Selection of identical tank sizes for leach and CIL simplifies tank access and reduces maintenance spares holding. Each tank has a capacity of 42,250 gallons.

The pre-aeration tank will mix the cyclone overflow with low-pressure air. Slurry will overflow the pre-aeration tank to the first leach tank, where lime will be added at a rate of 2.1 lb/ton of feed. Cyanide will be added into both leach tanks at a rate of 0.68 lb/ton of feed, together with low-pressure air.

The slurry will then overflow into seven CIL tanks. The first four CIL tanks will also be fed low-pressure air. Barren carbon will be added to the last CIL tank and will travel up through the circuit in the opposite direction from the slurry flow (counter-current flow). Carbon will advance once per day with carbon transfer pumps, which pump carbon-laden slurry to the next tank in the train. Carbon will be retained in the tanks after the transfer with inter-stage screens, which will have mesh baskets sized to allow slurry to pass through but not the loaded carbon.

Leached tailings will overflow the last tank to the detox tank which in turn will overflow to the carbon safety screen. This screen will collect carbon that would otherwise be lost to the tailings in the event of a hole in one of the inter-stage screens. Loaded carbon will be pumped from the first CIL tank to the elution circuit via a loaded-carbon screen, which will separate the carbon from slurry and send the slurry back to the leach circuit.

14.4.4 Carbon Management

14.4.4.1 Acid Wash

Loaded carbon from the leach circuit will be loaded into an acid-wash column, where it will be submerged in a 3% w/w hydrochloric acid solution in order to dissolve lime scale that would otherwise interfere with the elution and adsorption process. After soaking for 30 minutes, the acid will be drained, and two bed volumes of raw water will be circulated through the column to rinse and neutralize the acid from the carbon. After rinsing, the carbon will be pumped to the elution column via carbon-transfer water.

14.4.4.2 Carbon Elution

A pressure Zadra circuit was selected for elution of gold and silver from carbon due to the small carbon processing requirements of the CIL circuit and unknown water quality from the raw water wells. A pressure Zadra circuit is less complicated than comparable alternatives, and is less sensitive to poor water quality, which makes it a better choice in this instance.

Strip solution (eluate) will be made up in the strip-solution tank using raw water dosed with 2% w/w sodium hydroxide and 0.2% w/w cyanide to form an electrolyte for the electrowinning process. This solution will be circulated through the elution column via an eluate heater, which heats the solution, the carbon, and the column to 275°F. The elution system will be pressurized at a maximum pressure of 65 psi (450 kPa) to keep the solution from flashing to steam in the heater or elution column.

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A recovery heat exchanger will transfer heat from the hot pregnant solution exiting the column to the incoming solution before passing through the solution heater. This will reduce the energy required to maintain the solution temperature and cool the pregnant solution before it enters the electrowinning cell. Once the required system temperature is reached, the hot pregnant eluate solution will be directed to the electrowinning cell, where the metals will be plated onto cathodes. Solution continues to circulate through the elution column and electrowinning cell. The process will continue to deposit metals into the electrowinning cell for a maximum of 16 hours.

14.4.4.3 Carbon Regeneration

At the end of the elution cycle, the barren carbon will be transferred to the regeneration kiln feed hopper where it will be fed into the regeneration kiln. The kiln will regenerate the carbon by burning off any organic material fouling the carbon that would hinder its ability to absorb metals in the CIL circuit. The kiln’s operating temperature will be 1,382°F. The kiln will be fitted with mercury abatement equipment to capture residual mercury on barren carbon.

Regenerated carbon will exit the kiln and report to the water-filled quench tank. The quench tank will serve as a holding place for the carbon while it is waiting to be returned to the circuit. Regenerated carbon will be pumped from the quench tank through a barren carbon screen to remove fines as well as dewater the carbon. Oversize from the screen will then re-enter the CIL circuit via the CIL tank at the end of the bank.

14.4.4.4 Carbon Transport Water

All carbon movements in the elution and regeneration circuits will be accomplished using carbon transport water. A transport-water tank and pump will supply transport water to carbon movement demands as needed. The acid wash and elution columns will be fitted with internal strainers to allow the transport water to drain out while the column retains the carbon.

Transport water will pick up fines when moving carbon due to the attrition associated with carbon movement. The transport water tank will be periodically drained to tailings.

14.4.5 Gold Room

The gold room will house the electrowinning cell, smelting furnace, and associated support equipment within a secured area.

One day per week, the electrowinning cell will be opened so that sludge can be cleaned out manually with a high-pressure water hose. Sludge from the clean-up will flow by gravity to the sludge settling tank and into the gold room sludge filter press to be dewatered. Dewatered sludge will then be transported manually using a tray to the mercury retort oven for mercury removal as well as simultaneous drying. Mercury collected will be sent off site for third-party processing.

Dried sludge will be removed from the oven the following day and combined with fluxes in a flux mixer before reporting to the smelt furnace. Once all the mixture has been added to the furnace and enough time has elapsed for the material to fully melt, the slag will be poured into a conical slag pot. The liquid metal will then be poured into molds on a mound tray. Cooled doré will then be cleaned, weighed, and stamped. The bars will be placed in a vault to await shipment to a refinery.

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Dust collection will be provided in the gold room for smelting. Extraction fans are planned for the kiln, electrowinning cell, retort/drying oven, and smelting-furnace off gasses. All extraction fans will lead to a gas scrubbing system.

14.4.6 Cyanide Detoxification and Tailings Deposition

A cyanide-destruction circuit will be included in the design to comply with tailings-discharge permit requirements. Testwork shows that SO₂/air process was an effective detoxification method at reducing weak-acid dissociable (WAD) cyanide levels to 15 mg/L (30 mg/L maximum).

The CIL tailings will be pumped to the cyanide detoxification tank, where lime will be added to buffer pH, copper sulfate will be added as a reaction catalyst, and sodium metabisulfite (SMBS) will be added as an SO₂ source. The tank is sized to provide 90 minutes of residence time for the reaction to reach completion.

Detoxified slurry will overflow to the tailings pump box where it will be pumped to the TSF by the final tailings pumps. At the TSF, the tailings will be deposited using spigot manifolds positioned along the rim of the impoundment to create low-angle deposition beaches. The position of the spigot manifolds will be moved periodically to produce an even beach head and push decant water towards the decant water pool. A pontoon-mounted decant-return water pump will be provided to pump decant water back to the process water tank for re-use in the plant.

14.4.7 Reagent Handling and Storage

Reagents will be prepared and stored in separate self-contained areas within the process plant and delivered by individual metering pumps or centrifugal pumps to the required addition points. Acidic and basic reagents will be stored and mixed in physically separated areas to ensure no exposure of cyanide to acidic chemicals, which would generate hydrogen-cyanide gas.

Estimated reagent consumptions are as follows:

• Lime: 6.3 lb/ton of ore processed

• Sodium cyanide: 0.91 lb/ton of ore processed

• Sodium metabisulfite: 3.6 lb/ton of cyanide processed.

14.4.7.1 Hydrated Lime

Preparation of hydrated lime slurry will require:

• a bulk storage silo

• a mixing tank

• dosing pumps feeding a ring main

• automatically controlled dosing point from the ring main.

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Hydrated lime will be used in leaching and detoxification for pH control. Hydrated lime powder will be delivered to site by bulk tankers and blown into the lime bulk storage silo. When the mixing-tank is low, hydrated lime will be added to the tank via a rotary valve and screw feeder. Process water will be added at the same time to maintain the mixture strength of 20% w/w, forming a suspended lime slurry.

The suspended lime slurry will be distributed to the various dosage points via a ring main that provides constant flow to various destinations. Dosing will be accomplished with drop lines off the ring main with automated on-off valves that open when pH is low and close when the target pH is reached.

14.4.7.2 Sodium Cyanide

Storage and distribution of sodium cyanide (NaCN) will require:

• a bulk storage tank

• a ring main

• dosing pumps.

NaCN will be used in the leach circuit as a lixiviant and in elution as a carbon-stripping aid. Aqueous sodium cyanide will be delivered to site by bulk tanker at 30% purity and emptied into the sodium cyanide storage tank. NaCN solution will be distributed to the various dosage points via a ring main that provides constant flow to various destinations.

14.4.7.3 Sodium Hydroxide

Preparation of sodium hydroxide (NaOH) will require dosing pumps. NaOH will be delivered to site in 264.2-gal totes at a solution strength of around 50% w/w. New totes will be lifted onto a mount using a forklift. Dosing will be done at full strength using dedicated positive-displacement metering pumps. NaOH will be used as an electrolyte in carbon elution/electrowinning.

14.4.7.4 Sodium Metabisulfite

Preparation of SMBS will require:

• a bulk handling system

• mixing and holding tanks

• dosing pumps.

SMBS will be a source of SO₂ for cyanide destruction with the SO₂/air process. It will be delivered to site in 1.1-ton bulk bags.

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SMBS will be held in the SMBS storage tank after it is mixed. When the storage-tank is low, a SMBS mixture will be started by dropping a bulk bag of SMBS onto a bag breaker, which discharges SMBS into the mix tank. The mix tank will have been previously filled with the required amount of process water to produce a mixture strength of 20% w/w. Once mixing is complete, the SMBS will be dosed from the storage tank to the cyanide detoxification circuit. There will be two positive displacement metering pumps dedicated to this process, one of which will be in place as a spare.

14.4.7.5 Copper Sulfate

Distribution of copper sulfate (CuSO₄) will require dosing pumps. CuSO₄ will be delivered to site in 53-gal drums at a solution strength of 15% w/w. New drums will be listed onto a mount using a forklift. Dosing to the detoxification circuit will be done using dedicated positive-displacement metering pumps.

14.4.7.6 Hydrochloric Acid

Distribution of hydrochloric acid (HCl) will require a dosing pump. HCl will be used to remove lime scale from loaded carbon in the acid-wash column of the elution circuit. HCl will be delivered in 264.2-gallon totes at 32% w/w solution strength and will be housed in the reagent handling area.

Raw water will be added to the HCl to a strength of 3% w/w by inline mixing ahead of the acid-wash column.

14.4.8 Air Supply and Distribution

14.4.8.1 Low-Pressure Air

Two low-pressure air blowers will supply air to the pre-aeration, leach, and detoxification circuits. The installed blowers will be multiple-stage, centrifugal-type blowers and will be used with a “blow-off” arrangement to adapt to fluctuations in air demand.

14.4.8.2 Plant and Instrument Air

Two plant-air compressors (duty/standby) will provide high-pressure compressed air, to meet the demand for plant and instrument-air requirements. Wet plant air will be stored in the plant-air receivers to account for variation in demand prior to being distributed through the plant. Wet air will report to cyanide offloading. Instrument air will be filtered then dried in the instrument-air dryer before reporting to the gold room or general plant distribution.

14.4.9 Water Supply and Distribution

14.4.9.1 Raw Water

Raw water will be pumped from borehole wells via a well water pump to the raw-water storage tank. Raw water in the raw-water storage tank will be used to supply the process water tank, gland water, reagent mixing, and fire-protection requirements. The raw water tank is sized to include a fire water reserve.

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14.4.9.2 Potable Water

Potable water will be sourced from the raw water tank and treated in the potable water treatment plant. Treated water will then be stored in the potable-water storage tank for distribution by two potable-water pumps in a duty/standby configuration.

14.4.9.3 Gland Water

Gland water will be supplied from the raw-water tank and distributed to the plant by two gland-seal water pumps in a duty/standby configuration.

14.4.9.4 Process Water

Process water primarily consist of TSF reclaim water. Process water will be stored in the process water storage tank and distributed by two process water pumps, in a duty/standby configuration.

14.5 Personnel

The number of process operations and maintenance personnel is provided in Section 18.2.3.5.

14.6 Sampling and Metallurgical Laboratory

The process plant will be equipped with automatic samplers to collect shift and routine samples for aqua-regia digestion, AA analysis, and fire assays. Samples to be taken will include head, intermediate products, tailings, and doré. The data obtained will be used for product quality control, metal accounting and process optimization.

The metallurgical laboratory will perform metallurgical tests for quality control and optimization of the process flowsheet. The laboratory will include equipment such as laboratory crushers, ball mill, sieve screens, bottle rollers, leach reactors, balances, DO meters, and pH meters.

14.7 Projected Energy Requirements

The installed power for the process plant will be 4,445 hp and the power consumption is estimated to be 72 kWh/ton processed.

14.8 Project Water Requirements

The overall projected plant water balance is shown in Figure 14-3. Raw water demand is projected to be 47,023 gallons per day (178 m³/day).

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Figure 14-3: Projected Daily Plant Water Balance , at average LOM throughput

Source: Ausenco, 2026.

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15 INFRASTRUCTURE

15.1 Introduction

Infrastructure contemplated in the FS includes:

• Underground mine, including portal and decline

• Roads: main access road, site access road, borrow pit haul road, tailings storage facility haul road, temporary waste rock storage facility haul road, explosives light vehicle access road and ventilation raise and laydown light vehicle access road

• Site main gate and guard house

• Administration building, training, first aid, change house and car park

• Control room

• Reagent storage area

• Gold room

• Assay laboratory and sample preparation area

• Plant workshop and warehouse

• Truck shop, warehouse, wash pad

• Fuel facility, fuel storage and dispensing

• Water wells

• 14.4 kV overland power line

• Fresh water supply and treatment

• Raw water tank

• TSF

• Temporary Waste Rock Storage Facility (TWRSF)

• Explosives magazine.

A layout of the proposed major infrastructure is included in Figure 15-1.

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Figure 15-1:  Proposed Infrastructure Layout Plan

Source: Ausenco, 2020

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15.2 Access

Access to the Project area is described in Section 4. The FS envisages that the main access road to Grassy Mountain will use an existing BLM road to the site. This road is approximately 17 miles long and will be upgraded to include some straightening and widening in portions.

15.3 Temporary Waste Rock Storage Facility (TWRSF)

The following summarizes the results and interpretations for the TWRSF based on data collected and engineering means and methods presented in the 2021 Detailed Design Report (Golder, 2021d).

Waste rock materials generated during mining will be stockpiled in a TWRSF near the TSF for use as either cement rock backfill to support the underground mining operation or as an operational layer above the tailings surface for closure as discussed in Section 15.5.6. As required by the Oregon Administrative Rule, the potential sulfides in the waste rock material requires the TWRSF to be a geomembrane-lined facility. The containment and drainage collection systems installed below the TWRSF will be the same systems used for the TSF impoundment basin described in Section 15.5.

Above the geomembrane liner, a collection system consisting of perforated piping will be installed within the drainage layer to collect water coming in contact with the waste rock. Captured precipitation infiltrating through the waste rock will be conveyed to the TSF reclaim pond for monitoring and management. The TWRSF collection pipe will remain isolated from the TSF underdrain collection system so the water can be handled separately, if necessary.

The location of the TWRSF, adjacent to the TSF, will allow the lining system to tie into the TSF lining system to provide continuous containment (see Figure 15-2). The TWRSF collection pipe will gravity drain through the TSF impoundment where it will be installed within the TSF drainage layer and ultimately outlet at the TSF Reclaim Pond for independent monitoring and management.

During reclamation, remaining waste rock (if any) stockpiled on the TWRSF will be removed and placed as an operation layer above the tailings surface as part of the TSF reclamation strategy. The TWRSF lining system will either be removed or buried upon completion of mining operations. Further discussion of the TWRSF closure strategy is discussed in Section 17.8.

15.4 Basalt Borrow Quarry

The Basalt Borrow Quarry will be located on the east side of the mine area (refer to Figure 15-2) where there are basalts that are believed to be suitable for construction, mine-backfill and reclamation materials:

• Construction.

• Run-of-mine (ROM) material for fill and TSF-embankment construction, as required.

• Screened and processed materials for drainage and filter materials in the TSF and TWRSF, as required; Backfill: backfill and CRF material for backfilling of underground stopes; crushed to -6 inches.

• Reclamation: screened and processed materials for drainage and filter materials, as required.

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Borrow material from the Basalt Borrow Quarry will be mined using contract mining. During initial construction, where more material is needed, the borrow mining will use larger equipment, while smaller equipment will be used during production when the amount of material required is reduced. A small contractor laydown-yard is planned near the main borrow source area.

15.5 Tailings Storage Facility

The following summarizes the results and interpretations for the tailings storage facility based on data collected and engineering means and methods presented in the 2021 Tailings Storage Facility and Temporary Waste Rock Storage Facility detailed design report (Golder, 2021d).

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The TSF will be constructed in three primary stages to store a total of 3.64 Mt of tailings and industry-accepted design criteria for geotechnical stability and flood events during operations and long-term closure (passive care). The combined tailings dam embankment and impoundment basin will occupy an ultimate footprint of approximately 108 acres (4.705 million sqft), as shown on Figure 15-2. The TSF centroid is located is located in mine grid at 15,865,300 N and 1,543,500 E approximately 0.3 mi west and 0.1 mi north of the overall mine site centroid.

Figure 15-2:  Overall TSF Layout

Source: Golder, 2021d.

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Conventional tailings are transported to the TSF via a tailings delivery pipeline from the mill. Tailings are then deposited into the TSF impoundment from the staged perimeter road via sub-aerial deposition. As tailings are deposited, free water separates from the slurry mix to form the supernatant pool. Through consolidation and seepage, additional water reports to the impoundment underdrain system where it drains via gravity into the reclaim pond system. Water recovery from the TSF will include independent pumping and piping systems from the supernatant pool to and reclaim pond which will combine into a single return water system for reuse at the mill.

Non-contact stormwater is managed through a series of permanent and temporary stormwater diversion channels constructed upgradient of the TSF. Precipitation falling on the TSF and areas downgradient of the stormwater channels ultimately reports to the supernatant pool where it is incorporated into the process circuit.

Additional details regarding design criteria, methodology, and engineering evaluations of the TSF are presented in the following sections.

15.5.1 Topography, Drainage, and Vegetation

In general, the mine site and surrounding area has rolling topography with bedrock exposed at or near the ground surface in upland and hill areas, including Grassy Mountain proper. Within the TSF area, as topographic elevation drops, the surrounding hills transition into broad valleys with shallow alluvial soils overlying deeper lacustrine clays.

The TSF area generally slopes from south to north at about two percent along the valley floor. Valley wall slopes to the east and west ranging from about 10% to 15%, and about 5% in the south along the higher valley slopes in the southern portion of the TSF basin.

Vegetation across the site generally consisted of moderately dense native shrubs and grasses. No surface water, perennial streams, or springs were observed within the TSF footprint or TWRSF areas at the time of the geotechnical field investigations.

15.5.2 Past Studies, Subsurface Investigations, and Civil Design

Several previous studies and investigations have been completed to support various scoping studies and designs of the TSF. Golder Associates USA Inc. (Golder) utilized information obtained from the following prior studies for this TSF design in conjunction with the FS Project design criteria defined by Paramount and Ausenco:

• Siting Study Letter Report titled Grassy Mountain Project – Tailings Storage Facility Siting and Trade-off Study. December 2016 (Golder 2016b). Updated for Consolidated Permit Application in September 2019 (Golder 2019b).

• Design Report titled Pre-feasibility Design, Tailings Storage Facility for Calico included a geotechnical subsurface investigation at the proposed TSF site in December 2017 consisting of 15 geotechnical borings and excavating 44 test pits in the project area (Golder 2018b).

• Design Report titled Detailed Design, Tailings Storage Facility and Waste Rock Dump for Calico (Golder 2019c) included:

• March 2019 – six geotechnical boreholes within the TSF area and laboratory testing;

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• April 2019 – geotechnical tailings testing program; and

• July 2019 – 11 cone penetration test soundings within TSF area.

• Design Report titled Detailed Design, Tailings Storage Facility and Temporary Waste Rock Storage Facility for Calico (Golder 2021d) included a geotechnical subsurface investigation included 16 test pits at the proposed closure cover borrow areas and 2 test pits within the TWRSF footprint.

15.5.3  Design Objectives

The TSF design was developed by Golder using designs and methods that protect against impacts to groundwater in accordance with State and Federal environmental and dam safety guidelines and regulations. The dam design as presented exceeds the dam safety requirements of OAR 625 Division 20 – Dam Safety for a Low Hazard dam.

In July 2020, the Oregon Water Resources Department (OWRD) issued approval for the TSF based on the November 2019 Revision 0 design confirming the Low Hazard designation (OWRD 2020). In July 2025, WSP submitted a permit extension request to the OWRD provide approval continuation to the dam safety permit for an additional five years (WSP 2025). OWRD provided email approval extension in July 2025 (OWRD 2025).

15.5.3.1  Basis of Design

The TSF consists of an earth- and rock-fill dam spanning a shallow valley at the north limits of the TSF site to impound tailings to the south. A saddle dam constructed along the western ridge will be required beginning in Stage 2. The dam will be developed using concepts that will provide a safe and stable dam during all stages of construction, operation, and closure. The impoundment basin will be lined with multi-layered composite containment system consisting of an enhanced geosynthetic clay liner (GCL), leak detection, and high-density polyethylene (HDPE) geomembrane liner to contain the tailings solids and fluids. The lining system will extend to the upstream crest of the embankment. Tailings will be transferred to the TSF with an average solids concentration of 42.4%, by weight through a slurry pipeline from the mill.

15.5.3.2  Mill Throughput

Upon completion of plant commissioning, tailings are anticipated to be delivered to the TSF via a slurry pipeline. Total mill throughput for LOM is approximately 2.4 Mtons.

15.5.3.3  Tailings Density and Storage Capacity

Geotechnical testing and consolidation modelling performed by Golder estimates a tailings settled dry density of 80 lb/ft³. Based on the TSF design, the Stage 3 TSF will provide a total storage capacity of 3.64 Mtons. However, for the LOM, only 2.4 Mtons are planned to be delivered to the TSF, and, therefore, only Stages 1A, 1B, 2, and a portion of Stage 3 will be required for this Study’s LOM plan. The design capacity considerations for each stage are outlined in Table 15-1.

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Table 15-1:  Stage Capacity Relationship

Stage		Elevation (ft)				Maximum Tailings Surface Area (acres)		Storage Capacity (M tons)
		Main Embankment Crest		Maximum Tailings Surface				Stage		Cumulative
1A		Varies (Min. 3583)		3581		42.0		0.40		0.40
1B		Varies (Min. 3595)		3593		44.7		0.58		0.98
2		Varies (Min. 3609)		3607		59.5		1.06		2.04
3		Varies (Min. 3622)		3620		83.0		1.60		3.64*

* Additional storage capacity is available with the Stage 3 expansion. During operation, construction of Stage 3 may be optimized for the LOM requirement, resulting in a lower Stage 3 capital construction cost.

15.5.4  TSF Design

15.5.4.1  Embankment Construction

The embankments will be constructed in three primary stages. Stage 1 will be separated into two intermediate stages (Stage 1A and 1B). Stage 2 and Stage 3 will be constructed as downstream raises along the north and west embankments. The embankments will be constructed of soil and/or rock materials using downstream construction methods. Suitable embankment materials will be generated from the on-site basalt borrow area and during impoundment grading operations.

The embankments will have a maximum overall upstream slope of 3H:1V, with a downstream slope of 2.5H:1V. The overall embankment slopes are suitable for long-term geotechnical stability, closure, and meeting Oregon Administrative Rules requirements. The north and west embankments will have a maximum height of 84 feet and 30 feet, respectively. The crest width of the north embankment will be 50 ft, and the smaller west embankment will have a 30-ft wide crest. The TSF is designed as a “zero discharge” facility to meet OAR requirements. To achieve this, the facility will be a 100% geomembrane-lined facility with a continuous, engineered lining system extending across the impoundment basin and the upstream slope of the embankments.

Downstream construction will be accomplished by extending new embankment against the existing downstream slope of the previous stage and then raising the embankment up to the new crest elevation for each stage as shown in Figure 15-3.

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Figure 15-3:  TSF Main (North) Embankment Cross-section

Source: Golder, 2021d.

15.5.4.2  Containment and Underdrain System

To achieve “zero discharge” and provide environmental containment as required by OAR, the composite lining system within the impoundment basin will consist of (from bottom to top) a six-inch to 12-inch thick prepared subgrade, a 300-mil thick enhanced geosynthetic clay liner, 80-mil HDPE geomembrane liner, an 18-inch thick drainage layer, and a six-inch thick filter layer. An underdrain collection system consisting of perforated piping will be located within the drainage layer to promote drainage of the tailings. The upstream slope of the embankments will use the same composite lining system, but without the overlying piping, drainage and filter layers.

15.5.4.3  Tailings Deposition Management and Return Water

A reclaim pond, located downstream (north) of the TSF, will capture all tailings draindown collected in the underdrain collection system from the tailings. To achieve “zero discharge” and provide environmental containment as required by the Oregon Administrative Rules, the lining system for the reclaim pond will consist of (from bottom to top): a prepared-in-place subgrade, 60-mil HDPE secondary geomembrane liner, HDPE geonet, and 80-mil HDPE geomembrane primary liner. The geonet located between the two geomembranes will serve as the leakage collection and recovery system.

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The supernatant pool will be maintained away from the embankments on the eastern side of the facility by controlled deposition of tailings from spigots installed around the perimeter of the facility. Water separating from the tailings solids after deposition will be managed with two independent return-water systems. One will manage flows collected in the reclaim pond from the underdrain collection systems and the other will manage water collected in the supernatant pool. The supernatant pool will be managed with a pump installed either on the eastern edge of the facility or on a floating barge within the pool. Water from both systems will be returned to the mill for use in the process circuit. At all times, process fluid pipelines will be located above secondary containment that consists of either geomembrane liners or reinforced concrete containment structures.

Precipitation falling on area downgradient of the diversion channels and above geomembrane-lined areas will is captured and incorporated into the process circuit. Seasonal fluctuations in precipitation and evaporation are accounted for in the process fluid water balance prepared by Golder.

15.5.4.4 Surface Water Management

The TSF will be capable of storing runoff from tributary areas and direct precipitation on the facility resulting from a 500-year, 24-hour storm event, as well as an allowance for wave run-up due to wind action. Permanent and temporary stormwater diversions will collect and divert a majority of the stormwater runoff around the facility to a natural drainage on the north side of the TSF.

15.5.4.5 Geotechnical Stability

The embankments are designed by Golder to be geotechnically stable during normal operation, and during the design seismic event. For this design, Golder performed a site-specific seismic and faulting hazard assessment to estimate peak ground motions resulting from various seismic events. The maximum credible earthquake (MCE) was selected as the design seismic event for long-term closure. This selected design seismic event is suitable for any hazard classification determined by regulatory agencies.

15.5.5 Monitoring

The TSF design was advanced to construction-level to support on-going State and Federal permitting. To support construction-level design and permitting, Golder prepared a detailed geotechnical monitoring plan that defines the roles and responsibilities of key stakeholders (Owner, operator, engineer) for safe and stable TSF construction and operation. Monitoring will be accomplished through both measurements of the monitoring points and visual observations of surface conditions.

The geotechnical monitoring plan (Golder 2021d) provides definition on normal and abnormal operating conditions. A network of monitoring instruments will be installed during each stage of construction to monitor critical geotechnical conditions as they relate to dam stability and environmental containment. Trigger actions response plans have also been developed by Golder to guide key stakeholders in their response to specific conditions.

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15.5.6 Closure

When mining operations are complete, active tailings deposition from the mill into the TSF will cease. Water collected in the reclaim pond will be recirculated to the supernatant pool for active water management. Over time, the supernatant pool will evaporate and the underdrain flows reporting from the TSF will reduce as the tailings consolidate and drain.

Under the conceptual closure plan, once the tailings surface no longer has a free water surface and the tailings continue to desiccate and densify, a closure cover will be constructed over the tailings surface and TSF embankments. The conceptual closure plan recommends that installation of the closure cover is at a point in time where majority of the tailings consolidation has occurred and is not expected to negatively impact drainage of the closure cover.

The closure cover above the tailings surface will be constructed with the following (bottom to top):

• Operational layer of waste rock (if available) or other materials to provide vehicle access (as needed).

• 4 to 12 inches of Liner bedding (if required).

• 60-mil double sided textured linear low-density polyethylene (LLDPE) geomembrane liner.

• 12 inches of non-acid generating granular drainage layer.

• 12 ounce per square yard (oz/sy) non-woven geotextile.

• 12 inches of growth medium, scarified and revegetated.

The TSF embankment closure cover will consist of 12 inches of growth medium placed on the crest and downstream slopes of the TSF embankments. After placement, the growth medium will be scarified and revegetated.

Closure cover material will be sourced from the Closure Cover Borrow Areas located northwest of the basalt quarry and southwest of the TSF.

The remaining waste rock (if any) stockpiled on the TWRSF will be removed and placed as an operation layer above the tailings surface when it is safe to do so. The TWRSF lining system will either be removed or buried upon completion of mining operations. Stormwater falling on the TSF and upgradient catchment areas, below the permanent diversion channels, will be routed over the covered impoundment surface to a closure drop chute channel located at the eastern abutment of the north embankment. The closure drop chute and impoundment surface swale are designed to safely convey stormwater flows resulting from a 500-year, 24-hour storm event.

Once tailings draindown flow rates reduce to levels suitable for passive water management (depending on the long-term passive management system), the reclaim pond will be retrofitted to a geomembrane-lined evaporation pond. With installation of the closure cover and gravity drainage from the underdrain collection system, it is expected that draindown from the TSF will cease. Once drainage from the TSF has ceased, the evaporation pond will be removed.

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15.6 Closure Cover Borrow Areas

To support final reclamation, closure cover will be sourced from growth media stockpiles generated during construction as well as designated closure cover borrow areas as presented on Figure 15-2. During initial mine development, and staged construction of the TSF, growth media and topsoil will be stripped and stockpiled in designated locations north of the TSF and immediately west of the Basalt Borrow Quarry. During reclamation, the growth media stockpiles will be excavated and placed as vegetative closure cover. Once depleted, the Closure Cover Borrow Areas located immediately west of the Basalt Borrow Quarry and south of the TSF will be developed as additional vegetative closure cover material.

Growth media stockpiles will be constructed with maximum 2.5H:1V side slopes and re-vegetated. The Closure Cover Borrow Areas will be excavated as needed with maximum 2.5H:1V side slopes and the floor of the quarry will be graded to drain to natural drainages. Upon completion of reclamation activities, the final Closure Cover Borrow Area quarries will be re-vegetated.

15.7 Water Management

15.7.1 Non-Contact Water Management

The following summarizes the results and interpretations for the stormwater diversion channels based on data collected and engineering means and methods presented in the 2019 Hydrology Analysis and Stormwater Diversion Recommendations for the Process and Portal Pads (Golder, 2019a), 2021 Tailings Storage Facility and Temporary Waste Rock Storage Facility detailed design report (Golder, 2021d) and 2021 stormwater pollution control plan (Golder, 2021a).

The Project site is located approximately 6.5 miles northwest of Lake Owyhee in the semi-arid plateau of eastern Oregon and local landscape is typical of high mountain desert environment and rangeland. The terrain is gentle to moderate with relatively low relief. Elevation ranges from approximately 4,050 feet above mean sea level at the southeastern corner of the proposed borrow pit area to 3,330 feet above mean sea level north of the TSF reclaim pond. Drainage at the site is generally to the north in ephemeral natural drainages. No perennial streams or wetlands exist at the site.

The Project site is divided into three main hydrologic catchment areas. Each catchment area was used to size temporary and permanent diversion channels that route water around the zero-discharge process areas. The catchment areas are shown on Table 15-3 and defined as:

• TSF area: All western hydrologic catchment areas draining to the TSF area; 688 acres.

• Process pad and portal pad area: All interior hydrologic catchment areas draining to the processing area and portal; 12.4 acres.

• Site wide area: All eastern hydrologic catchment areas draining to the planned borrow pit area and the catchment for the existing natural drainage immediately west of the borrow pit; 664 acres.

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The overall Project site catchment area has a total tributary area covering approximately 1,350 acres. Hydrologic catchments areas were developed based on existing topographic features and identifying areas where calculated peak flows will be required for hydraulic design of drainage improvements.

Figure 15-4:  Site-wide Hydrologic Catchment Areas

Source: Golder, 2021a.

Hydrologic and hydraulic analyses were completed with weighted average soil characteristic curve numbers and time of concentrations. This model developed flows from each sub-basin for the 25- year, 24-hour; 100-year, 24-hour; and the 500-year, 24-hour storm events. The flows were used to design the surface water diversion and contact water collection channels, culverts, and outlet aprons.

The following design storm events and freeboard capacity were applied:

• Permanent channels: 100-year, 24-hour storm event with freeboard (9 inches), or 500-year, 24-hour storm event without overtopping.

• Temporary channels: 25-year, 24-hour storm event with freeboard (9 inches), or 100-year, 24-hour storm event without overtopping.

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All culverts were designed to only be in place during operation and were therefore designed to convey the 25-year, 24-hour storm event. Channel velocities were reviewed by Golder during hydraulic design of the stormwater diversion channels to determine appropriate channel lining systems for erosion protection. In most areas, unless in permanent diversion channels, the channels will be either unlined or riprap-lined with variable stone sizes.

In areas where channel velocities exceeded the reliability limits of a natural soil lining, riprap lining systems will be used. Dissipation aprons will be located at permanent channel discharge points around the TSF where run-off will be discharged into existing natural drainages to encourage a smooth transition into the existing drainage and minimize erosion to the natural slopes.

Non-contact water runoff is designed to flow into natural drainages downstream of the site to unnamed tributaries of Negro Rock Canyon that in turn discharges to the lower Malheur River.

15.7.2 Contact Water Management

Meteoric water contacting impacted materials at the TSF and TWRSF will be managed within the TSF process fluid water balance a discussed in Section 15.5.4.1. Meteoric water contacting process plant and associated infrastructure will be diverted through a network of contact water diversion ditches and channels to a geomembrane-lined contact water pond to be located east of the process plant.

The process plant contact water pond will be a geomembrane-lined containment pond using a dual containment and leakage collection system.

Figure 15-4 shows the proposed locations of the structures to control contact and non-contact surface water routing around the process plant site. The process plant contact water pond, designed by Ausenco, will be a geomembrane-lined containment pond using a dual containment and leakage collection system. The containment system consists of (from bottom to top):

• prepared subgrade

• 12 inches of soil liner bedding

• 60-mil HDPE geomembrane liner

• Geonet

• 80-mil HDPE geomembrane liner.

Water entering the process plant containment pond will be used in the process circuit or evaporated.

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Figure 15-5: Process Plant Stormwater Contact and Non-contact Catchment Areas

Source: Golder, 2019a.

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15.7.3 Site-wide Water Balance

A high-level site-wide water balance was developed based on the following assumptions:

• Annual average water demands from the process plant mass balance (estimated by Ausenco).

• Usage of water extracted from dewatering operations in the process circuit and to supply the underground mining equipment (estimated by Lorax):

• Low dewatering estimate = 12 gpm

• Mid-range dewatering estimate = 23 gpm

• High dewatering estimate = 78 gpm.

• Water for underground equipment, of about 76 gpm (estimated by MDA) will be sourced from underground dewatering and raw water production and recirculated as needed.

• Tailings slurry concentration of 42.4% solids, by weight, during deposition (estimated by Ausenco).

• Climate conditions based on TSF water balance (estimated by Golder, 2021d).

• Water collected in the process plant contact water pond will be used in the process circuit or evaporated.

• Additional raw water will be supplied by the proposed production wells as make-up water.

Water demands will vary seasonally (Table 15-2).

Table 15-2: Annual Average Water Balance

		Item		M gallons/year
Demand		Total water for tailings discharge			92.8
Demand total					92.8
Source/supply		Raw water for elution circuit			17.2
		Ore feed			3.6
		Underground dewatering			12.1
		TSF return water			47.5
		Plant contact water pond			0.4
Source/supply total					80.7
Make-up water					12.1

Note: Table based on average annual climate and mid-range dewatering estimate.

Water supply from the raw water production wells and mine dewatering is projected to be sufficient to support the FS mine plan requirements and during seasonal fluctuations. Water demands are expected to increase and decrease seasonally and during periods of extended dry and wet climactic years, respectively. During periods of extended dry conditions, additional make-up water from the production wells may be required. During extended periods of wet conditions, raw water from the production wells will be reduced as needed. Additionally, if operated within the design parameters, the TSF supernatant pool may be used to provide seasonal buffer for water demands. On an as needed basis, enhanced evaporation through the use of spray evaporators over the tailings surface during the dry season can be implemented.

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15.8 Built Infrastructure

The built infrastructure requirements are summarized in Table 15-3.

Table 15-3: Built Infrastructure Requirements

Item		Comment
Process plant		Steel-frame and metal clad building with an area of 7,000 ft2. Will include a bridge crane that comes with an electric chain hoist and trolley and control pendant
Process plant control room		Single-level modular steel container, modular building, preassembled. Will include insulated steel doors, windows, operator’s desk, soundproof and dustproof with an area of 135 ft2.
Gold room		Pre-cast masonry building of approximately 1,000 ft2. Will include an electric chain hoist and trolley
Assay laboratory		Single-level steel containers of approximately 2,715 ft2 to be situated adjacent to the process building. Will include sample receiving and preparation, fire assay, weighing room, wet analytical laboratory, dry instrument room, and utilities and storage modules. Will house the laboratory equipment for assaying, metallurgical, and environmental requirements. Dust-collection equipment will be located external to the laboratory building. The building will be serviced with power, water, air conditioning and heating, communications, air and mercury scrubbers, and fume hoods.
Process plant workshop and warehouse		Pre-engineered steel-frame and metal clad building of approximately 2,540 ft2. Will be used to perform maintenance for process equipment, as well as for the storage of equipment spare parts
Administration building		Single level modular wood frame, 80 x 110 ft for a total footprint of approximately 8,800 ft2. Will house the site management team, including general management, commercial and administration management, engineering, mine operations, senior processing, and maintenance personnel. Will be serviced with power, water, air conditioning and heating, communications.
Contractor office and laydown		Modular trailer with an area of 160 ft2
Truck workshop and warehouse		Pre-engineered steel-frame and metal-clad building with an area of 6,250 ft2. Will be positioned adjacent to the mine-office building. Will be divided into two sections, one for warehousing spare parts and tool storage and the other for a maintenance workshop. A bridge crane will be included
Vehicle wash-bay		Open-air, 50 x 50-ft concrete slab with a fluid-collection sump and oil-water separator that will be located adjacent to the truck workshop and warehouse. Wash water will be collected in the sump where settling will occur prior to the water being recirculated back to the wash system. The oil-water separation system will recover hydrocarbons prior to re-use of the wash water. The recovered hydrocarbons will be collected and shipped offsite for disposal in accordance with applicable environmental regulations.
Security gate house		Pre-assembled wood-frame modular building with an area of 325 ft2. The building will include lift gates and one turnstile. 22,350 ft of security fencing will be installed around the entire mine site, including the borrow source area. There will be a main gate where the main access road enters the site, and a second gate will be placed at the southern end of the property. The southern access gate is anticipated to remain locked with access only allowed as needed.

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Item		Comment
Explosives-storage facilities		Will be constructed at the southwest side of the mine area. This location uses a hill as a natural barrier between the explosives-storage facility and other infrastructure. Will consist of a powder magazine in accordance with current applicable explosives regulations. Dirt berms will be placed around the magazines for additional security. Explosives will be delivered to site by vendors using the main access.
Fuel		Two double-walled steel tanks will be used for diesel storage. The total volume between the two tanks is 8,250 gal. Will be used by the underground equipment. A fuel truck will be used to fuel underground equipment as required and may be used to fuel surface equipment as needed.
Air		High-pressure compressed air will be provided by one duty screw compressor, one standby screw compressor, and a duty-plant air receiver. Two high-pressure air uses: instrument air and plant air. Instrument air will be dried and then stored in a dedicated air receiver. Plant air will be fed straight from the plant air receiver without a drying step. Low-pressure air for pre-aeration tank air requirements will be provided by two duty and one standby rotary air compressor.
Communications		On-site communications will comprise inter-connected mobile and fixed systems, including a land-line telephone network, portable two-way radios, and internet. Access for internet and corporate network connection will be made via satellite connections. Underground communication with the surface will be via a leaky-feeder system

15.9 Camps and Accommodation

No accommodations camps are envisaged. Personnel are expected to reside in nearby communities such as Vale, OR, and Boise, ID.

15.10 Power and Electrical

The power supply will initially be from diesel power generators located on site. The diesel power generators will be used for approximately one year during initial construction and the initial mining of the decline. During the construction period a new power line would be constructed along the main access road to site. Once construction of the primary power lines is completed, the generators will remain on site for backup in case of power outages.

The construction of line power will deliver approximately 5.3 MW of power to site and will require a 23-mi distribution circuit, a new 69/34.5 kV to 14 MV transformer, and a new 34.5kV 67-amp regulator. The power line would be constructed from the Hope Substation near Vale to the mine site along the main access road.

The plant power distribution from the powerhouse will be via overhead powerlines. The distribution voltage to the local electrical rooms will be 14.4 kV. There will be a combination control room and motor-control-center room. This room will be pre-fabricated and loaded with electrical equipment prior to delivery to site. The power distribution from the electrical rooms will be 480 V.

The total connected load for the process plant is expected to be 4.8 MW, with an average power draw of 3.6 MW. Power requirements for the underground mine are discussed in Section 13.12.3.

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16 MARKET STUDIES

16.1 Introduction

The proposed Grassy Mountain operation will produce doré bars on site, which will then be shipped to an out of state refinery. There is currently no contract in place with any refinery or buyer for the doré.

16.2 Market Studies

No market studies have been completed. Gold and silver are freely-traded commodities. The doré that will be produced by the mine is considered to be readily marketable with no deleterious/penalty elements. Although mercury is present in the ore, a retort and recovery system has been included to maintain doré quality.

The doré bars are forecast to have a variable gold and silver content with an expected gold to silver ratio of 44–49% gold to 51–56% silver.

The economic analysis in Section 19 assumes that Paramount will be paid 99.9% of the gold value and 99.5% of the silver value by a refinery (Table 16-1). Ausenco conducted a benchmarking analysis that estimated refining charges of $5/oz payable gold and $0.50/oz payable silver, totaling direct refining costs of $2.0 million over the LOM.

Table 16-1: Estimated Payability and Refining Costs

Description		Units		Value
Proportion of Au		Percent by weight content in doré bars			46
Proportion of Ag		Percent by weight content in doré bars			54
Payable gold		%			99.9
Payable silver		%			99.5
Refining and sales charges Au		$/oz			5.00
Refining and sales charges Ag		$/oz			0.50

16.3 Metal Pricing and Projections

16.3.1 Economic Analysis

Project economics were estimated based on long-term flat metal prices of $3,600/oz Au, and $48.00/oz Ag, which are based on consensus forecasts from various financial institutions.

The QP notes that the pricing used in the cash flow analysis is reasonably aligned with various long-term forward-looking estimates from major international banks.

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Metal prices are defined daily by several commodity markets via contract trading. Some of these markets are the London Metal Exchange (LME), the Commodity Exchange (COMEX), the New York Mercantile Exchange (NYMEX), the Chicago Mercantile Exchange (CME), and the London Bullion Market Association (LBMA).

Some exchanges define prices on the spot while others, like the LBMA, set prices based on offer and demand in the morning (AM) and in the afternoon (PM). Prices are set each day, except weekends and holidays. The gold and silver PM contract values are used to define future and expected gold prices.

Given the volatility of the metal prices, medium term average gold and silver prices are often used to inform the basis metal prices for economic analysis. The tables below show the average prices calculated for each time frame based on the PM daily gold prices set at the (LBMA).

Table 16-2: Gold Price Average (LBMA PM), $/oz

Date		High (1-yr)				Low (1-yr)				1-yr Avg				2-Yr Avg				3-yr Avg
May 26 ‘26			5,297.87				3,273.17				4,152.49				3,440.98				2,976.99

Table 16-3: Silver Price Average (LBMA PM), $/oz

Date		High (1-yr)				Low (1-yr)				1-yr Avg				2-Yr Avg				3-yr Avg
May 26 ‘26			118.45				32.90				59.69				45.45				38.37

Based on long-term analysis and industry consensus, median analyst metal prices were selected as representative for the economic analysis. The gold and silver prices used in the economic analysis are:

• Gold price: $3,600/oz

• Silver price: $48.00/oz

Metal prices were kept constant throughout the life of the Project.

16.3.2 Metal Pricing Forecasts

Paramount expects to commence production at Grassy Mountain within four years. Mid-term gold price forecasts by several institutions are listed in Table 16-4, seen to be in a similar range as those applied in the base case scenario in the FS.

Table 16-4: Mid-term gold price estimate by year from various organizations

Year		Units				2026				2027				2028				2029				Long-Term
Max		$	/oz Au				6,000				6,500				6,000				5,500				4,909
Min		$	/oz Au				3,600				3,600				3,600				3,022				2,500
Average		$	/oz Au				4,760				4,799				4,372				4,036				3,603
Median		$	/oz Au				4,713				4,663				4,250				3,825				3,600

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16.4 Contracts

Paramount has no current contracts for property development, mining, concentrating, smelting, refining, transportation, handling, sales and hedging, forward sales contracts or arrangements.

It is expected that when any such contracts are negotiated, they would be within industry norms for projects in similar settings in the U.S.

16.5 QP Comment

The doré that will be produced by the planned operation is readily marketable with no deleterious/penalty elements.

Metal pricing used in the economic analysis in Section 19 are based long-term flat prices of $3,600/oz Au, and $48.00/oz Ag, which are based on consensus forecasts from various financial institutions.

The QP has reviewed commodity pricing assumptions, marketing assumptions, and the potential major contracts that may be entered into and considers the information acceptable for use in estimating Mineral Resources, Mineral Reserves, and in the economic analysis that supports the FS. The QP notes that the pricing used in the cash flow analysis is reasonably aligned with various long-term forward-looking estimates from major international banks.

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17 ENVIRONMENTAL STUDIES, PERMITTING, PLANS, NEGOTIATIONS OR AGREEMENTS WITH LOCAL INDIVIDUALS OR GROUPS

17.1 Introduction

Permitting activities began in 2012 with engagement with the state and federal agencies and collection of baseline data. The draft Consolidated Permit Application (CPA) was submitted to the Oregon Department of Geology and Mineral Industries (DOGAMI) in 2019 for review and comment by state agencies which were received by Calico and integrated into the final CPA. In December 2021, Calico submitted the final CPA to DOGAMI. Calico and DOGAMI have been working together as the draft permits have been developed and are in the process of being finalized. The package of draft permits was issued for public review on December 8, 2025. Final permits are anticipated to be issued by all required state agencies in the second half of 2026.

In December 2021, Calico submitted a Plan of Operation (PoO) to the BLM. The draft Environmental Impact Statement (EIS) was published for public comment on August 8, 2025 and the final EIS and record of decision was published on January 29, 2026. This record of decision provides federal authorization for the PoO following posting of a reclamation bond.

The mine plan includes a total of approximately 490 acres of proposed surface disturbance including approximately 470 acres of disturbance occurring on public land (Table 17-1).

Table 17-1: Surface Disturbance for the Proposed Project

Component		Public Acres				Private Acres				Total Acres
Underground Mine			0.5				6.2				6.7
TSF			99.8				0.0				99.8
TWRSF			5.7				0.0				5.7
Process Plant1			2.5				0.0				2.5
Infrastructure & Ancillary Facilities2			17.8				0.0				17.8
Roads			31.6				3.3				34.9
Yards & Laydown Areas			9.9				0.1				10.0
Growth Media Stockpiles			7.7				0.0				7.7
Water Supply3			7.9				0.0				7.9
Power Supply4			61.1				0.0				61.1
Stormwater Diversion Channels			11.6				0.2				11.8
Quarry			48.2				0.0				48.2
Reclamation Borrow Areas5			55.9				0.0				55.9

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Component		Public Acres				Private Acres				Total Acres
Monitoring			0.0				0.0				0.0
Exploration6			10.0				0.0				10.0
Disturbed Areas7			98.6				9.1				107.8
Total			469.0				18.9				487.9

1. Includes the mill, refining plant, administrative building, parking lot, security building, mining contractor yard, reagent storage, assay laboratory, and substation.

2. Includes the perimeter fence at 22,176 ft with a 20-ft construction disturbance width.

3. Includes the water supply pipeline at 16,164 ft with a 20-ft construction disturbance width and well locations each at 0.25 acre.

4. Includes 20-ft area of disturbance for the 25.2 miles of new powerline.

5. The area of disturbance for the Reclamation Borrow Area is the maximum area of disturbance.

6. The actual location of the exploration activities within the Project Area is currently unknown and is assumed to be equally on public and private lands. Annual exploration work plans will be submitted and reviewed by BLM and DOGAMI as defined at 43 CFR 3809.0-5.

7. Disturbed Area is a 50-ft buffer on the mining facilities excluding the Reclamation Borrow Areas.

Table 17-2: Permitting

Permit/Approval		Granting Agency		Permit Purpose
Plan of Operations/EIS Record of Decision		BLM		Prevent unnecessary or undue degradation associated with Plan of Operations, EIS to disclose and evaluate environmental impacts and project alternatives. An EIS has been developed to analyze impacts of this Plan.
Oregon Department of Environmental Quality (ODEQ) Water Pollution Control Facility Permit and Water Pollution Control Facility-Individual Onsite system		ODEQ		Prevent degradation of waters of the state from mining, establishes minimum facility design and containment requirements. Regulates onsite septic system.
Standard Air Contaminant Discharge Permit		ODEQ		Regulates project air emissions from stationary and fugitive sources.
General Discharge Permit (Stormwater)		ODEQ		Protect waters of the state.
Oregon Water Resources Department (OWRD) Water Rights Amendment, Permit to Appropriate Water		OWRD		Water appropriation.
Public Drinking Water System (Non-Transient Non-Community Water System)		Oregon Health Authority		Regulates drinking water treatment systems.
OWRD Dam Safety Permit		OWRD		Design and construction of embankments 10 ft or higher and store at least 9.2 acre ft of water.
Malheur County Land Use Compatibility Statement (LUCS)		Malheur County		Permitting or approval activities that affect land use are required by Oregon law to be consistent with local comprehensive plans and have a process for determining consistency.
Explosives Permit		United States Department of the Treasury, Bureau of Alcohol, Tobacco, Firearms, and Explosives		Storage and use of explosives.

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Permit/Approval		Granting Agency		Permit Purpose
Hazardous Waste Identification Number		United States Environmental Protection Agency		Registration as a conditionally exempt small quantity generator of wastes regulated as hazardous.
Aggregate Operating Permit Application		DOGAMI		Operation and closure of the Basalt Quarry.
Chemical Process Mines Permit (Division 37)		DOGAMI		Operation and closure of the Project.
Chemical Mining Permit (Division 43)		ODEQ		Operation and closure of the Project.
2920 Permit – Leases, Permits and Easements*		BLM		Allow for the access road improvements and power line installation on property controlled by others

Note: * 2920 Permit required for a portion of Dripping Springs Road improvement.

17.2 Permit History

Permitting activities for the Grassy Mountain Project have spanned 30 years and includes multiple environmental permits for the purposes of exploration and investigation to support the development of the CPA and PoO. During the late 1980s Atlas collected geologic, mine engineering, civil engineering, and environmental baseline data to support a feasibility study that was completed in 1990. During 2012 to 2016, Calico began the permitting process for an underground-mining operation at Grassy Mountain. Since the acquisition of Calico by Paramount in 2016, the permitting process has continued with DOGAMI, Malheur County, and the BLM including submittals of the PoO and CPA in December 2021 and the issuance of a record of decision by the BLM in January 2026.

17.3 Project Permits

There is a valid exploration permit with the DOGAMI and the BLM although exploration activities have concluded.

The Project will require a PoO and numerous state and local permits to construct, operate, and close presented in Table 17-2.

Since the acquisition of Calico by Paramount in 2016, the permitting process has continued with DOGAMI, Malheur County, and the BLM including submittals of the PoO and CPA in December 2021. The BLM issued the final EIS and record of decision in January 2026. Malheur County issued a CUP for the Private Land portion of the Grassy Mountain Project in May of 2019. Draft state permits were issued for public comment and review in December 2025 and state agencies are currently in the process of finalizing permits. State permits will be issued at one time and are anticipated to be issued in the third quarter of 2026.

17.4 State of Oregon Permit Processing

Calico entered into a Memorandum of Understanding for Cost Recovery (MOU) with the Oregon DOGAMI on November 3, 2014. A new MOU was signed when the initial CPA CPA was submitted in November 2019. The MOU provides a mechanism whereby Calico, as the Project proponent, agrees to reimburse DOGAMI and other primary State agencies for their involvement in processing the CPA for the Grassy Mountain Project when those fees exceed their permit fees. In addition, DOGAMI hired consulting firms to provide expertise that is not available from the staff that the various agencies are involved with during the permitting process.

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The key components of the permitting program with the State of Oregon are as follows:

• Environmental baseline studies for all resource categories described in Chapter 632, Division 37 Chemical Process Mining Rules.

• Meeting all requirements of Division 37 Rules which include, but are not limited to:

• Preparation of a Consolidated Permit Application (CPA)

• Obtaining all necessary federal, state, and local permits and authorizations

• Satisfying any potentially applicable environmental evaluation requirements.

• Implementing a pro-active community involvement and consultation process including:

• Local hire preference

• Local contracting and purchase where practicable

• Mine worker job training to provide an experienced workforce.

A key authorization permit which will be required is the permit for Chemical Processing Mining, as required under Chapter 632, Division 37, 1991 Oregon Laws (§632-037-0005). The Consolidated Permit also requires approval by ODEQ under Division 43, Chemical Mining Rules (OAR 430-043-000), which address other environmental stipulations. “Chemical Process Mining” means a mining and processing operation for metal-bearing ores that uses chemicals to dissolve metals from ore. The Calico processing facility will employ cyanide in the metallurgical process. The Division 37 Rules provide a well-defined regulatory pathway with definitive permitting requirements and timelines.

Calico has filed multiple Notices of Intent (NOIs) under Division 37, which initiate the State permitting process and begin baseline data collection. The reason for the multiple NOIs is that the scope of the operation, as well as the configuration of the Project area have changed. Each change requires the submittal of a new NOI and a re-initiation of the permitting process. In addition, the initial NOI filing was done to initiate the agency Division 37 permit process and provide for public notice that the Project is proceeding into the permitting phase. As part of initiating the public notification, an interagency “Technical Review Team” (TRT) was organized to provide interdisciplinary review of technical permitting issues for the State Consolidated Permitting Process. This TRT has met numerous times and accepted the NOIs.

In addition, DOGAMI administrators and the TRT have reviewed and approved the “Calico Resources Environmental Baseline Work Plans Grassy Mountain Mine Project”, which was filed on May 17, 2017. In July 2017 a “Notice of Prospective Applicant’s Readiness to Collect Baseline Data” was issued to Calico by DOGAMI. The environmental baseline data collection and reporting program is now complete. All Baseline Data Reports (BDRs) submitted by Calico have been accepted by the TRT. The three most current approvals were for the Wildlife Resources BDR accepted in March 2021, the Geochemistry BDR accepted in June 2022 and the Groundwater BDR accepted in June 2022. The Cultural Resources BDR is confidential and relies on the SHPO to provide a recommendation to the TRT.

Calico prepared and submitted the Division 37 CPA for the Grassy Mountain Gold Mine in November 2019. This single application, as required under Oregon laws, included the following elements:

• General information

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• Existing environment-baseline data

• Operating plan

• Reclamation and closure plan

• Alternatives analysis.

DOGAMI finished their completeness review with input from the TRT. DOGAMI determined that additional information was necessary before further processing of the application. Comments were received in February 2020. Calico submitted the Revised CPA package to DOGAMI in December 2021. Calico has been working with DOGAMI since the submittal responding to questions and comments. The air application was submitted separately in August 2022.

A Notice to Proceed with the preparation of draft permits was issued by DOGAMI in November 2023. This notice included a directive by DOGAMI to use the third-party contractor to prepare an Environmental Evaluation (EE), which was accepted by the TRT in October 2024. This EE is not a Federal NEPA requirement. It is a State of Oregon requirement which includes:

• Impact analysis

• Cumulative impact analysis

• Alternatives analysis (OAR 632-037-0085).

Concurrent with this assessment, DOGAMI utilized the contractor to prepare a Socioeconomic Analysis. This analysis identified major and reasonably foreseeable socioeconomic impacts on individuals and communities located in the vicinity of the proposed mine. In particular, the analysis will describe impacts on population, economics, infrastructure, and fiscal structure (OAR 632-037-0090).

This process for permit review and approval involved a consolidated public hearing on all draft permits, and the draft operating permit which was conducted on January 29, 2026 in Vale, Oregon. Other applicable State of Oregon and Federal permits may include, but are not limited to the following:

• Permits to appropriate groundwater or surface water, or to store water in an impoundment (ORS 537.130, ORS 537.400, and ORS 540.350)

• Water Pollution Control Facility (ORS 468B.050)

• Storm Water Pollution Prevention Plan (EPA)

• Air Quality Permits (ORS 468A.040)

• Solid Waste Disposal Permit (ORS 459.205)

• Permit for Placing Explosives (ORS 509.140)

• Hazardous Waste Storage Permit (OAR 340-102-0010)

• Land Use Permit (OAR Chapter 632, Division 001)

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• Any other State permits, if applicable and required under Division 37.

A Project Coordinating Committee (PCC) was also formed for the purpose of sharing information; further coordinating the Federal, State, and local permitting requirements; optimizing communication; facilitating the regulatory process; and avoiding duplicative effort. The PCC has met formally and conducted a series of public meetings in Ontario and Bend, Oregon. These meetings were attended by agencies, public officials, Project supporters, and non-governmental organizations (NGOs).

Division 37 mandates DOGAMI to manage and facilitate the regulatory permitting process. It requires that a series of public meetings are held, to be coordinated by DOGAMI or its contractor. This committee is charged with gathering comments from the public regarding Project specifics. DOGAMI acts as the facilitating State agency and State clearinghouse for the mine permitting process. It is the applicant’s responsibility to secure other needed State permits such as air pollution control, storm water pollution prevention plan, and land use permits as may be required. However, the Division 37 process is designed to promote a consolidated permitting pathway.

DOGAMI coordinates with the other agencies to avoid duplication on the part of the applicants and related agency requests. The agency is also responsible for reviewing mine operating plans and issuing reclamation permits. It establishes reclamation bond amounts for the Project, working closely with Calico.

The basic information for a Division 37 application involves:

• Determining existing environmental baseline conditions

• Providing an operating plan (mine plan and reclamation/closure plan)

• Providing an alternatives analysis

• Providing an environmental evaluation

• Providing a socio-economic impact analysis

• Developing a plan to minimize pollution and erosion

• Protecting fish and wildlife during operations and closure (fish and wildlife standards)

• Providing a water balance

• Establishing financial assurance requirements

• Inclusion of all other State, Federal, and local permit applications required under Division 37.

Draft state permits are anticipated to be issued in the second half of 2026.

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17.4.1 Federal Plan of Operations Processing

A PoO must be submitted to the BLM for any surface disturbance in excess of five acres. A PoO describes the operational procedures for the construction, operation, and closure of a project. The PoO must also include a waste rock management plan, quality assurance plan, a storm water plan, a spill prevention plan, reclamation plan and cost estimate, a monitoring plan, and an interim management plan. The content of the PoO is based on the mine plan design and the data gathered as part of the environmental baseline studies. The PoO includes all mine and processing design information and mining methods. The BLM determines the completeness of the PoO and, when the completeness letter is submitted to the proponent, the NEPA process begins.

The initial submittal of the Grassy Mountain PoO was in September 2017. A revised PoO was submitted to the BLM in February 2020. The BLM determined the PoO submitted in February 2020 was not complete and requested additional details. Calico submitted a new PoO in December 2021 and that the BLM determined was incomplete and provided comments to Calico in March 2022. Calico responded to the comments in July 2022 and received further input from the BLM in September 2022. The final PoO will be submitted to the BLM in October 2022 and based on input received from the BLM, acceptance of the PoO triggering the NEPA process.

17.4.1.1 National Environmental Policy Act

The NEPA process is triggered by a Federal action. In this case, the issuance of a completeness letter for the PoO triggered the Federal action. The BLM determined that the NEPA review process for this Project was an EIS.

The EIS process was conducted in accordance with NEPA regulations (40 CFR 1500 et. Seq.), BLM guidelines for implementing the NEPA in BLM Handbook H-1790-1 (updated January 2008), and BLM Washington Office Bulletin 94-310. The intent of the EIS is to assess the direct, indirect, residual, and cumulative effects of a project and to determine the significance of those effects. Scoping is conducted by the BLM and includes a determination of the environmental resources to be analyzed in the EIS, as well as the degree of analysis for each environmental resource. The scope of the cumulative analysis is also addressed during the scoping process. Following scoping and baseline information collection, a draft EIS is prepared and submitted to the public for review which occurred on August 8, 2025 followed by a public meeting held in Vale, Oregon on August 28, 2025. Comments received from the public were incorporated into the final EIS, which is in turn updated by the BLM prior to the issuance of a record of decision. the final EIS and record of decision were issued on January 29, 2026 completing the federal permitting process.

17.4.2 Malheur County Permit Processing

Malheur County requires the authorization of a CUP for the Private Land part of the Grassy Mountain Project. Calico obtained the CUP in May of 2019. Additionally, building permits from the Malheur County will also be required to address plumbing, electrical, and structural design.

17.5 Environmental Study Results and Known Issues

17.5.1 Baseline Studies

Paramount has been conducting baseline data collection for over ten years for environmental studies required to support the State and Federal permitting process. Results indicate limited biological and cultural issues, air quality impacts appear to be within State of Oregon standards, traffic and noise issues are present but at low levels, and socioeconomic impacts are positive. The result of the geochemical characterization identified that the geochemistry of the ore and waste rock provide for a possible source of future environmental issues as the Grassy Mountain Project is developed.

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Data produced during the baseline and geochemical studies were used in the Project design process, including the design and operation of the TSF and handling and use of waste rock as cemented backfill material, specifically considering environmental impacts. As outlined in Section 15, the design of the TSF and the waste rock management plan used the results of this geochemical characterization work.

The following baseline studies have been submitted to the BLM and DOGAMI as part of the permitting process:

• Air Quality Resources Baseline Report

• Aquatic Resources Baseline Report

• Areas of Critical Environmental Concern Research Natural Areas Baseline Report

• A Cultural Resource Inventory of 830 Acres for the Grassy Mountain Mine Project (withheld from public review)

• Environmental Justice Baseline Report

• Baseline Geochemical Characterization Report

• Geology and Soils Baseline Report

• Grazing Management Baseline Report

• Grassy Mountain Gold Project Baseline Groundwater Reports

• Land Use Baseline Report

• Noise Baseline Report

• Oregon Natural Heritage Resources Baseline Report

• Outstanding Natural Areas Baseline Report

• Recreation Baseline Report

• Socioeconomics Baseline Report

• Surface Water Baseline Report

• Terrestrial Vegetation Baseline Report

• Transportation Baseline Report

• Transportation Baseline Traffic

• Transportation Baseline Trip Generation

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• Visual Resources Baseline Report

• Wetland Delineation Report

• Wild, Scenic, or Recreational Rivers Baseline Report

• Wildlife Resources Baseline Report

All BDR submitted by Calico have been accepted. The Cultural BDR is handled confidentially and separately by the BLM. The SHPO is expected to make a recommendation to the TRT; the TRT will not review the report itself, nor will it be available for public comment.

17.5.2 Geochemical Characterization and Groundwater Studies

The geochemical characterization and groundwater studies are interrelated studies with both focused on predicting the potential for acid rock drainage on the surface and in groundwater primarily due to the storage of tailings and the storage and use of waste rock as backfill. Paramount, DOGAMI, and the BLM have worked together to ensure the baseline reports including geochemical and hydrogeological characterization and modeling is sufficient for the PoO and CPA to be accepted and move forward in the permitting process. The final reports were submitted to DOGAMI and BLM in 2022.

SRK Consulting U.S., Inc. (SRK) completed the baseline geochemical characterization study for the Grassy Mountain Project in 2022. The purpose of the baseline geochemical characterization program was to provide a prediction of the potential geochemical reactivity and chemical stability of mine waste that will be produced by the Grassy Mountain Project. The results of the geochemical characterization program assisted in determining the potential for acid rock drainage (ARD) and metal leaching (ML) associated with the Grassy Mountain Project. Data produced during this study were used in the Grassy design process and as an operational tool for identifying material types that require special handling during operations. As outlined in Section 15 of the Report, the design of the TSF and the waste rock management plan used the results of this geochemical characterization work.

The Grassy Mountain Project waste rock shows variable geochemical behavior and each material type has a wide range of sulfide content and predicted acid generation from the static test results. Overall, the waste rock has very limited acid neutralizing capacity due to the low inorganic carbon content and as such the predicted acid generating potential is strongly related to sulfide content. The characterization results for the ore grade material are comparable to the waste rock material.

Based on the acid–base accounting (ABA) and net-acid generating (NAG) results, six out of the 104 waste rock and ore samples contain greater than 0.5% sulfide sulfur indicating a higher potential for acid generation. The remaining samples have an uncertain potential for acid generation with net-neutralizing potential (NNP) values between -20 and 20 kg CaCO₃ eq/ton. The NAG results are consistent with the ABA data and show samples with sulfide sulfur greater than 0.5 wt% are predicted to have a higher capacity for acid generation with NAG values greater than 20 kg H₂SO₄ eq/ton. Samples with sulfide sulfur content between 0.05 and 0.5 wt% show a low to moderate potential for acid generation with NAG values between 1 and 20 kg H₂SO₄ eq/ton.

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Based on a meteoric water mobility procedure test, the majority of the samples have neutral to alkaline paste pH values (pH 6–8), indicating minimal readily-soluble acid sulfate salts from prior oxidation of the core material. The exceptions are a few samples of mudstone and siltstone with the highest sulfide sulfur content that generated acidic leachate. Constituents above Oregon groundwater quality guidelines under the low pH conditions include sulfate, arsenic, cadmium, chromium, copper, fluoride, iron, manganese, selenium and zinc. For samples with neutral pH (i.e., pH >7) all constituents were below the Oregon groundwater quality guidelines.

Eight of the 10 humidity cell tests generated acidic leachate throughout the test and indicate that samples with an uncertain potential for acid generation from the ABA will generate acid under long term weathering conditions. The only two samples that maintained neutral conditions during the humidity cell test program consisted of sinter material. All other material types are considered to be acid generating including the sandstone, siltstone and mudstone. A comparison of the HCT leachate chemistry to Oregon groundwater quality guidelines indicates the mudstone (HC-3 and HC-4) had the greatest number of parameters that exceeded guidelines and the sinter cells (HC-8 and HC-9) had the least. Most cells that developed acidic conditions leached copper, iron, manganese, arsenic and sulfate at concentrations greater than the guidelines, indicating these elements are mobile under acidic pH conditions. Other constituents that were leached above Oregon groundwater quality guidelines during the first few weeks of the test include cadmium, chromium, copper, fluoride, lead, selenium, silver and zinc.

17.6 Waste Disposal, Monitoring, Water Management

Waste rock characterization has been conducted and results indicate that the waste rock and ore are generally reactive, acid generating, and have the potential to leach metals (refer to Section 17.4). As a result, waste rock and tailings management have been and will remain key issues in the permitting of the mining operation. The TSF design, as described in Section 15, was developed to mitigate the risk of groundwater impacts due to tailings storage and includes drainage layer for solution capture and repurposing, a dual liner, and leak detection. The waste rock generated during the operation will be temporarily stored on a dual lined facility prior to utilization as cement rock fill (CRF), as described in Section 15.

Paramount has developed and submitted to BLM and DOGAMI for approval, the following monitoring and management plans associated with waste disposal:

• Stormwater Management Plan

• Waste Management Plan

• Groundwater and Facilities Monitoring Plan

• Cyanide Management Plan

• Petroleum-Contaminated Soil Management Plan

• Tailings Chemical Monitoring Plan

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17.7 Social and Community Issues

Social and community impacts have been considered and evaluated for the PoO in accordance with the NEPA and other Federal laws, and the State of Oregon Socioeconomic Analysis. Potentially affected Native American tribes, tribal organizations and/or individuals were consulted during the preparation of the PoO and consultation continues to advise on the project that may have an effect on cultural sites, resources, and traditional activities.

The most recent planning by Malheur County, Oregon, were considered during the preparation of PoO and CPA. Potential community impacts to existing population and demographics, income, employment, economy, public finance, housing, community facilities and community services will be evaluated for potential impacts as part of the State of Oregon and the NEPA process.

There are no known social or community issues that would have a material impact on the Project’s ability to extract Mineral Resources and Mineral Reserves. Identified socioeconomic issues (employment, payroll, services and supply purchases, and State and local tax payments) are anticipated to be positive through the creation of direct, indirect and induced jobs.

Paramount plans to implement a proactive community involvement and consultation process including 1) local-hire preference; 2) local contracting and purchasing where practicable; and 3) mine-worker job training to provide an experienced work force. Mining and milling jobs are expected to be sourced to local communities where possible, with limited relocation to supply the expertise reinforcing the local skillsets.

As a commitment to the local community, Paramount has conducted site tours and discussions with the state and local senators, representatives, regulators and the local school high school regarding the project. Paramount also has plans to further partnerships with local community colleges and vocational schools whereby “mining expertise” can be developed through partnership curriculums. These partnerships are likely to include Treasure Valley Community College in Ontario, Eastern Oregon University in LaGrande, and College of Western Idaho in Boise. Paramount will coordinate with Eastern Oregon University to develop and provide the MSHA safety training program.

17.8 Closure

A closure plan and RCE were submitted to the BLM and DOGAMI as part of PoO and CPA, respectively. The proposed reclamation approach for the Project includes sealing the mine portal, lining, capping, and revegetating the TSF supported by temporary active solution management followed by passive solution management (evaporation) as the TSF drains down, the removal and offsite disposal of the temporary waste rock storage facility liner, process plant and other infrastructure, the demolition and offsite disposal of the powerline and associated infrastructure, and in general the grading, capping, and revegetation of disturbed areas. This approach will result in two post-reclamation landforms, the TSF and the quarry, and is anticipated to be completed within five years of ceasing operation. Post-reclamation monitoring, including groundwater and stormwater quality and revegetation success, is proposed to meet Federal and State requirements and guidance and will be continue for up to 30 years following reclamation.

The RCE was developed using the Nevada Standardized Reclamation Cost Estimator (SRCE Version 2.0) and includes direct and indirect costs, contingency, and post-reclamation monitoring assuming third-party costs. The RCE was updated in February 2026 to account for current unit rates and in response to input from DOGAMI and BLM during the permitting process. The reclamation surety associated with the proposed reclamation plan is $21,086,123 including indirect costs such as contingency, contractor management and contractor profit. The BLM and State of Oregon are in negotiations to establish an MOU allowing the State of Oregon to hold the bond and oversee the reclamation activities.

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17.9 Environmental and Permitting Risks and Opportunities

As with almost all mining projects, there are inherent risks and opportunities related to the final outcome of the Project. Most of these risks related to environmental and permitting are based on uncertainty of the permitting program, and timing to obtain all necessary permits and authorizations. Other risks can involve new regulations, the modifications of environmental standards like air or water quality, and legal challenges; however, the Project has limited applicable environmental standards as it relates to water quality (groundwater and surface water).

To facilitate Project permitting and development for the FS and permitting programs, and to design a sustainable project and reduce environmental risks, Paramount adopted the following environmental principles for the Project:

• Confirm the presence of potential threatened and endangered or sensitive amphibians, wildlife, or plant species at the site.

• Reduce the area of disturbance where possible by utilizing existing infrastructure and re-use of waste rock as backfill.

• Reduce environmental impacts such as emissions, noise and vibration, water consumption, etc. through operational controls such as limiting traffic to and from the site and the re-use of water from the underground and TSF.

• Protect local surface and ground water quality and quantity by applying best management practices and evaluating and implementing new practices as they are identified.

• Effectively manage all related mine waste including lining the TSF and use of waste rock underground as backfill.

• Reduce the carbon footprint for the Project by processing the gold concentrate on site.

• Conduct environmental monitoring to ensure compliance with all applicable State, Federal, and local laws, regulations, and ordinances.

• Transport all fuel to the mining operation according to accepted transport and spill prevention and response standard operating procedures developed specifically for the Project.

• Integrate pro-active wildlife habitat mitigation and enhancement proposals with an environmentally responsible reclamation plan.

• Provide adequate financial assurance for implementing an effective reclamation plan to ensure long-term protection and rehabilitation of the mine site.

• Implement a responsible community and statewide public affairs program to further open communications, maximize local job opportunities and involvement, and meet environmental justice requirements for the Grassy Mountain Mine Project.

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Collectively, these objectives or environmental principles will guide Project development. They will also serve to reduce risk and enhance related Project opportunities.

17.10 Qualified Person’s Opinion

The final EIS and record of decision were issued in January 2026 providing federal authorization for the PoO to progress into construction, operation and closure. State permits authorizing the mine plan to progress are expected to be provided in the second half of 2026. Paramount’s engagement with the local, state, and federal regulatory agencies as well as the local community and tribal engagement has been frequent resulting in a supportive local community and strong working relationship with the regulatory agencies.

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18 CAPITAL AND OPERATING COSTS

18.1 Capital Cost Estimate

18.1.1 Introduction

The capital cost estimate was developed with an accuracy of ±15% using the AACE Class 3 estimate standards, and includes the cost to complete the design, procurement, construction and commissioning of all the identified facilities.

The entities involved in the estimate and their specific areas of input are summarized in Table 18-1.

Table  18-1: Capital Cost Estimate Input Areas

Company Responsible		Area		Item
Ausenco		Site development & earthworks		• Internal roads • Catchment pond • Diversion ditches from process plant to pond • Crusher ROM pad • Plant site bulk earthworks • On-site infrastructure bulk earthworks
		Crushing & material handling		• Primary crushing • Secondary crushing • Fine ore bin
		Process plant		• Grinding and classification • Carbon-in-leach • Cyanide detox • Carbon elution and gold room • Reagents • Process utilities (process plant building, water systems, plant & instrument air, process control system)
		Tailings management & waste rock		• Tailings & reclaim water pipelines
		On-site infrastructure & utilities		• Power distribution (power distribution & supply, electrical rooms, control rooms) • Water supply & distribution • Waste management (water treatment plant (grey water)) • Ancillary buildings (mine dry & office, mine maintenance/warehouse, underground truck shop, plant maintenance/warehouse, assay laboratory) • Surface mobile equipment (surface mobile equipment & facilities) • Bulk fuel storage & distribution • Information technology and communications

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Company Responsible		Area		Item
RESPEC		Mining pre-stripping		• Portal construction • Portal laydown
		Mine development		• Decline • Level station • Level access • Underground sump • Underground stockpiles • Underground power stations • Underground truck loading bays • Ventilation infrastructure (ventilation bays, raises)
		Underground mine equipment		• Surface and Underground mobile equipment
		Mine infrastructure & services		• Main fans and housing • Auxiliary fans
		Mine dewatering		• Face pumps • Sump pumps
		Backfill plant		• Surface backfill plant infrastructure
		Haul roads		• Portal to WRSF • Ventilation laydown • Powder magazine • Borrow pit road
Golder		Tailings facility & water management		• Construction material quantity estimate only
		Reclamation & closure		• Inputs to SRCE model
R&O Consulting (R&O)		Site access road		• Main access roads
SPF Water Engineering (SPF)		Water distribution		• Water distribution and management
Fire Safety Systems Ltd (FSS)		Fire systems		• Fire suppression, detection and protection systems
Idaho Power		Powerlines		• Main substation and power line to site
Paramount Gold		Owner’s costs		• Owner’s costs and inputs to G&A

18.1.2 Cost Estimate Summary – Initial Capital

The estimate is derived from budgetary pricing for major items in the mechanical equipment list, electrical equipment list and contractor work packages (e.g. concrete, structural steel, platework, etc.), benchmarked against similar projects and scaled/escalated accordingly. The estimates were based on a number of fundamental assumptions as indicated in process flow diagrams, general arrangements, material take offs (MTOs), cable schedules, scope definition and a work breakdown structure. The estimate included all associated infrastructure as defined by the scope of work developed in 2020 FS and carried in the 2022 FS update.

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The capital cost estimate is summarized in Table 18-2 and Table 18-3. The estimate has a base date of Q1, 2026 with no provision for forward escalation and noted in US dollars unless stated otherwise.

Table 18-2: Initial Capital Cost Estimate Summary (direct and indirect)

WBS		Description		$ M		% of Total Costs
1000		Mining		26.2		14
2000		Site development		7.2		4
3000		Mineral processing		43.4		23
4000		Tailings management & waste rock facility		13.3		7
5000		On-site infrastructure		17.3		9
6000		Off-site infrastructure		16.8		9
Direct Subtotal				124.6		66
7000		Project indirect costs		28.0		15
9000		Owner’s costs		15.6		8
Indirect Subtotal				43.6		23
8000		Provisions (Contingency)		19.8		10
N/A		Capitalized Operating cost		1.7		1
Project Total – Initial Capital				189.8		100

Note: totals may not match due to rounding

Table 18-3: Initial Capital Cost Estimate by Major Discipline

Disc.		Major Discipline		$ M
A		Architectural			8.6
B		Earthworks			6.5
C		Concrete			4.1
S		Structural steelwork			2.8
F		Platework			4.9
M		Mechanical equipment			20.5
P		Piping			3.9
E		Electrical equipment			8.2
L		Electrical bulks			2.3
I		Instrumentation			0.6
N		Mobile equipment			2.1
R-1		Third party estimates			60.0
Direct Subtotal					124.6
O		Owner’s costs & bonding			15.7
R-2		Third party estimates			2.0

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Disc.		Major Discipline				$ M
T			Project delivery (EPCM)				20.1
U			Field indirects				2.2
V			Spares & first fills				3.7
Indirect Subtotal							43. 6
Y			Provisions (Contingency)				19.8
N/A			Capitalized Operating cost				1.7
Project Total – Initial Capital							189.8

18.1.3 Cost Estimate Summary – Sustaining Capital

The sustaining capital cost estimate is provided in Table 18-4 and includes costs for mining operations (equipment lease), mineral processing, tailings management and site infrastructure over the LOM.

Table 18-4: Sustaining Capital Cost Estimate Summary (direct and indirect)

WBS		Description		$ M
1000		Mining			33.4
2000		Site development			—
3000		Mineral processing			3.9
4000		Tailings management & waste rock facility			20.4
5000		On-site infrastructure			—
6000		Off-site infrastructure			—
Direct Subtotal					57.7
7000		Project indirect costs			1.7
9000		Owner’s Costs			2.4
Indirect Subtotal					4.1
8000		Provisions (Contingency)			3.3
Project Total – Sustaining Capital					65.1

Note: totals may not match due to rounding

18.1.4 Definition of Costs

The capital cost estimate was developed for initial and sustaining capital, broken out into direct and indirect costs:

• Initial capital is the capital expenditure required to start up a business to a standard where it is ready for initial production.

• Sustaining capital is the capital cost associated with the periodic addition of new plant, equipment or services that are required to maintain production and operations at their existing levels, or a TSF expansion.

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• Direct costs are those costs that pertain to the permanent equipment, materials and labor associated with the physical construction of the process facility, infrastructure, utilities, buildings, etc. Contractor’s indirect costs were contained within each discipline’s all-in rates.

• Indirect costs include all costs associated with implementation of the plant and incurred by the Owner, engineer or consultants in the project design, procurement, construction, and commissioning.

18.1.5 Methodology

The estimate was updated in Q2 2026 based on a mix of budgetary quotations for major equipment supply, detailed material take-offs and engineered/factored quantities and costs, and detailed unit costs supported by contractor bids, consistent with AACE Class 3 estimating guidelines.

The estimate was based on an engineering, procurement and construction management (EPCM) approach where the EPCM contractor will oversee the delivery of the completed project from detailed engineering and procurement to the transfer of a working facility. The EPCM contractor shall engage and coordinate several subcontractors to complete all work within the given scopes.

The structure of the estimate was a build-up of the direct and indirect cost of the current quantities; this included the installation/construction hours, unit labor rates and contractor distributable costs, bulk and miscellaneous material and equipment costs, any subcontractor costs, freight and growth.

The craft wages carried in the estimate were calculated based on current contractor bids and adjusted to align with current industry rates for the project area. The labor rates reflect the composition of the project location using local Oregon labor and other surrounding regional workforces from neighboring states.

Percentages were added to the base labor rate for concrete, structural, mechanical, piping, electrical and instrumentation whilst earthworks was based on sub-contractor rates. Distributable costs were allocated by percentage per discipline based on Ausenco’s historical data confirmed by back calculating contractor indirect costs from the returned bids.

Mechanical and electrical equipment were updated to a Q2 2026 basis with pricing for major equipment based on budget quotations. Other minor equipment costs were from historical data from recent projects and studies or developed using engineering estimates.

18.1.6 Exchange Rates

The exchange rates used were determined from the XE.com website as of March 1, 2026 and were applied to foreign currency data. The exchange rates in Table 18-5 were used.

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Table 18-5: Exchange Rates used in the FS

Forex Rate		USD
1.000 CAD			0.733
1.000 AUD			0.711
1.000 USD			1.000

Note: CAD = Canadian dollar, AUD = Australian dollar, USD = US dollar

18.1.7 Market Availability

The pricing and delivery information for quoted equipment, material and services was provided by suppliers based on the market conditions and expectations applicable at the time of estimated development.

Market conditions are susceptible to the impact of demand and availability at the time of purchase and could result in variations in the supply conditions. The estimate in this report is based on information provided by suppliers and assumes that current challenges faced with the supply and availability of equipment and services are not applicable during the proposed execution phase.

18.1.8 Mining Capital Cost Estimate

18.1.8.1 Underground Capital Costs

The underground capital costs were estimated using quotes and InfoMine cost estimates. The underground capital costs are listed in Table 18-6.

Table 18-6: Underground Capital Costs

Equipment

Model

Quantity

Quote or Estimate

Buy or Lease

Total Cost ($ M)

Dual boom—development drill rig

Sandvik DD422i

3

Quote

Lease

4.9

Underground loader

Sandvik LH307

4

Quote

Lease

3.9

Truck with ejector bed

Sandvik TH320

3

Quote

Lease

3.2

Front-end loader (share with surface & underground)

CAT 962H

2

Quote

Lease

1.0

Powder loader

CAT 440

1

Quote

Lease

0.2

Telehandler

CAT TL1255

2

Quote

Lease

0.6

Dozer (share with surface & underground)

CAT D6T

2

Quote

Lease

1.2

Motor grader

CAT 160

1

Quote

Lease

0.8

Shotcrete Sprayer

GetMan Proshot Concrete Sprayer

1

Quote

Rent

0.8

Shotcrete Truck

GetMan ProMix 6

1

Quote

Rent

0.6

Lube Truck

Getman A64 SE Lube

1

Quote

Rent

0.6

Water Truck

Getman A64 SE Water Sprayer

1

Quote

Rent

0.5

Scissor deck

Getman A64 SE SL

1

Quote

Rent

1.2

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Equipment

Model

Quantity

Quote or Estimate

Buy or Lease

Total Cost ($ M)

Mine Rescue Truck6

Kovatera KT200

1

Quote

Rent

0.3

Diamond Drilling

Hydracore HC200UG

1

Estimate

Buy

0.3

Tractor

Kubota 5100

4

Quote

Buy

0.3

4WD Twin Cab Utility

Light Vehicle 4WD Twin Cab Utility 1/2 ton

3

Quote

Buy

0.3

Refuge Chambers

MineARC 16 person

2

Quote

Buy

0.2

Bio-Lavatories

MineARC EnviroLAV

4

Quote

Buy

0.1

UG Shop Equipment

Misc.

1

Estimate

Buy

0.7

Mine Remote Stench system

Remote and Manually

2

Quote

Buy

0.03

Main Fan

Spendrup 274-183-900-A- D

1

Quote

Buy

0.8

Main Fan Installation

Misc.

1

Quote

Buy

0.4

Auxiliary fans

JetAir Axiflow fan Model O-4150-B

5

Quote

Buy

0.2

Auxiliary pumps

Peak TD350HH

5

Quote

Buy

0.1

Pump Station supplies

Misc.

1

Estimate

Buy

0.2

Face pump

TD250HH 13HP

5

Quote

Buy

0.06

Initial supplies & inventory

Powder, bolts, pipe, inventory

1

Estimate

Buy

0.2

Mobile load center (electrical)

Intermountain Electrical Inc

3

Quote

Buy

0.7

Jumbo boxes

Terminator T2 Box

4

Quote

Buy

0.9

Portal preparation

Misc.

1

Quote

Buy

0.7

Capital Development Contractor Mobilization

Misc.

1

Quote

Buy

0.1

Compressed air

Sullair model LS16009 985 ACFM@125 PSIG

4

Quote

Buy

0.4

Spare parts – main fan

Spare main fan + starter

1

Quote

Buy

0.5

Spare parts – fans, MLC, jumbo box, compressor

—

1

Quote

Buy

0.1

Spare parts – pumps

—

1

Quote

Buy

0.04

Backfill plant

Master Plant – Simem WetBaton 100

1

Quote

Buy

1.8

Backfill Plant Addon for shotcrete

Simem

1

Quote

Buy

0.2

Installation

Misc

1

Estimate

Buy

0.9

Mine Dispatch System

GroundHog Enterprise SIC Software—Initial Setup

1

Quote

Buy

0.02

Mining Admin Office IT setup

Misc.

1

Estimate

Buy

0.04

Blast Logger iKon Logger

Orica iKon

3

Quote

Buy

0.01

iKon Blaster

Orica iKon Blaster 3000 or equivalent

2

Quote

Buy

0.02

Leaky Feeder system

Cable, Amplifier, Install

1

Estimate

Buy

0.2

Note: Costs are rounded; therefore, minor variances from actual costs may occur in the table.

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The capital costs are categorized into ‘buy’, ‘lease’, or ‘rent’. Items categorized as ‘lease’ will be lease-to-own. Items categorized as ‘rent’ will be rented for a period of three years, after which a lumpsum payment will be made to purchase them. A portion of those costs pertain to initial capital, and the remaining amount has been apportioned to sustaining capital. The summary for leasing costs by year is shown in Table 18-7.

Table 18-7: Underground Leasing Costs

Item		Unit				Year 0				Year 1				Year 2				Year 3				Year 4				Year 5				Year 6				Year 7				Year 8				Total
Down payment		$	M				1.7				1.5				0.0				0.0				0.0				0.0				0.0				0.0				0.0				3.2
Principal payment		$	M				0.4				1.7				2.3				2.5				2.7				2.3				0.7				0.0				0.0				12.8
Net capital		$	M				2.2				3.2				2.3				2.5				2.7				2.3				0.7				0.0				0.0				15.9
Interest payment		$	M				0.2				0.7				0.8				0.6				0.4				0.1				0.2				0.0				0.0				2.8
Total payments		$	M				2.4				3.9				3.1				3.1				3.1				2.4				0.7				0.0				0.0				18.7

Note: totals may not match due to rounding

18.1.8.2 Cost Estimate Summary (Mining)

Initial mining capital costs are summarized in Table 18-8.

Table 18-8: Initial Mining Capital Cost Estimate Summary

WBS		Description		$ M
1100		Mine portal construction			0.8
1200		Mine development/production			14.9
1300		Mine fixed equipment			1.6
1400		Mine infrastructure and services			0.9
1500		Mine fleet			4.0
1600		Mine dewatering			0.1
1700		Mine pre-production costs			0.2
1800		Backfill plant			1.9
2100		Bulk earthworks			0.8
2200		Road			0.3
7000		Other indirects			1.2
9100		Owner’s costs			0.8
8100		Contingency			2.5
Project Total – Initial mining-related capital costs					29.9

Note: Costs are rounded to the nearest million USD for reporting purposes; therefore, minor variances from the actual costs may occur in the table.

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18.1.9 Processing and Overall Site Infrastructure Capital Cost Estimate

18.1.9.1 Basis of Estimate Methodology

18.1.9.1.1 Direct Costs

Direct costs are quantity-based and include all permanent equipment and materials associated with the physical construction of the facility. Cost estimates include:

• Direct labor-hours and labor

• Contractor distributable

• Permanent equipment and bulk materials

• Freight and subcontracts.

18.1.9.1.2  Labor Productivity

Productivity factors were used to capture the productivity loss due to conditions experienced in the Project area.

Site productivity was assessed for each discipline using the scorecard method. Unit-labor hours were multiplied by the productivity factors for total labor-hours per line item. Total labor-hours were then compared against returned contractor bids to ensure sufficient labor-hours were carried in the estimate.

18.1.9.1.3  Contractor Labor Rates

The contractor labor wages carried in the estimate were calculated from a recently completed project by Ausenco in Washington State. The rates were benchmarked against historical data for labor in Oregon and Idaho. The labor rates reflect the use of local labor and surrounding regional workforces. The rates are fully burdened.

18.1.9.1.4  Contractor Distributable Costs

Percentages were added to the base labor rate for concrete, structural, mechanical, piping, electrical and instrumentation. Earthworks were based on sub-contractor rates. Distributable costs were allocated by percentage per discipline based on Ausenco’s in-house database and confirmed by back calculating contractor indirect costs from the returned bids.

18.1.9.1.5  Earthworks & Site Preparation

Items such as engineered fill are to be sourced from borrow pits and stockpiles on site. MTOs were taken from an Autodesk Civil 3D model of the plant layout and general arrangements.

Sub-contract rates were used in the estimate for bulk earthworks requirements. Prices carried in the estimate were a combination of rates from local contractors and Ausenco’s in-house database for benchmarking.

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18.1.9.1.6  Concrete Supply & Installation

The scope of the concrete works allows for all concrete work in the process plant and relevant on-site facilities. MTOs were prepared by engineering and are based on calculations derived from a 3D layout model, general arrangement drawings and sketches.

The basis for the development of installed concrete was the product of concrete material supply and installation costs. Labor costs included the necessary consumables, reinforcement bar, and formwork. Supply of ready-mix concrete costs were sourced from contractors in the area for current pricing and benchmarked against other reference projects in a similar geography. The overall unit rates were comparable to those in Ausenco’s in-house database for projects in Oregon and Idaho.

The cost of an on-site batch plant was excluded from the estimate as the mine site is located within driving distance to Vale and Boise. Both cities have existing ready-mix plants.

18.1.9.1.7  Structural Steel

Structural steel quantities were prepared by engineering based on calculations derived from a 3D layout model, general arrangement drawings and sketches.

The basis for the development of installed structural steel was the product of steel material supply and installation costs. Labor-hours were based on local contractors for the installation of the necessary structural sections and all associated items such as stair treads, hand railing and grating with adjustments by Ausenco for productivity.

Pricing was sourced from fabricators in Idaho, Montana and Arizona and allowed for the supply, fabrication, shop detailing and painting of bulk steel products graded as light, medium, heavy and extra heavy structural steel designations, and miscellaneous steel including checker plate, grating and handrail.

The structural, mechanical and piping (SMP) contractor will be free-issued the steel for assembly on site.

18.1.9.1.8  Architectural

A buildings list was developed from general arrangement drawings and historical data of similar facilities. Concrete and internal support steel for equipment inside the buildings were accounted for in the engineer’s MTOs.

Pricing for the supply and installation of the building packages was from current quotations and Ausenco’s in-house database from recent relevant projects. Allowances were carried in the estimate for furniture, fittings and fixtures. Overhead cranes were not included in the building costs as they were accounted for in the mechanical equipment list.

18.1.9.1.9  Mechanical Equipment

A detailed mechanical equipment list was developed, generally sized by process and mechanical engineering, and emphasized the selection of proven designs. Quantities were based on process flow diagrams, equipment list, equipment datasheets and general arrangement plans. Mechanical equipment was included in the capital cost estimate in accordance with the latest revision of the equipment list.

Pricing for major process mechanical equipment items was based on budget quotations. Other minor equipment costs were from Ausenco’s in-house database and recent studies or estimated by engineering.

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18.1.9.1.10  Platework

A platework list was prepared for chute work, launders, hoppers, bins and major field erected tanks and silos, this list makes up part of the mechanical equipment list. Platework and liners were quantified in short tons or square feet by engineering. Tanks were designed as panel-style bolted and welded construction. Mechanical bulks quantities were prepared by engineering based on design calculations, previous similar designs, and forced quantity factors. Some minor structures were developed from drawings and sketches.

The basis for the development of installed platework steel was the product of steel material supply and installation costs. Labor-hours were based on local contractors in the region for the installation of the bulk steel plate and rubber or carbon steel lining products with adjustments by Ausenco for productivity.

Pricing was sourced from fabricators in Idaho, Montana and Arizona and allows for the supply, fabrication, shop detailing of platework elements.

Rubber and carbon steel lining products were costed using historical data. Installation hours of rubber liners have been based on increments of 1/4 inches (6 mm Updated) thickness. Installation hours of carbon steel liners were based on increments of 5/8 inches (16 mm) thickness. Tanks identified and designed as panel-style bolted tanks were quoted as supply and install.

The SMP contractor will be free-issued the platework bulk steel for assembly on site.

18.1.9.1.11  Process Plant Piping

The process plant piping was factored from the total installed mechanical. The factor allowed for pipe, fittings, supports, valves, paint, special pipe items and flanges. The piping bulks will be free issued to the SMP contractor for installation.

18.1.9.1.12  Fire Protection and Detection Piping

Fire protection and detection piping was included in the estimate based on a vendor quotation from FSS. The quote allowed for the supply and installation of fire protection/detection equipment, pipes, fittings, supports, valves, special pipe items, and flanges.

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18.1.9.1.13  Water Supply and Distribution

Potable water, fresh water, raw water pipeline, wells and septic water supply and distribution piping were included in the estimate based on a vendor quotation from SPF. The estimate included supply rates for pipe and fittings, civil works and mechanical equipment.

18.1.9.1.14  Pipelines

Ausenco’s scope included the installation of the decant line and tailings distribution lines. The supply rates included pipe and fittings with standard install hours applied to the labor rate. The tailings pipelines will be free issued to the SMP contractor for installation.

18.1.9.1.15  Electrical Equipment

The proposed electrical equipment list aligns with the current mechanical equipment list and load list.

Pricing for major electrical equipment items was developed from a combination of budget quotations for major items and Ausenco’s in-house database.

A 15 kV overhead powerline branching off the main powerline from the mine site was included to feed the process plant, ancillary buildings and tailings area.

18.1.9.1.16  Electrical Bulks

An electrical cable schedule was developed for the Project covering the major power and control cables between electrical equipment (transformers and switchgears/motor control centers or MCCs) and between MCCs and motors. Based on the layout and e-room placement, MTOs for high voltage cables were developed via manual take-offs for major lines and an average length per area was established for medium voltage cables.

Cable trays were estimated via manual take-offs for 6–36-inch trays together with allowances for cable tray covers. While not all cables would travel the full length of the longest tray run, any over-supply is expected to cover costs for risers, bends, covers, fittings and fixtures.

An allowance for terminations, small lighting, and receptacles was developed by factoring from the mechanical equipment supply costs.

18.1.9.1.17  Instrumentation and Control

Instrumentation was developed by factoring from the mechanical equipment supply costs. The process control system for the process plant was priced separately.

18.1.9.1.18  Mobile Equipment

Equipment prices included price ex-factory, freight and erection at site if required.

The major equipment fleet for support to the completion of the site development and bulk earthworks was built up into the earthworks unit rates. Surface mobile equipment to support the construction of the process plant and on-site infrastructure was included in the all-in labor rate provided by the contractors.

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18.1.9.1.19  Freight Costs

Freight costs included inland transportation, export packing, all forwarder costs, ocean freight and air freight where required, insurance, receiving port custom agent fees, and local inland freight to the planned mine site for all bulk materials and process plant equipment.

The estimate freight costs were determined by applying a percentage to the applicable items direct supply cost and then including this cost as a separate value on each line items build-up. Vendor-supplied freight costs were included for major equipment where available.

Vendor packages, third-party costs and any other subcontract and design and construct items were inclusive of any required freight to site

18.1.9.1.20  Import Duties

Import duties were excluded from the estimate.

18.1.9.2  Capitalized Operating cost

A total of $1.7 million of operating costs were included in the initial capital cost estimate, for costs incurred during the pre-production period.

18.1.9.3  Cost Estimate Summary (Processing and Overall Site Infrastructure)

The initial capital cost estimate for process and site infrastructure areas is provided in Table 18-9.

Table 18-9:  Initial Capital Cost Estimate Summary for Process and Site Infrastructure Areas

WBS1		Description		$ M
1400		Mine infrastructure and services			2.0
2100		Bulk earthworks			4.7
2200		Roads			1.1
2300		Surface water management			0.3
3100		Crushing & ore handling			7.2
3200		Grinding & classification			5.4
3300		Gravity separation			0.4
3400		Carbon-in-leach (CIL)			8.0
3500		Carbon elution and goldroom			6.8
3600		Cyanide detox			3.5
3700		Tailings thickening			0.3
3800		Reagents			2.0
3900		Plant building & services			10.0

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WBS1		Description		$ M
4100		Tailings facility & water management			0.2
4200		Tailings & reclaim pipelines			0.5
5100		Power generation & distribution			1.1
5200		Water supply & distribution			6.2
5400		Ancillary buildings			7.2
5500		Surface mobile equipment			2.1
5600		Bulk fuel storage & distribution			0.3
5700		IT and communications			0.3
5800		General			0.3
6100		Main site access road			4.7
6200		Overhead power line			12.2
Direct Subtotal					86.5
7200		Field indirects			2.8
7300		Temporary utilities & services			0.6
7400		Temporary equipment			0.3
7600		Vendors representatives			0.4
7700		Spares & first fills			2.8
7800		Start-up& commissioning			0.6
7900		EPCM and expenses			15.4
Indirect Subtotal					23.0
8100		Provision (contingency)			15.0
N/A		Capitalized Operating cost			1.7
Project Total – Initial Process & On-Site Infrastructure Capital					126.1

Note: totals may not match due to rounding

18.1.10  Tailings Storage and Temporary Waste Rock Storage Facilities Capital Cost Estimate

18.1.10.1  Material Take-off and Bid Solicitation

As discussed in Section 15.5 and presented in Table 15-1, the TSF is designed to be constructed in a total of three primary construction stages (Stages 1 through 3). Stage 1 is separated into two intermediate construction phases (Stages 1A and Stage 1B). In this study, Stage 1A is designated as initial capital and Stage 1B and Stage 2 are denoted as sustaining capital. Stage 3 is currently not required for the FS mine production.

Stage 1A will be the initial stage of construction and provides the basic infrastructure to be able to operate the TSF and TWRSF, including underdrains, embankments, stormwater diversion channels, and a TSF reclaim pond. Stage 1B and Stage 2 will include construction of embankment raises and TSF basin expansions to provide additional tailings storage.

The TSF design, as presented in Section 15.5 is of sufficient detail that construction quantity estimates for major earthwork, geosynthetics, and gravity piping are to an accuracy of 10%. Construction quantities estimates were developed by WSP using Autodesk AutoCAD Civil 3D designs of the TSF and TWRSF facilities and general arrangements and design details.

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Upon WSP receiving and compiling all quotations, the quotations were provided to Paramount and Ausenco for inclusion in the overall capital cost estimate and financial model prepared by Ausenco. For this Report, the preferred general contractor provided an updated capital construction cost estimate to account for design revisions of the TSF and TWRSF as presented in WSP’s 2021 Detailed Design Report, and reflect present unit prices for all construction equipment, labor and materials.

18.1.10.2  Cost Estimate Summary (Tailings Storage and Temporary Waste Rock Storage Facilities)

Ausenco and Paramount incorporated WSP’s preferred contractor’s bid to create a construction cost estimate for Stage 1A, Stage 1B, and Stage 2 to develop the initial and sustaining cost estimates considering the timing required for construction of the TSF expansions as required by the FS mine life. Table 18-10 presents the initial capital cost applied for Stage 1A of the TSF in the economic analysis in Section 19.

Table 18-10: Initial TSF Capital Cost Estimate Summary

WBS		Description		$ M
4100		Tailings Facility & Water Management			12.7
Direct Subtotal					12.7
7000		Indirects			3.0
Indirect Subtotal					3.0
8100		Provision (Contingency)			2.4
Project Total – Initial Tailings Capital					18.1

Note: totals may not match due to rounding.

18.1.11  Indirect Capital Cost Estimate

18.1.11.1  Project Preliminaries (Field Indirects)

Project preliminaries are items or services which are not directly attributable to the construction of specific physical facilities of plant or associated infrastructure but required to be provided as support during the construction period.

These costs may include:

• Temporary construction facilities: site offices, induction center, first aid facilities, admin, portable toilets, temporary fencing, temporary roads and parking.

• Temporary utilities: power supply, temporary grounding and generators, construction lighting, and water supply.

• Construction support: site clean-up and waste disposal, material handling, maintenance of buildings and roads, testing and training, service labor, site transport, site surveys, QA/QC, and security.

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• Construction equipment, tools and supplies purchased by the owner or EPCM contractor: heavy equipment and cranes, large tools, consumables, scaffolding and purchased utilities.

• Material transportation and storage incurred by the Owner or EPCM contractor: all types of freight, agents, staging and marshalling.

• Site office: local services and expenses, communications and office furniture.

Project preliminaries were developed from first principles and summarized in the estimate to cover the construction duration for the process plant and on-site infrastructure. RESPEC and Golder accounted for field indirect costs in their respective discipline areas to support their scope of work.

18.1.11.2  Operational Spares

Mechanical and electrical spares for operations purposes were provided by vendor quotes for major equipment for the initial first year of operations. The remaining equipment was factored using Ausenco’s in-house database.

18.1.11.3  Capital (Insurance) and Commissioning Spares

Major mechanical and electrical spares for capital/insurance and commissioning purposes were provided by vendor quotes for major equipment. The remaining equipment was factored using Ausenco’s in-house database.

18.1.11.4  First Fills

First fills include the costs for the initial construction, first fills for installed equipment and process first fills. First fills were developed by process engineering and separated in the estimate as either construction or commissioning first-fills.

18.1.11.5  Vendors

Costs for vendor representatives for commissioning were identified from the returned budget quotes as a cost per day or an allowance made by engineering. Costs were separated in the estimate as either construction or commissioning vendor representatives.

18.1.11.6  Pre-commissioning, Commissioning

Commissioning assistance from mechanical completion to hand over was developed using Ausenco’s EPCM costs. A modification squad was allowed for in the estimate. The modification squad was carried out to allow the commissioning team to make minor modifications or provide labor assistance for commissioning. The modification squad allowance has been estimated using Ausenco’s in-house database.

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18.1.11.7  Construction Camp and Catering

No onsite camp was allowed for in the estimate. It was assumed that all labor would be sourced from within the region and would reside in either Vale, OR or Boise, ID.

18.1.11.8  EPCM

EPCM services costs covered such items as engineering and procurement services (home office based), construction management services (site based), project office facilities, information technology, staff transfer expenses, secondary consultants, field inspection and expediting, corporate overhead and fees.

The overall EPCM budget for Ausenco’s scope of work was developed from first principles and was inclusive of allocations for other direct costs and general expenses.

18.1.11.9  Cost Estimate Summary (Indirects)

The initial capital cost estimate for indirects provided in Table 18-11.

Table 18-11: Initial Capital Cost Estimate Summary for Indirects

WBS1		Description		$ M
7200		Field indirects			7.9
7300		Temporary utilities & services			0.6
7400		Temporary equipment			0.3
7600		Vendor representatives			0.4
7700		Spares & first fills			2.8
7800		Start-up& commissioning			0.6
7900		EPCM and expenses			15.4
Project Total—Indirects					28.0

Note: totals may not match due to rounding.

18.1.12  Owner’s Costs

The Owner’s initial capital cost estimate is provided in Table 18-12.

Table 18-12:  Initial Owner’s Cost Estimate Summary

Description		$ M
Corporate overheads			0.2
Environmental monitoring			0.3
Site office			0.4
Setup & running costs			0.7
Staff & labor			2.6
Bonding			11.5
Project Total – Initial Owner’s Capital			15.7

Note: totals may not match due to rounding.

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18.1.13  Contingency

18.1.13.1  Estimate Contingency

Estimate contingency was included to address anticipated variances between the specific items contained in the estimate and the final actual project cost.

The estimate contingency does not allow for the following:

• Abnormal weather conditions

• Changes to market conditions affecting the cost of labor or materials

• Changes of scope within the general production and operating parameters

• Effects of industrial disputes.

18.1.13.2  Contingency Analysis

Each of the contributing parties to the estimate provided a contingency value based on their engineering scope and cost development level of definition. These inputs were applied as percentages to their respective base estimates, resulting in a contingency of $19.8 million, or 10% of the total initial project capital cost.

18.1.13.3  Management Reserve Analysis

No management reserve was allowed for.

18.1.13.4  Escalation

No escalation was proportioned to any part of the estimate.

18.1.14  Reclamation and Closure Capital Cost Estimate

Closure costs were provided in Section 17.7 and total approximately $21.1 million over the LOM.

18.2 Operating Cost Estimate

18.2.1  Summary and Basis of Operating Cost Estimate

A summary of the LOM operating costs is provided in Table 18-13.

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Table 18-13: Summary of operating costs over LOM

Cost Category		Unit Costs LOM Average ($ per ton processed)				Total LOM Costs ($ M)
Mining (excl. pre-production)			140.60				332.9
Process			37.72				89.3
G&A			20.65				48.7
Total			198.96				470.9

* Note: totals may not match due to rounding

The basis for the operating cost estimates is included in the discussions provided in the following sub-sections by discipline area. The operating cost estimates have an accuracy range of ±15% per AACE Class 3 estimate guidelines.

18.2.2 Mining Operating Cost Estimate

The mining costs were built up by first principles using the productivity assumptions in Section 13.11 and budgetary quotes. The mining costs were applied in the model to each profile type and ground support type. The mining costs were summarized by year and totaled for the LOM ($332.9 million over the LOM) to determine the total mining costs.

A summary of the mining cost per ton is shown in Table 18-14.

Table 18-14: Summary of Underground Mining Costs per ton

Mine		Yearly (000’s of $/a)				Percentage of Total Cost (%)				Mill Feed ($/ton)
Drilling			17,093				5	%			7.25
Blasting			15,125				5	%			6.42
Mucking			6,593				2	%			2.80
Bolting			34,974				11	%			14.83
Shotcrete Spray			6,250				2	%			2.65
Shotcrete Transmixer			904				0	%			0.38
Haulage			6,543				2	%			2.78
Backfill			64,550				19	%			27.38
Subtotal mining operating cost			152,034				46	%			64.48
Labor cost operating			129,293				39	%			54.84
Electrical cost operating			10,951				3	%			4.64
Diesel fuel cost operating			7,602				2	%			3.22
General supplies/Indirect operating			2,999				1	%			1.27
Contingency			29,988				9	%			12.72
Subtotal general operating cost			180,832				54	%			76.70
Total (mining + general)			332,865				100	%			141.18

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Excluding mining costs from the pre-production period (accounted for in the initial capital cost) results in an average mining cost of $140.60/ton processed over the LOM.

18.2.2.1  Underground Labor

Staffing was estimated by benchmarking against similar projects. The labor costs incorporated requirements for underground operations such as operating underground equipment, technical support, underground electricians, underground mechanics, and underground management. A summary of the underground labor required is included as Table 18-15.

Table 18-15:  Underground Labor Summary

Position		Labor Code				No. of Employees				Total Cost per Year ($’000/a)
Technical Service Engineer			Salary				1				226.2
Mine engineer			Salary				1				187.9
Mine surveyor			Salary				2				341.9
Mine geologist			Salary				2				325.1
Mine superintendent			Salary				1				226.2
Mine clerk			Hourly				1				74.3
Mine foreman			Salary				4				916.7
Underground miner			Hourly				33				5,802.1
Underground laborer			Hourly				25				2,483.3
Mine electricians			Hourly				2				401.1
Mine maintenance superintendent			Salary				1				251.1
Heavy equipment elec-mechanic			Hourly				10				2,097.2
Welder			Hourly				2				339.8
Serviceman			Hourly				2				270.8
Maintenance laborer			Hourly				2				270.8
Light vehicle mechanic			Hourly				1				129.0
Total Underground Personnel							83				3,759.9

The quantities shown in Table 18-15 do not include milling process personnel nor site management/general & administrative staff. The total underground mine personnel required will be 83 workers. The shift system for administrative personnel is planned to be four days on and three days off, at 10 hours per day. Production-related mining personnel (operators, fitters, electricians, and assistants) will work a shift system of four days on and three days off in two crews. Each crew will provide 12 hour/day coverage so that the mine can operate 24 hours/day, four days per week. Some personnel may work additional overtime through weekends for backfill, dewatering, and care-and-maintenance requirements, as needed. The operating calendar is based on 360 operating days per year. The planned mine organization chart is shown in Figure 18-1.

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Figure 18-1: Proposed Mine Organizational Chart

Source: MDA(RESPEC), 2022.

18.2.2.2  Other Underground Costs

Power costs were estimated using consumptions from the equipment manufacturer and the cost of power. A unit power cost of $0.0584 per kWh was used, based on a December 2025 power rate schedule from Idaho Power.

Diesel costs were estimated using consumptions from InfoMine cost models, equipment specifications, vendor information, and the cost of local diesel. The unit cost of diesel used for this study is $2.51/gallon.

General supplies were estimated using 1.0% of the total underground operating costs. The total cost of general supplies is $1.27/ore ton. The general supplies included mining software, engineering supplies, geology supplies, survey supplies, and other general supplies.

18.2.3 Process Operating Cost Estimate

The process operating cost is estimated at $89.3 million over the LOM, or an average of $37.72/ton processed over the LOM. A breakdown of these costs is presented in Table 18-16.

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Table 18-16: Average Annual Process Operating Cost

Cost Center		Annual Costs* ($’000/a)		Percentage of Total (%)		Unit Costs LOM Average ($ per ton processed)
Reagents & Operating Consumables		3,277		33		12.46
Power		1,292		13		4.91
General Maintenance		791		8		3.01
Mobile Equipment		156		2		0.59
Labor		4,404		44		16.75
Total		9,919		100		37.72

*Note: totals may not match due to rounding

18.2.3.1 Reagents and Operating Consumables

Individual reagent consumption rates were estimated based on the metallurgical testwork results, Ausenco’s in-house database and experience, industry practice and peer-reviewed literature. Reagent costs were obtained through vendor quotes or benchmarking for similar projects performed by Ausenco.

Other consumables (e.g., liners for the primary crusher, ball mill and ball media for the mills) were estimated using:

• Metallurgical testing results (abrasion index)

• Vendor inputs and recommendations

• Ausenco’s in-house calculation methods, including simulations

• Forecast nominal power consumption.

Reagents and consumables represent 33% of the total process operating cost at an average of $12.46/ton of plant feed over the LOM.

18.2.3.2 Fuel and Utilities

A unit power cost of $0.0584/kWh was used, based on a December 2025 power rate schedule from Idaho Power. Carson Fuel provided an all-in contract price for diesel based on annual forecast usage for the Project at $2.51/gal, which was used for the Study.

The processing power draw was based on the average power utilization of each motor on the electrical load list for the process plant and services. Power will be supplied by the Idaho Power Company to service the facilities at the site. The total average process plant power cost is $4.91/ton over the LOM, or 13% of the total process operating cost.

18.2.3.3 Maintenance

General maintenance costs are 8% of the total operating cost at $3.01/ton over the LOM. Annual maintenance consumable costs were calculated based on a total installed mechanical capital cost by area using a weighted average factor from 1–5%. The factor was applied to the cost of the installed mechanical equipment.

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18.2.3.4 Mobile Equipment

Vehicle costs were based on a scheduled number of light vehicles and mobile equipment, including fuel, maintenance, spares and tires, and annual registration and insurance fees. This corresponds to an average of $0.59/ton over the LOM.

18.2.3.5 Labor

Staffing numbers and positions were estimated based on other similar projects and Ausenco references. The labor costs incorporate requirements for plant operation, such as management, metallurgy, operations, maintenance and assay laboratory, and contractor allowance. The total operational labor is 38 employees, averaging 21 employees per shift.

Individual personnel were divided into their respective positions and classified as either 10-hour or 12-hour shift employees. Salaries were determined using published U.S. labor market data and were also used to develop the total G&A labor cost. The rates were estimated as overall rates, including all burden costs.

Table 18-17: Process Plant Labor

Position		Labor Code		No. of Employees
Processing Superintendent		Salary		1
Gold Room Operator		Hourly		1
Reagents/TMF Operator		Hourly		1
Shift Foreman/Crusher Operator		Hourly		4
Control Room Operator/Mill Operator		Hourly		4
CIL Operator/Elution Operator		Hourly		4
CN Destruction Operator		Hourly		4
Plant Metallurgist		Salary		1
Chief Assayer		Hourly		1
Assayer		Hourly		1
Sample Bucker		Hourly		2
Maintenance Foreman		Salary		1
Mill Wright/Fitter (crew)		Hourly		2
Service Man		Hourly		2
Electrical Foreman		Hourly		1
Contract Electrician		Hourly		1
Trades Assistant		Hourly		4
Electrician		Hourly		1
Mill Wright/Fitter (shift)		Hourly		1
Instrument Tech		Hourly		1
Total				38

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Labor costs represent 44% of the total process operating cost at an average of $16.75/ton of plant feed over the LOM.

18.2.4 General and Administrative Operating Cost Estimate

A bottoms-up approach was used to develop estimates for G&A costs at $5.4M/a, or $48.7 million over the LOM, representing an average of $20.65/ton processed over the LOM.

The G&A labor costs were estimated by developing a headcount profile for each department that was then forecast over the LOM. Labor rates were determined based on published U.S. labor market data and were applied to develop the total G&A labor cost.

Health and safety equipment, supplies, training, and environmental costs were provided by Paramount Gold, as were the information technology and telecommunications costs for telecommunication, networking, internet, computers, radio system and repairs.

A breakdown summary of forecast LOM G&A costs is shown in Table 18-18.

Table 18-18: Annual Average G&A Operating Cost Summary

Cost Center		Annual Cost* ($000’s/a)		% of total		Unit Cost LOM Average ($/ton processed)
G&A maintenance		100.0		2		0.38
Personnel (incl. bonuses and benefits)		3,093		58		11.90
Human resources and public relations		231.4		4		0.89
Power		15.0		0.3		0.06
Laboratory		86.4		2		0.33
Miscellaneous, supplies & equipment		151.0		3		0.58
Fees and consulting services		946.4		18		3.64
G&A vehicles & transportation		80.1		1		0.31
Environmental		15.3		0.3		0.06
IT & telecommunications		60.0		1		0.23
Contract services		479.9		9		1.85
Mine software		45.4		1		0.17
Mine hardware		61.3		1		0.24
Total		5,365		100		20.65

* For a typical operating year.

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19 ECONOMIC ANALYSIS

19.1 Forward-Looking Information

Paramount is subject to the reporting requirements of the Exchange Act and this filing and other U.S. reporting requirements are governed by Subpart 1300 of Regulation S-K promulgated by the Securities and Exchange Commission (SEC). The results of the economic analyses discussed in this section represent forward-looking statements within the meaning of applicable securities laws relating to Paramount Gold Nevada Corp. These statements by their nature involve substantial risks and uncertainties. Statements involving the foregoing results of economic analysis are forward-looking statements. Without limiting the generality of the foregoing, words such as “may”, “anticipate”, “intend”, “could”, “estimate”, or “continue” or the negative or other comparable terminology are intended to identify forward-looking statements. Should one or more of these risks or uncertainties materialize or should the underlying assumptions prove incorrect, actual outcomes and results could differ materially from those indicated in the forward-looking statements.

Information that is forward-looking includes, but is not limited to, the following:

• Proven and Probable Mineral Reserve estimates which have been modified from Measured and Indicated Mineral Resource estimates

• Assumed commodity prices and exchange rates

• Proposed mine production plan

• Projected mining and process recovery rates

• Assumptions as to mining dilution and estimated future production

• Assumptions as geotechnical support requirements for underground openings

• Proposed sustaining costs and operating costs

• Seabridge Gold’s intentions to convert the NPI royalty into Paramount equity upon Paramount securing sufficient construction financing

• Assumptions as to closure costs and closure requirements

• Assumptions as to environmental, permitting, and social risks.

Additional risks to the forward-looking information include:

• Changes to costs of production from what is assumed

• Unexpected variations in quantity of mineralized material, grade or recovery rates

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 292 May 27, 2026

• Geotechnical or hydrogeological considerations during mining being different from what was assumed

• Failure of mining methods to operate as anticipated

• Failure of plant, equipment or processes to operate as anticipated

• Changes to assumptions as to the availability of electrical power, and the power rates used in the operating cost estimates and financial analysis

• Unrecognized environmental risks

• Unanticipated reclamation expenses

• Ability to maintain the social license to operate

• Accidents, labor disputes and other risks of the mining industry

• Changes to interest rates

• Changes to applicable tax rates.

Calendar years used in the financial analysis are provided for conceptual purposes only. Additional permits still must be obtained in support of operations; and approval to proceed is still required from Paramount’s Board of Directors.

19.2 Methodology Used

The Project has been evaluated using a discounted cashflow (DCF) analysis based on a 5% discount rate. Cash inflows consist of annual revenue projections. Cash outflows consist of capital expenditures, operating costs, taxes, and royalties. These are subtracted from the inflows to arrive at the annual cash flow projections. Cash flows are taken to occur at the midpoint of each period. Tax calculations involve complex variables that can only be accurately determined during operations and, as such, the actual post-tax results may differ from those estimated. A sensitivity analysis was performed to assess the impact of variations in metal prices, discount rate, head grade, recovery, total operating cost, and total capital costs.

An economic model was developed to estimate annual pre-tax and post-tax cash flows and sensitivities of the Project based on a 5% discount rate. Tax estimates involve complex variables that can only be accurately calculated during operations and, as such, the post-tax results are approximations.

The capital and operating cost estimates developed specifically for this Project are presented in Section 18 using second quarter (Q2) 2026 US dollars. The economic analysis was run on a constant dollar basis with no inflation.

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19.3 Financial Model Parameters

The economic analysis contemplated in the FS uses metal prices that remain constant over the Project life and are based on the assessment outlined in Section 16 at $3,600/oz gold and $48.00/oz silver prices. No price inflation or escalation factors were utilized as commodity prices can be volatile, and there is the potential for deviation from the forecast. Exchange rates used in the Report are detailed in Section 18.1.6.

The economic analysis was performed using the following assumptions:

• Construction period of 18 months

• All construction and operating costs prior to achieving commercial operation are capitalized

• Mine life of 9.3 years

• Cost estimates in constant Q2 2026 US dollars with no inflation or escalation

• Capital costs funded with 100% equity (no financing costs assumed)

• All cash flows discounted at a 5% discount rate to the start of construction

• Metal is assumed to be sold in the same year it is produced

• No contractual arrangements for refining or offtake are in place.

19.4 Taxes

The Project was evaluated on a post-tax basis to provide an approximate value of the potential economics. The tax model was prepared by MNP LLP, an independent tax consultant. The calculations are based on the tax regime as of the date of the FS, and include estimates for Paramount’s expenditures, and related impacts to various tax pool balances, between the FS and the assumed construction start date.

At the Report effective date, the Project was assumed to be subject to the following tax regime:

• US Federal corporate income tax system of a 21% tax rate;

• Oregon tax rate of 7.6% for net proceeds of more than $1 million;

• Total undiscounted tax payments are estimated to be $117.2 million over the LOM.

19.5 Ro yalty

A 1.5% net smelter revenue (NSR) royalty was assumed, resulting in approximately $21.1 million in undiscounted royalty payments over the LOM. The FS assumes that Seabridge will convert its 10% NPI royalty into Paramount equity upon Paramount securing sufficient construction financing, and thus the NPI was not included in the financial model.

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19.6 Economic Analysis

The economic analysis was performed assuming a 5% discount rate.

The pre-tax net present value (NPV) discounted at 5% is $458.9 M; the IRR is 42.8%; and payback period is 2.1 years.

On a post-tax basis, the NPV discounted at 5% is $374.7 M; the IRR is 38.9 %; and the payback period is 2.2 years.

A summary of forecast Project economics is shown graphically in Figure 19-1 and listed in Table 19-1.

A cashflow on an annualized basis is provided in Table 19-2.

Figure 19-1: Forecast Project Post-Tax Unlevered, Undiscounted Free Cash Flow ($ M)

Source: Ausenco 2026

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 295 May 27, 2026

Table 19-1: Summary of Forecast Project Economics

Area		Item		Units		LOM Total/Avg.
General		Gold price		$/oz		3,600
		Silver price		$/oz		48.00
		Mine life		years		9.3
		Total mill feed tons		tons x 1,000		2,358
Production (gold)		Mill head grade Au		oz/ton		0.18
		Mill recovery rate Au		%		92.6
		Total mill ounces recovered Au		oz x 1,000		385.8
		Total average annual production Au		oz x 1,000		41.4
Production (silver)		Mill head grade Ag		oz/ton		0.28
		Mill recovery rate Ag		%		73.5
		Total mill ounces recovered Ag		oz x 1,000		480.1
		Total average annual production Ag		oz x 1,000		51.5
Operating Costs		Mining cost		$/ton processed		140.60
		Processing cost		$/ton processed		37.72
		G&A cost		$/ton processed		20.65
		Total operating costs		$/ton processed		198.96
		Refining cost Au		$/oz		5.00
		Refining cost Ag		$/oz		0.50
		*Cash costs net of by-products		$/oz Au		1,217.95
		**AISC net of by-products		$/oz Au		1,441.57
Capital Costs		Initial capital		$M		189.8
		Sustaining capital		$M		65.1
		Closure costs		$M		21.1
Financials(pre-tax)		Gross Revenue		$M		1,410.6
		Pre-tax unlevered free cash flow		$M		658.0
		Pre-tax NPV, 5%		$M		458.9
		Pre-tax IRR%		%		42.8
		Pre-tax Payback		years		2.1
Financials(post-tax)		Post-tax unlevered free cash flow		$M		540.7
		Post-tax NPV, 5%		$M		374.7
		Post-tax IRR%				38.9
		Post-tax Payback		years		2.2

Notes:

* Cash costs consist of mining costs, processing costs, G&A and refining charges and royalties.

** All-in sustaining costs (AISC) includes cash costs plus sustaining capital and closure costs. AISC is at the Project-level and does not include an estimate of corporate G&A.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 296 May 27, 2026

Table 19-2: Project Cashflow on an Annualized Basis

Dollar figures in Real 2026 $ M unless otherwise noted
Macro Assumptions		Units		Total/ Avg.		Y -2		Y -1		Y 1		Y 2		Y 3		Y 4		Y 5		Y 6		Y 7		Y 8		Y 9		Y 10
Gold Price		$/oz		3,600		3,600		3,600		3,600		3,600		3,600		3,600		3,600		3,600		3,600		3,600		3,600		3,600
Silver Price		$/oz		48.00		48.00		48.00		48.00		48.00		48.00		48.00		48.00		48.00		48.00		48.00		48.00		48.00
Revenue		$M		1,410.6		–		2.9		124.1		186.3		167.7		179.9		174.0		168.5		160.4		113.2		126.7		6.9
Operating Cost		$M		(469.1)		–		–		(44.8)		(54.3)		(53.4)		(51.9)		(52.9)		(50.7)		(55.9)		(49.7)		(47.8)		(7.7)
Refining Charges		$M		(2.2)		–		(0.0)		(0.2)		(0.3)		(0.3)		(0.3)		(0.3)		(0.3)		(0.3)		(0.2)		(0.2)		(0.0)
Royalties		$M		(21.1)		–		(0.0)		(1.9)		(2.8)		(2.5)		(2.7)		(2.6)		(2.5)		(2.4)		(1.7)		(1.9)		(0.1)
EBITDA		$M		918.2		–		2.9		77.2		129.0		111.6		125.0		118.3		115.0		101.9		61.6		76.7		(0.9)
Initial Capex		$M		(189.8)		(55.4)		(134.4)		–		–		–		–		–		–		–		–		–		–
Sustaining Capex		$M		(65.1)		–		–		(24.4)		(10.7)		(8.3)		(11.9)		(7.2)		(1.2)		(0.4)		(0.4)		(0.4)		–
Closure Capex		$M		(21.1)		–		–		–		–		–		–		–		–		–		–		–		(21.1)
Salvage Value		$M		15.8		–		–		–		–		–		–		–		–		–		–		–		15.8
Pre-Tax Unlevered Free Cash Flow		$M		658.0		(55.4)		(131.6)		52.8		118.2		103.2		113.1		111.0		113.8		101.4		61.1		76.3		(6.2)
Corporate Income Tax		$M		(117.2)		–		–		(2.0)		(4.5)		(3.9)		(18.4)		(20.9)		(22.6)		(19.5)		(10.9)		(14.5)		–
Post-Tax Unlevered Free Cash Flow		$M		540.7		(55.4)		(131.6)		50.8		113.7		99.3		94.8		90.1		91.2		81.9		50.2		61.7		(6.2)
Production Summary
Total Resource Mined		kt		2,357.8		–		5.2		226.3		287.4		272.0		284.1		265.2		240.4		298.0		233.6		226.9		18.8
Mill Head Grade (Au)		oz/t		0.18		–		0.17		0.16		0.19		0.18		0.19		0.19		0.21		0.16		0.14		0.16		0.11
Mill Head Grade (Ag)		oz/t		0.28		–		0.25		0.25		0.27		0.25		0.28		0.28		0.26		0.31		0.29		0.30		0.23
Mill Recovery (Au)		%		92.6		–		92.4		92.3		92.9		92.7		92.8		92.9		93.1		92.2		91.8		92.4		90.5
Mill Recovery (Ag)		%		73.5		–		72.2		71.6		73.4		72.2		73.8		73.6		72.6		74.9		74.2		74.6		70.8
Recovered Gold		koz		385.8		–		0.8		34.0		51.0		46.0		49.2		47.7		46.2		43.7		30.8		34.5		1.9
Recovered Silver		koz		480.1		–		0.9		39.9		57.8		50.0		59.4		54.3		45.6		68.0		50.5		50.5		3.1
Payable Gold		koz		385.5		–		0.8		33.9		51.0		45.9		49.2		47.6		46.2		43.7		30.8		34.5		1.9
Payable Silver		koz		477.7		–		0.9		39.7		57.6		49.7		59.1		54.0		45.4		67.7		50.3		50.3		3.1
Gold Revenue		$M		1,387.6		–		2.9		122.2		183.5		165.3		177.1		171.4		166.3		157.1		110.7		124.2		6.8
Silver Revenue		$M		22.9		–		0.0		1.9		2.8		2.4		2.8		2.6		2.2		3.3		2.4		2.4		0.1
Total Revenue		$M		1,410.6		–		2.9		124.1		186.3		167.7		179.9		174.0		168.5		160.4		113.2		126.7		6.9
Royalties		$M		21.1		–		(0.0)		(1.9)		(2.8)		(2.5)		(2.7)		(2.6)		(2.5)		(2.4)		(1.7)		(1.9)		(0.1)
Total Offsite Charges		$M		(2.2)		–		(0.0)		(0.2)		(0.3)		(0.3)		(0.3)		(0.3)		(0.3)		(0.3)		(0.2)		(0.2)		(0.0)
Total Operating Costs		$M		(469.1)		–		–		(44.8)		(54.3)		(53.4)		(51.9)		(52.9)		(50.7)		(55.9)		(49.7)		(47.8)		(7.7)
Mine Operating Costs		$M		(332.9)		–		(1.4)		(30.2)		(38.6)		(38.0)		(36.3)		(37.6)		(35.8)		(40.1)		(35.0)		(33.2)		(6.6)
Mill Processing		$M		(89.3)		–		(0.3)		(9.2)		(10.3)		(10.0)		(10.2)		(9.9)		(9.5)		(10.5)		(9.4)		(9.2)		(0.7)
G&A Costs		$M		(48.7)		–		–		(5.4)		(5.4)		(5.4)		(5.4)		(5.4)		(5.4)		(5.4)		(5.4)		(5.4)		(0.4)
Capitalized Operating Cost Transfer		$M		1.7		–		1.7		–		–		–		–		–		–		–		–		–		–
Total Initial Capital		$M		(189.8)		(55.4)		(134.4)		–		–		–		–		–		–		–		–		–		–
Capitalized Processing Operating cost		$M		(1.7)		–		(1.7)		–		–		–		–		–		–		–		–		–		–
1000—Mining		$M		(31.9)		(0.7)		(31.2)		–		–		–		–		–		–		–		–		–		–
2000—Site Development		$M		(6.2)		(2.2)		(4.0)		–		–		–		–		–		–		–		–		–		–
3000 – Min. Processing		$M		(43.5)		(15.2)		(28.2)		–		–		–		–		–		–		–		–		–		–
4000 – Tail/Waste Mgmt		$M		(13.4)		(4.7)		(8.7)		–		–		–		–		–		–		–		–		–		–
5000—Onsite Infra.		$M		(17.4)		(6.1)		(11.3)		–		–		–		–		–		–		–		–		–		–
6000—Off-Site Infra.		$M		(16.9)		(5.9)		(11.0)		–		–		–		–		–		–		–		–		–		–
7000—Indirects		$M		(26.0)		(9.1)		(16.9)		–		–		–		–		–		–		–		–		–		–
8000—Provisions		$M		(17.3)		(6.1)		(11.3)		–		–		–		–		–		–		–		–		–		–
9000—Owner Costs		$M		(15.7)		(5.5)		(10.2)		–		–		–		–		–		–		–		–		–		–
Total Sustaining Capital		$M		(65.1)		–		–		(24.4)		(10.7)		(8.3)		(11.9)		(7.2)		(1.2)		(0.4)		(0.4)		(0.4)		–
1000—Mining		$M		(40.8)		–		–		(22.4)		(7.2)		(4.0)		(3.6)		(2.9)		(0.8)		–		–		–		–

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 297 May 27, 2026

Dollar figures in Real 2026 $ M unless otherwise noted

Macro Assumptions

Units

Total/Avg.

Y -2

Y -1

Y 1

Y 2

Y 3

Y 4

Y 5

Y 6

Y 7

Y 8

Y 9

Y 10

2000—Site Development

$M

–

–

–

–

–

–

–

–

–

–

–

–

–

3000 – Min. Processing

$M

(3.9)

–

–

(0.4)

(0.4)

(0.4)

(0.4)

(0.4)

(0.4)

(0.4)

(0.4)

(0.4)

–

4000 – Tailings/Waste Mgmt

$M

(20.4)

–

–

(1.6)

(3.1)

(3.9)

(7.9)

(3.9)

–

–

–

–

–

5000—Onsite Infra.

$M

–

–

–

–

–

–

–

–

–

–

–

–

–

6000—Off-Site Infra.

$M

–

–

–

–

–

–

–

–

–

–

–

–

–

7000—Indirects

$M

–

–

–

–

–

–

–

–

–

–

–

–

–

8000—Provisions

$M

–

–

–

–

–

–

–

–

–

–

–

–

–

9000—Owner Costs

$M

–

–

–

–

–

–

–

–

–

–

–

–

–

Total Capital Expenditures Including Salvage Value

$M

(260.2)

(55.4)

(134.4)

(24.4)

(10.7)

(8.3)

(11.9)

(7.2)

(1.2)

(0.4)

(0.4)

(0.4)

(5.3)

Notes:

All dollar figures are in Real 2026 million USD unless otherwise noted.

† Yearly cashflow figures for closure costs extend to 20+ years beyond end of mine life and are not shown above; the total closure cost listed reflects the accurate closure costs over the LOM.

* Cash costs consist of mining costs, processing costs, mine-level G&A and refining charges and royalties.

** AISC includes cash costs plus sustaining capital and closure costs.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 298 May 27, 2026

19.7 Sensitivity Analysis

A sensitivity analysis was conducted on the base case pre-tax and post-tax NPV and IRR, using the following variables: commodity prices, mill head grades, initial capital cost, operating cost, metallurgical recovery, and discount rate.

Figure 19-2 shows the summary pre-tax sensitivity, and Figure 19-3 shows the post-tax sensitivity results, with detailed sensitivity tables presented in Table 19-3 and Table 19-4.

Figure 19-2: Pre-Tax NPV & IRR Sensitivity Results

Source: Ausenco, 2026.

Figure 19-3: Post-Tax NPV & IRR Sensitivity Results

Source: Ausenco, 2026.

The analysis showed that the Project is most sensitive to metal price, head grade, metallurgical recovery rates, and initial capital cost, and less sensitive to operating cost.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 299 May 27, 2026

Table 19-3: Summary Pre-Tax Sensitivity Analysis

Pre-Tax Sensitivity to Metal Price
		Pre-Tax NPV5% (US$M)Sensitivity to Discount Rate																																		Pre-Tax IRR (%) Sensitivity to Discount Rate
		Commodity Price																																		Commodity Price
Discount Rate							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Discount Rate							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			1.0	%			218.4				349.5				480.6				611.8				742.9				874.0				1,005						1.0	%			19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			3.0	%			177.9				295.1				412.3				529.5				646.8				764.0				881.2						3.0	%			19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			5.0	%			143.1				248.4				353.7				458.9				564.2				669.4				774.7						5.0	%			19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			8.0	%			99.9				190.2				280.4				370.7				460.9				551.2				641.4						8.0	%			19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			10.0	%			76.0				157.8				239.7				321.5				403.4				485.2				567.1						10.0	%			19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			Pre-Tax NPV5% (US$M) Sensitivity to OPERATING COST																																		Pre-Tax IRR(%)Sensitivity to OPERATING COST
			Commodity Price																																		Commodity Price
Total OPERATING COST							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Total OPERATING COST							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			213.4				318.7				423.9				529.2				634.4				739.7				844.9						(20	%)			24.9	%			32.9	%			40.3	%			47.2	%			53.8	%			60.1	%			66.3	%
			(10	%)			178.3				283.5				388.8				494.0				599.3				704.6				809.8						(10	%)			22.1	%			30.4	%			37.9	%			45.0	%			51.7	%			58.1	%			64.3	%
			—				143.1				248.4				353.7				458.9				564.2				669.4				774.7						—				19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			10	%			108.0				213.3				318.5				423.8				529.0				634.3				739.5						10	%			16.1	%			25.1	%			33.1	%			40.5	%			47.4	%			54.0	%			60.3	%
			20	%			72.9				178.1				283.4				388.6				493.9				599.2				704.4						20	%			12.9	%			22.3	%			30.6	%			38.2	%			45.2	%			51.9	%			58.3	%
			Pre-Tax NPV5% (US$M) Sensitivity to Initial CAPEX																																		Pre-Tax IRR(%)Sensitivity to Initial CAPEX
			Commodity Price																																		Commodity Price
Initial CAPEX							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Initial CAPEX							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			179.7				285.0				390.2				495.5				600.7				706.0				811.3						(20	%)			25.8	%			35.5	%			44.3	%			52.6	%			60.5	%			68.0	%			75.3	%
			(10	%)			161.4				266.7				371.9				477.2				582.5				687.7				793.0						(10	%)			22.2	%			31.3	%			39.6	%			47.3	%			54.5	%			61.5	%			68.2	%
			—				143.1				248.4				353.7				458.9				564.2				669.4				774.7						—				19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			10	%			124.8				230.1				335.4				440.6				545.9				651.1				756.4						10	%			16.6	%			24.8	%			32.1	%			38.9	%			45.3	%			51.5	%			57.3	%
			20	%			106.6				211.8				317.1				422.3				527.6				632.8				738.1						20	%			14.3	%			22.1	%			29.1	%			35.6	%			41.7	%			47.5	%			53.0	%
			Pre-Tax NPV5% (US$M) Sensitivity to Mill Recovery																																		Pre-Tax IRR(%)Sensitivity to Mill Recovery
			Commodity Price																																		Commodity Price
Mill Recovery							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Mill Recovery							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			(9.9	)			73.5				156.8				240.2				323.5				406.9				490.2						(20	%)			3.8	%			12.8	%			20.4	%			27.2	%			33.4	%			39.3	%			44.8	%
			(10	%)			66.6				161.0				255.3				349.6				443.9				538.2				632.5						(10	%)			12.1	%			20.7	%			28.3	%			35.3	%			41.8	%			47.9	%			53.8	%
			—				143.1				248.4				353.7				458.9				564.2				669.4				774.7						—				19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			10	%			219.6				335.8				452.0				568.3				684.5				800.7				916.9						10	%			25.5	%			34.3	%			42.3	%			49.8	%			57.0	%			63.8	%			70.5	%
			20	%			296.1				423.3				550.5				677.6				804.8				931.9				1,059						20	%			31.4	%			40.4	%			48.7	%			56.6	%			64.1	%			71.3	%			78.3	%
			Pre-Tax NPV5% (US$M) Sensitivity to Head Grade																																		Pre-Tax IRR(%)Sensitivity to Head Grade
			Commodity Price																																		Commodity Price
Head Grade							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Head Grade							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			(3.9	)			80.3				164.5				248.7				332.9				417.1				501.3						(20	%)			4.5	%			13.5	%			21.0	%			27.8	%			34.1	%			40.0	%			45.5	%
			(10	%)			69.6				164.4				259.1				353.8				448.5				543.3				638.0						(10	%)			12.4	%			21.0	%			28.6	%			35.6	%			42.1	%			48.2	%			54.2	%
			—				143.1				248.4				353.7				458.9				564.2				669.4				774.7						—				19.2	%			27.8	%			35.5	%			42.8	%			49.6	%			56.1	%			62.3	%
			10	%			201.9				315.5				429.2				542.9				656.5				770.2				883.9						10	%			24.1	%			32.8	%			40.7	%			48.2	%			55.3	%			62.0	%			68.6	%
			20	%			203.1				316.9				430.7				544.6				658.4				772.2				886.1						20	%			24.2	%			32.9	%			40.8	%			48.3	%			55.4	%			62.1	%			68.7	%

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 300 May 27, 2026

Table 19-4: Summary Post-Tax Sensitivity Analysis

Post-Tax Sensitivity to Metal Price
		Post-Tax NPV5% (US$M)Sensitivity to Discount Rate																																		Post-Tax IRR (%) Sensitivity to Discount Rate
		Commodity Price																																		Commodity Price
Discount Rate							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Discount Rate							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			1.0	%			195.8				298.6				400.8				502.3				603.5				704.7				805.9						1.0	%			17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			3.0	%			158.2				250.9				342.6				433.7				524.5				615.1				705.6						3.0	%			17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			5.0	%			125.9				209.8				292.7				374.7				456.5				537.9				619.4						5.0	%			17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			8.0	%			85.7				158.5				230.1				300.9				371.3				441.3				511.3						8.0	%			17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			10.0	%			63.4				129.9				195.2				259.6				323.7				387.3				450.9						10.0	%			17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			Post-Tax NPV5% (US$M) Sensitivity to OPERATING COST																																		Post-Tax IRR(%)Sensitivity to OPERATING COST
			Commodity Price																																		Commodity Price
Total OPERATING COST							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Total OPERATING COST							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			180.1				263.0				345.0				426.8				508.3				589.7				671.1						(20	%)			22.8	%			29.9	%			36.5	%			42.7	%			48.5	%			54.1	%			59.5	%
			(10	%)			153.1				236.5				318.9				400.8				482.4				563.8				645.2						(10	%)			20.4	%			27.8	%			34.5	%			40.8	%			46.7	%			52.4	%			57.9	%
			—				125.9				209.8				292.7				374.7				456.5				537.9				619.4						—				17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			10	%			97.8				183.0				266.2				348.6				430.5				512.0				593.5						10	%			15.2	%			23.2	%			30.3	%			36.9	%			43.1	%			48.9	%			54.5	%
			20	%			65.1				155.7				239.5				322.3				404.5				486.1				567.6						20	%			12.1	%			20.8	%			28.1	%			34.9	%			41.2	%			47.1	%			52.8	%
			Post-Tax NPV5% (US$M) Sensitivity to Initial CAPEX																																		Post-Tax IRR(%)Sensitivity to Initial CAPEX
			Commodity Price																																		Commodity Price
Initial CAPEX							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Initial CAPEX							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			162.5				246.4				329.2				411.3				493.0				574.5				655.9						(20	%)			24.4	%			33.1	%			41.1	%			48.6	%			55.6	%			62.3	%			68.7	%
			(10	%)			144.2				228.1				310.9				393.0				474.7				556.2				637.6						(10	%)			20.9	%			29.0	%			36.4	%			43.3	%			49.8	%			56.0	%			61.9	%
			—				125.9				209.8				292.7				374.7				456.5				537.9				619.4						—				17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			10	%			107.6				191.5				274.4				356.5				438.2				519.6				601.1						10	%			15.3	%			22.5	%			29.0	%			35.1	%			40.8	%			46.2	%			51.3	%
			20	%			89.4				173.2				256.1				338.2				419.9				501.4				582.8						20	%			13.1	%			19.9	%			26.1	%			31.8	%			37.2	%			42.3	%			47.2	%
			Post-Tax NPV5% (US$M) Sensitivity to Mill Recovery																																		Post-Tax IRR(%)Sensitivity to Mill Recovery
			Commodity Price																																		Commodity Price
Mill Recovery							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Mill Recovery							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			(14.7	)			65.5				136.9				203.3				269.0				334.2				399.1						(20	%)			3.2	%			12.0	%			19.0	%			25.0	%			30.5	%			35.7	%			40.7	%
			(10	%)			59.0				140.2				215.2				289.4				363.0				436.3				509.3						(10	%)			11.4	%			19.3	%			26.0	%			32.2	%			38.0	%			43.5	%			48.7	%
			—				125.9				209.8				292.7				374.7				456.5				537.9				619.4						—				17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			10	%			187.1				278.7				369.4				459.6				549.6				639.5				729.3						10	%			23.5	%			31.3	%			38.5	%			45.2	%			51.5	%			57.5	%			63.3	%
			20	%			247.5				347.0				445.9				544.3				642.7				740.9				839.1						20	%			28.7	%			36.7	%			44.2	%			51.1	%			57.7	%			64.0	%			70.0	%
			Post-Tax NPV5% (US$M) Sensitivity to Head Grade																																		Post-Tax IRR(%)Sensitivity to Head Grade
			Commodity Price																																		Commodity Price
Head Grade							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%		Head Grade							(30	%)			(20	%)			(10	%)			—				10	%			20	%			30	%
			(20	%)			(8.9	)			72.1				143.1				210.0				276.4				342.2				407.8						(20	%)			3.9	%			12.7	%			19.5	%			25.5	%			31.1	%			36.4	%			41.4	%
			(10	%)			61.8				142.9				218.2				292.8				366.7				440.3				513.6						(10	%)			11.7	%			19.5	%			26.2	%			32.4	%			38.3	%			43.8	%			49.0	%
			—				125.9				209.8				292.7				374.7				456.5				537.9				619.4						—				17.9	%			25.5	%			32.4	%			38.9	%			44.9	%			50.7	%			56.2	%
			10	%			173.0				262.8				351.6				440.0				528.0				615.9				703.8						10	%			22.2	%			30.0	%			37.1	%			43.7	%			49.9	%			55.9	%			61.6	%
			20	%			173.9				263.9				352.8				441.3				529.4				617.5				705.5						20	%			22.3	%			30.1	%			37.1	%			43.8	%			50.0	%			56.0	%			61.7	%

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19.8 Conclusion – Economic Analysis

Based on the assumptions and parameters presented, the FS shows positive economics supported by a post-tax NPV_5% of $374.7 million and post-tax IRR of 38.9%. The initial Capex is at $189.8 million, with undiscounted LOM revenue of $1,410.6 million, sustaining Capex of $65.1 million, all-in Operating cost of $469.1 million, and closure costs of $21.1 million.

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20 ADJACENT PROPERTIES

This section is not relevant to the report.

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21 OTHER RELEVANT DATA AND INFORMATION

This section is not relevant to the report.

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22 INTERPRETATION AND CONCLUSIONS

22.1 Introduction

The QPs note the following interpretations and conclusions in their respective areas of expertise, based on the review of data available for this Report.

22.2 Mineral Tenure, Surface Rights, Water Rights, Royalties and Agreements

Information from legal experts support that the tenure held is valid and sufficient to support a declaration of Mineral Resources and Mineral Reserves. Tenure is in the geographic area referred to as the Grassy Mountains claims group. The Grassy Mountain deposit is within the Grassy Mountains claims group.

Paramount’s 100% ownership of the Grassy Mountain Project is subject to underlying agreements and royalties.

Seabridge Gold is entitled to a 10% net profits interest (NPI) royalty. Seabridge Gold, at the Report effective date, is the second largest Paramount shareholder and has indicated that it will convert its NPI into equity in Paramount, thus the Seabridge NPI has not been included in the FS.

Sherry and Yates retain a 1.5% royalty of the gross proceeds for the production of minerals from the patented and unpatented claims and a surrounding ¹⁄₂ mile area of interest. This area covers the Grassy Mountain deposit. There are an additional two royalty obligations in the Project area; however, these are not over claims that host Mineral Resources or Mineral Reserves.

Paramount holds three patented claims over the Grassy Mountain deposit, which provides surface rights for that area. The surrounding surface rights associated with the proposed locations of the Project surface facilities belong to the Federal government and are managed by the Vale District BLM office.

Paramount holds a water right granted by the Oregon Water Resources Department to Calico.

Except for the exploration surface disturbance, primarily related to drilling, and the network of water wells that will need to be reclaimed, there are no known environmental liabilities associated with the Grassy Mountain Project.

To the extent known to the QP, there are no other significant factors and risks that may affect access, title, or the right or ability to perform work on the Project that are not discussed in this Report.

22.3 Geology and Mineralization

The Grassy Mountain deposit is an example of a low-sulfidation epithermal deposit.

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The understanding of the Grassy Mountain deposit settings, lithologies, mineralization, and the geological, structural, and alteration controls on mineralization is sufficient to support estimation of Mineral Resources and Mineral Reserves.

22.4 Exploration

The exploration programs completed to date are appropriate for epithermal-style mineralization.

22.5 Analytical Data Collection in Support of Mineral Resource Estimation

Sampling methods are acceptable for Mineral Resource estimation.

Sample preparation, analysis and security are generally performed in accordance with exploration best practices and industry standards at the time the information was collected.

The quantity and quality of the logged geological data, collar, and downhole survey data collected in the exploration and infill drill programs are sufficient to support Mineral Resource estimation.

No material factors were identified with the data collection from the drill programs that could significantly affect Mineral Resource estimation.

The sample preparation, analysis, and security practices and are acceptable, meet industry-standard practices at the time they were undertaken, and are sufficient to support Mineral Resource estimation.

QA/QC submission rates met industry-accepted standards at the time of the campaign. The QA/QC programs did not detect any material sample biases in the data reviewed that supports Mineral Resource estimation.

The data verification programs concluded that the data collected from the Project adequately support the geological interpretations and constitute a database of sufficient quality to support the use of the data in Mineral Resource estimation.

22.6 Metallurgical Testwork

Metallurgical testwork and associated analytical procedures were appropriate to the mineralization type, appropriate to establish the optimal processing route, and were performed using samples that are typical of the mineralization styles found within the Grassy Mountain deposit. Whole ore gold/silver leaching with cyanide and recovery with activated carbon is a well-established and effective method for extracting and recovering gold and silver from free milling deposits like Grassy Mountain.

Samples selected for testing were representative of the mineralization. Samples were selected from a range of depths within the deposit. Sufficient samples were taken so that tests were performed on sufficient sample mass.

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Recovery factors estimated are based on appropriate metallurgical testwork and are appropriate to the mineralization and the selected process route. Overall plant recoveries for gold are predicted to range from 89.5–94.9% for head grades of 0.096–0.508 oz/ton (3.3–17.4 g/t) Au over the LOM. Overall plant recoveries for silver are predicted to range from 62.7–80.4% for head grades of 0.161–0.523 oz/ton (5.5–17.9 g/t) Ag over the LOM.

Mercury is present in sufficient concentration in the ore to warrant removal and management, and a mercury retort step has been incorporated into the flowsheet. Arsenic is present in the feed but at low concentrations of 3.47–5.34 oz/ton (119–183 g/t) that are not expected to be problematic in processing. No other elements that may cause issues in the process plant or concerns with product marketability were noted.

22.7 Mineral Resource Estimation

The Grassy Mountain project’s estimate of mineral resources is reported using the definition in Subpart 229.1300—Disclosure by Registrants Engaged in Mining Operations in Regulations S-K 1300.

RESPEC estimated the Grassy Mountain project’s mineral resources considering potential mining by open pit methods, with the addition of a minor amount of underground-mineable resources lying immediately outside the pit walls of the lower portion of the pit. An alternate scenario, comprised exclusively of mining the higher-grade portion of the deposit by underground methods, is also realistic, and this scenario was chosen to define the project mineral reserves. RESPEC constructed the resource model to accommodate both mining scenarios.

During resource modeling, RESPEC identified structural zones as the principal controls of high-grade mineralization within the central core of the Grassy Mountain deposit. This high-grade mineralization has significant grade variability, which creates modeling uncertainties with respect to the location of the estimated high grades as distances from drill data increase. While open-pit mining would minimize the risk imparted by the location uncertainty, underground mining requires far greater spatial accuracy. The current model is not sufficiently accurate for use in mining, particularly from underground. Properly oriented, closely spaced, definition drilling would therefore be required to update the operation’s short- and long-term resource models and to refine geotechnical modeling and final stope designs. To reduce the uncertainties in the high-grade mineralization model, RESPEC strongly recommends drilling from the surface prior to mining. Drilling on tighter spacing for more precise delineation of the high-grade mineralization and stope design would take place from underground. Underground drilling would also be important from a geotechnical standpoint, as the high-grade mineralized structures are typically characterized by poor to very poor rock quality.

A total of 14,947 sample intervals in the drill-hole database have gold assays but no silver analyses. In most of these cases, entire drill holes were not assayed for silver. For example, some of the early Atlas holes and all the Newmont holes were not assayed for silver. A total of 4,720 of the sample intervals lacking silver assays lie within the domains that form the basis of the gold and silver resource estimates, while 19,938 sample intervals used in the resource estimates do have silver analyses. However, the fact that silver adds very little value relative to gold mitigates the risk posed by the lower quantity of silver analyses.

RESPEC believes that all factors that influence the prospect of economic extraction have either been addressed or could be resolved by further drilling. RESPEC is not aware of any unusual environmental, permitting, legal, title, taxation, socio-economic, marketing, political, or other relevant factors not discussed in this technical report that could materially affect the mineral resource estimates as of the effective date.

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22.8 Mineral Reserve Estimates

An underground mining scenario is assumed using mechanized cut-and-fill methods.

The Proven and Probable Mineral Reserves for Grassy Mountain were estimated by first calculating an economic cut-off grade for mining underground stopes, then using the cut-off grade to design stope shapes centered on Measured and Indicated Mineral Resource blocks with gold grades greater than or equal to the cut-off grade.

The calculated gold cut-off grade is 0.08 oz/ton Au. Silver was not included in the cut-off grade calculation due to its relatively small contribution (2%) to total economic value.

The economic stope cut-off grade was used in the stope optimization to identify the Measured and Indicated blocks available for consideration to be converted to Mineral Reserves. Measured and Indicated resource blocks with grades less than the economic stope cut-off grade were applied to internal dilution.

A modifying factor of 8% was used for calculating external dilution tons. All Inferred resource blocks or partial blocks within the stopes and all unclassified material within the stopes is considered internal dilution. The tons were accounted for with zero grade.

Mining recovery is estimated to be 97% based on an assumed ore loss of 3%. This is considered appropriate for the highly selective mechanized cut-and-fill mining method selected for the Grassy Mountain deposit and it is based on similar operations in disseminated ore bodies.

The Mineral Reserve estimation for the Project is reported using the definition in Subpart 229.1300—Disclosure by Registrants Engaged in Mining Operations in Regulations S-K 1300.

The Mineral Reserve estimation for the Project conforms to industry-accepted practices and is reported using the 2014 CIM Definition Standards.

The QP is not aware of any mining, metallurgical, infrastructure, permitting or other relevant factors not discussed in this Report that could materially affect the Mineral Reserve Estimate.

22.9 Mining Method

The estimated mine life is 9.3 years.

The Grassy Mountain mine will be an underground operation accessed via one decline and a system of internal ramps. The decline will be 15ft x 15ft in dimensions, developed from a portal on surface.

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An underground mining scenario is assumed using underhand mechanized cut-and-fill methods, which, following ramp-up, will produce 1,300–1,400 tons/day, four days a week. This mining rate will provide sufficient material for the 750 tons/day mill and processing plant to operate at full capacity for seven days a week. The mechanized cut-and-fill method is highly flexible and can achieve high recovery rates in deposits with complex geometries, as is the case at the Grassy Mountain deposit.

Level stations will have a standoff distance from the orebody of approximately 300 ft. There are five stations planned for the mine, accessed off the decline, and each station will access up to five production levels.

The ventilation network was designed to comply with U.S. ventilation standards for underground mines. The planned ventilation will use a push/pull system and will require one exhaust fan on surface. One set of stacked ventilation raises is included in the design to be used for ventilation and secondary egress. Cemented rock fill (CRF) will be used for backfill. Mine operations will be based on the usage of mobile mining equipment suitable for underground mines. Equipment is conventional for mechanized cut-and-fill mining operations.

22.10 Geotechnical Considerations

The Grassy Mountain deposit is in a structurally complex, clay-altered, epithermal environment. Rock mass conditions in the infrastructure and production areas vary from Poor to Fair quality with the poorest conditions within major structures that run longitudinally through and bound the deposit. Outside of these fault areas, rock mass conditions are generally Fair. However, localized zones of Poor ground potentially associated with secondary structures or locally elevated alteration intensity are present throughout the planned mining area.

The North and Grassy faults are significant fault structures that pose a risk to the stability of an open stoping method; hence, these areas are considered suitable only for a limited man-entry mining method such as mechanized cut-and-fill, where conditions can be well controlled.

Degradation of Grassy Mountain Formation lithologic units results in difficult mining conditions that can be mitigated through additional ground support. This would result in a higher mining cost with slower advance rates in those areas.

Based on the shallow depth, ground stress is relatively low, and rock damage due to higher mining-induced stress concentrations is only anticipated in high-extraction or sequence closure areas and weaker rock mass areas. However, a reduction in the mining stresses around excavations is likely to adversely affect the stability of large open-span areas. Tensile failure and gravity-induced unraveling are foreseen as the main failure mechanisms.

Ground support design considers industry-standard empirical guidelines and GMS’s experience in variable ground conditions. Compromises have been made in the extraction sequence due to the need to balance grade and production profiles, extraction of wide orebody areas, and other geotechnical constraints. Ultimately, some aspects of the sequence may not be geotechnically optimal, and additional analysis or design may be required.

Ground support design considers industry-standard empirical guidelines and GMS’s experience in variable ground conditions. The extraction sequence has been developed to balance geotechnical constraints, ore recovery, production requirements and project economics. Based on the 2026 FS Update review completed by GMS, the updated mine planning information remains generally consistent with the previously established underground geotechnical design basis. Nevertheless, local refinements to excavation sequencing, support requirements and extraction strategies may be warranted during future detailed engineering, mine development and operations as additional geotechnical information becomes available.

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22.11 Processing and Recovery Methods

The process plant will be designed with conventional processing unit operations frequently used within the gold processing industry. The process plant will treat 750 tons/day and will operate with two 12-h shifts per day, 365 days per year, producing gold doré bars. The major equipment within the process plant is specified in accordance with the climate, site conditions, ore grades and metallurgical performance outlined in this report. Any deleterious metals present in the ore such as mercury will be abated by specialized equipment installed in the process plant and are not expected to impact payability terms.

22.12 Infrastructure

22.12.1 Key Infrastructure

Key Project infrastructure as envisaged in the FS includes: underground mine, including portal and decline; roads; site main gate and guard house; administration building, training, first aid, change house and car park; process plant e-room; crushing area e-room; control room; reagent storage and building; gold room; assay laboratory and sample preparation area; plant workshop and warehouse; truck shop, warehouse, wash pad; fuel facility, fuel storage and dispensing; water wells; 14.4 kV overland power line; fresh water supply and treatment; raw water tank; TSF; TWRSF; and explosives magazine.

22.12.2 Roads and Power

The main access road will use an existing BLM road, which will be widened to support operations.

Power will initially be provided by diesel power generators during the construction period (year 1). A power line will be built to site in that first year and will deliver approximately 5.3 MW. The generators will remain on site as backup.

22.12.3 Waste Rock Storage and Borrow Pits

Waste rock will be temporarily stored on surface in a lined facility and will be returned underground as CRF.

Two borrow pits are planned, using contract mining. Borrow material will be used for construction, backfill, and reclamation.

22.12.4 Tailings Storage Facility

The TSF uses conventional designs and assumes construction in three primary stages and zero discharge. The facility will be constructed in stages (with Stage 1 constructed in two intermediate phases), as only 2.4 million tons are planned to be delivered to the TSF, only Stage 1, 2, and a portion of Stage 3 will be required. The TSF will fill the broad valley

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immediately west of the Grassy Mountain mine portal and process facilities and require embankments on the north and west sides to impound the tailings. The main embankment will cross the natural drainage on the north side of the TSF, and a secondary embankment will be constructed along the western ridge. The facility will be a 100% geomembrane-lined facility with a continuous, engineered lining system extending across the impoundment basin and the upstream slope of the embankments. The design is capable of storing runoff from tributary areas and direct precipitation on the facility resulting from the 500-year, 24-hour storm event, as well as an allowance for wave run-up due to wind action.

The relevant results and interpretations related to the TSF design are based on the data and other information summarized in this Report.

Golder provided a detailed design for the TSF sufficient to contain the tailings projected from this study’s life of mine production (Golder, 2021d). At this stage of the Project, there is reasonable certainty that the location and design of the TSF and TWRSF as presented for Study will be used as planned. No significant design changes are likely to be required provided that no material changes in location or design are needed as a result of the on-going local, State, and Federal permitting process.

Provided that actual construction, operation, management, and closure of the TSF do not differ materially from the results and design parameters summarized in this Report, there are no significant risks and uncertainties that could reasonably be expected to affect the reliability or confidence in the TSF design and cost estimates.

If actual activities related to the construction, management, operation, and closure of the TSF do differ materially from the results summarized in this Report, then the reasonably foreseeable impacts of these risks and uncertainties are most likely to be project delays and additional costs. However, any such delays or additional costs may reasonably be expected to be managed in the ordinary course and should not impact overall Project viability.

22.12.5 Water Management

Contact and non-contact surface water will be routed around the plant site. Permanent channels were designed on a 100-year, 24-hour storm event with nine inches of freeboard, or 500-year, 24-hour storm event without overtopping. Temporary channels were designed for a 25-year, 24-hour storm event with nine inches of freeboard, or 100-year, 24-hour storm event without overtopping.

22.12.6 Water Supply

Water supply from the raw water production wells and mine dewatering is projected to be sufficient to support the operational demands. Water demands are expected to vary seasonally.

22.13 Markets and Contracts

No market studies have been completed. Gold and silver are freely-traded commodities. The doré that will be produced by the mine is considered to be readily marketable with no deleterious/penalty elements. Although mercury is present in the ore, a retort and recovery system has been included to maintain doré quality.

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Metal pricing used in the economic analysis is based on long-term flat metal prices of $3,600/oz Au, and $48.00/oz Ag, which are based on consensus forecasts from various financial institutions.

Paramount has no current contracts for property development, mining, concentrating, smelting, refining, transportation, handling, sales and hedging, forward sales contracts or arrangements.

22.14 Environmental, Permitting and Social Considerations

Permitting activities began in 2012 with engagement with the state and federal agencies and collection of baseline data. The draft CPA was submitted to DOGAMI in 2019 for review and comment by state agencies which were received by Calico and integrated into the final CPA. In December 2021, Calico submitted the final CPA to DOGAMI. Calico and DOGAMI have been working together as the draft permits have been developed and are in the process of being finalized. The package of draft permits was issued for public review on December 8, 2025. Final permits are anticipated to be issued by all required state agencies in the second half of 2026.

In December 2021, Calico submitted a Plan of Operation (PoO) to the BLM. The draft EIS was published for public comment on August 8, 2025 and the final EIS and record of decision was published on January 29, 2026. This record of decision provides federal authorization for the PoO following posting of a reclamation bond.

Paramount has been conducting baseline data collection for over ten years for environmental studies required to support the State and Federal permitting process. Results indicate limited biological and cultural issues, air quality impacts appear to be within State of Oregon standards, traffic and noise issues are present but at low levels, and socioeconomic impacts are positive. The result of the geochemical characterization identified that the geochemistry of the ore and waste rock provide for a possible source of future environmental issues as the Grassy Mountain Project is developed.

Data produced during the baseline and geochemical studies were used in the Project design process, including the design and operation of the TSF and handling and use of waste rock as cemented backfill material, specifically considering environmental impacts. As outlined in Section 15, the design of the TSF and the waste rock management plan used the results of this geochemical characterization work.

A closure plan and RCE were submitted to the BLM and DOGAMI as part of PoO and CPA, respectively. The proposed reclamation approach for the Project includes sealing the mine portal, lining, capping, and revegetating the TSF supported by temporary active solution management followed by passive solution management (evaporation) as the TSF drains down, the removal and offsite disposal of the temporary waste rock storage facility liner, process plant and other infrastructure, the demolition and offsite disposal of the powerline and associated infrastructure, and in general the grading, capping, and revegetation of disturbed areas. This approach will result in two post-reclamation landforms, the TSF and the quarry, and is anticipated to be completed within five years of ceasing operation. Post-reclamation monitoring, including groundwater and stormwater quality and revegetation success, is proposed to meet Federal and State requirements and guidance and will continue for up to 30 years following reclamation.

The RCE was updated in February 2026 to account for current unit rates and in response to input from DOGAMI and BLM during the permitting process. The reclamation surety associated with the proposed reclamation plan is $21,086,123 USD including indirect costs such as contingency, contractor management and contractor profit. The BLM and State of Oregon are in negotiations to establish an MOU allowing the State of Oregon to hold the bond and oversee the reclamation activities.

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Social and community impacts have been considered and evaluated for the PoO in accordance with the NEPA and other Federal laws, and the State of Oregon Socioeconomic Analysis. Potentially affected Native American tribes, tribal organizations and/or individuals were consulted during the preparation of the PoO and consultation continues to advise on the project that may have an effect on cultural sites, resources, and traditional activities.

22.15 Capital Cost Estimate

The capital cost estimate is reported in Q2 2026 USD. The capital costs are at a minimum at a feasibility level of confidence of ±15% as is defined in S-K 1300.

Capital costs are estimated at $189.8 million of initial capital. This figure includes $1.7 million of capitalized operating costs and $19.8 million in contingency (10%). In addition, there is $65.1 million of sustaining capital over the LOM and $21.1M in closure costs.

22.16 Operating Cost Estimate

The operating cost estimates are reported in Q2 2026 USD. The capital costs are at a minimum feasibility level of confidence of ±15% as is defined in S-K 1300.

The LOM underground mining costs are estimated at $332.9 million over the LOM, and averages $141.18/ton processed over the LOM. Excluding mining costs from the pre-production period (accounted for in the initial capital cost) results in an average mining cost of $140.60/ton processed over the LOM.

The LOM process operating cost is estimated at $89.3 million over the LOM, and averages $37.72/ton processed over the LOM.

The LOM general and administrative (G&A) costs are estimated at $5.4 million/a, or $48.7 million over the LOM, and average $20.65/ton processed over the LOM.

22.17 Economic Analysis

An economic model was developed to estimate the project’s annual pre-tax and post-tax cash flows, sensitivities, and NPV results using a 5% discount rate. Based on the assumptions and parameters, the economic analysis shows positive post-tax economics of $374.7 million NPV_5% and 38.9% post-tax IRR. A sensitivity analysis was conducted on the base-case pre-tax and post-tax NPV and IRR of the project using the following variables: metal prices, discount rate, operating costs, initial capex, metal recovery, and head grade.

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22.18 Risks and Opportunities

22.18.1 Risks

22.18.1.1 Geological Setting, Mineralization, and Deposit

Unlike states such as Nevada and Arizona, Oregon does not have a strong mining background. The Project may encounter a lack of mining skills and expertise at the local level, which could affect Paramount’s ability to operate using local labor, until Paramount has trained sufficient local staff to suit Project requirements. There may also be effects on the Project caused by a lack of familiarity with Mine Safety and Health Administration (MSHA) requirements at the local and State levels and at the local staff operator level, which may in turn lead to safety incidents. Such incidents could result in Project delays and affect the permitting process.

22.18.1.2 Mineral Processing and Metallurgical Testing

If material flowability properties in the mined product are not aligned to the analysis and benchmarking completed in this FS, there is a risk of delayed production ramp-up as well as remedial corrections required to the crushing circuit design. To mitigate this, additional materials flowability testwork should be completed on the mined product prior to detailed design.

22.18.1.3 Mineral Resource Estimate

During resource modeling, RESPEC identified structural zones as the principal controls of the high-grade mineralization in the central core of the Grassy Mountain deposit. This mineralization has significant grade variability, which creates modeling uncertainties with respect to the location of the estimated high grades as distances from drill data increase. While an open-pit mining scenario would minimize the risk imparted by the location uncertainty, underground mining would require far greater spatial accuracy. The current model is not sufficiently accurate for use in mining, particularly from underground. Updating the operation’s short- and long-term resource models, refining geotechnical modeling, and making final stope designs requires properly oriented, closely spaced, definition drilling. RESPEC strongly recommends drilling from the surface prior to mining to reduce the uncertainties in the high-grade mineralization model. Drilling on tighter spacing for more precise delineation of the high-grade mineralization and stope design would take place from underground. The underground drilling would also be important from a geotechnical standpoint because the mineralized structures are typically characterized by poor to very poor rock quality.

22.18.1.4 Mining Methods

There is a risk that the estimated mining costs may not be achievable if additional support over that contemplated in the FS is required due to weak rock mass.

22.18.1.5 Infrastructure

Delays in the power line installation including the substation upgrade may result in delays to the Project schedule. As the Project power requirements are relatively modest, there is a risk that the selected power provider may delay supply to the Project. However, power for the initial stages of project development can be generated using diesel-powered generators prior to the power supplier completing the requisite power infrastructure for the Project.

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Water supply is envisaged to be partly from groundwater sources. Additional production wells may be required to support operations, which will require permitting. In addition, well productivity may not be as envisaged, which may affect both the volume of water available for operations and the number of wells that must be pumped.

If additional borrow areas are required for construction and reclamation of the TSF that are more distant than contemplated in the FS, then reclamation construction costs of the TSF will increase as compared to the costs estimated in this Report.

As construction work in Oregon is seasonal, poor weather during the construction season may result in delays to the Project schedule. This is de-risked by scheduling earthworks and building construction in summer, with mill construction during winter months to be completed within a building.

22.18.1.6 Environmental Studies, Permitting and agreements with local individuals or groups

If non-governmental organizations object to the Project as envisaged in the FS, a number of risks may result. These could include additional capital costs or increases in operating costs, delays in Project permitting, and delays in obtaining the social license to operate.

22.18.1.7 Capital Costs

There is a risk that the estimated mining capital costs may not be achievable due to the following factors:

• Significant variations in tariffs could result in costs exceeding those assumed in the project estimates.

• Additional ground support, beyond what is contemplated in the Feasibility Study (FS), may be required if a greater extent of weak rock mass is encountered.

• Increased demand for mining equipment may lead to delays in the delivery of planned equipment, potentially impacting the project schedule. Furthermore, if alternative equipment must be procured, the costs may differ from those assumed in the current estimate.

22.18.1.8 Operating Costs

There is a risk that the estimated mining capital costs may not be achievable due to the following factors:

• Additional ground support, beyond what is contemplated in the Feasibility Study (FS), may be required if a greater extent of weak rock mass is encountered.

• Increases in commodity prices (e.g., diesel, cement, steel) may lead to higher costs for raw materials and supplies used in mining operations, resulting in increased operating costs.

• Non-availability of skilled manpower may necessitate offering higher compensation to attract and retain qualified personnel, potentially increasing operating costs. Additionally, there is a possibility that production mining activities may need to be outsourced, which could further increase operating costs, although it may help reduce capital expenditures.

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22.18.1.9 Economic Analysis

The economic analysis is based on long-term flat metal prices of $3,600/oz Au, and $48.00/oz Ag, which are based on consensus forecasts from various financial institutions, with no considerations for escalation or inflation over the LOM. Large fluctuations to metals prices or drastic changes to inflation can negatively impact the project returns.

The risks or uncertainties that could reasonably be expected to affect the reliability or confidence in the projected economic outcomes are:

• Geological and resource uncertainty

• Metallurgical and processing uncertainty

• Mining and geotechnical uncertainty

• Infrastructure assumptions

• Capital and operating cost uncertainties

• Commodity price and market risks

• Environmental, permitting, and regulatory risks

• Social and community considerations

• Political and jurisdictional risk

• Project schedule assumptions

22.18.1.10 Operational Readiness

Mining is cyclical, and during an up-cycle, it can be difficult for any mining operation to attract quality staff. There is a cost risk to Paramount to source a non-local operations team of sufficient experience and expertise, including additional costs to train and mobilize the team locally, to adequately support the Owner’s team.

Implementation of an effective operations readiness strategy and program is key to address the potential risk that Paramount currently has no active operations. A lack of familiarity with the operational environment, particularly in Oregon, could otherwise result in unexpected Project delays or cost increases.

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22.18.2 Opportunities

22.18.2.1 Geological Setting, Mineralization, and Deposit

There is remaining exploration potential in the Project area. The Crabgrass, Bluegrass, North Bluegrass, Ryegrass and Dennis’ Folly areas in the Grassy Mountain claims block were recommended for surface work with the goal of defining further exploration drill targets.

22.18.2.2 Mineral Processing and Metallurgical Testing

There is an opportunity to further optimize the flowsheet with respect to leach feed particle size and retention time that could positively affect the project economics, further comminution and metallurgical testwork work should be completed to confirm the opportunity.

22.18.2.3 Mining Methods

The mine plan and cut-off grades used for the FS are based on conservative metal prices. There may be upside for the Project in higher metal pricing scenarios. A higher metal price would potentially result in additional material meeting the cut-off grade criteria and being available to potentially convert to Mineral Reserves, thereby providing additional metal production and potentially, extending the mine life.

22.18.2.4 Infrastructure

The mine plan requires sources of aggregate and borrow materials in support of road construction and CRF. Private sources for gravel construction along the access route may be obtainable. There may also be an opportunity to source borrow material from local sources. This could lead to more simplified permitting for the development of these sources, and it could potentially reduce costs of the gravel for the access road construction and borrow materials for CRF.

22.18.2.5 Environmental Studies, Permitting and agreements with local individuals or groups

The current post-closure land use is to return the site to a land use similar to current land uses (grazing, wildlife, recreation). There is the opportunity to modify the closure plan to result in a beneficial post-closure land use that may be identified as the project progressed through construction and operation.

22.18.2.6 Capital Costs

The following factors present potential opportunities to optimize project outcomes and enhance value:

• Tariff variability: potential fluctuations in tariffs provide an opportunity to optimize procurement strategies, renegotiate contracts, or identify alternative suppliers to achieve cost efficiencies relative to current project estimates.

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• Ground conditions and support requirements: encountering varying rock mass conditions offers an opportunity to refine ground support design, improve geotechnical understanding, and implement more efficient or innovative support systems tailored to actual conditions.

• Mining equipment market dynamics: increased demand for mining equipment creates an opportunity to reassess fleet strategy, including evaluating newer or more efficient technologies. Exploring alternative equipment sourcing or leasing options may also optimize capital allocation and improve operational flexibility.

22.18.2.7 Operating Costs

The following factors present potential opportunities to optimize project outcomes and enhance value:

• Ground conditions and support requirements: encountering varying rock mass conditions offers an opportunity to refine ground support design, improve geotechnical understanding, and implement more efficient or innovative support systems tailored to actual conditions.

• Commodity price movements: changes in commodity prices (e.g., diesel, cement, steel) present opportunities to implement cost-control measures, adopt more efficient consumption practices, or explore bulk purchasing and long-term supply agreements to mitigate cost impacts.

• Workforce availability and strategy: labor market constraints provide an opportunity to strengthen workforce planning, invest in training and development, or adopt automation and productivity-enhancing technologies. Additionally, selectively contracting production mining could optimize the balance between operating and capital costs while improving scalability and execution efficiency.

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23 RECOMMENDATIONS

23.1 Introduction

Based on the assumptions and parameters presented in the Report, the Grassy Mountain Project has a mine plan that is technically feasible and economically viable. The positive financials of the Project ($374.7 million post-tax NPV_5% and 38.9% post-tax IRR) support the mineral reserve.

A single work phase is proposed for recommended work to further derisk the project in advance of the next phase of the project (detailed engineering). The estimated budget to complete the work program is set out by discipline area and summarized in Table 23-1.

Table 23-1: Phase 1 Recommended Work Program

Program Component		Cost ($ M)
Metallurgical testing		0.2
Drilling and Lithologic Modelling		2.5
Mining methods		0.1
Geotechnical		0.5
Hydrology		0.6
Infrastructure		0.1
Environmental Studies, Permitting and agreements with local individuals or groups		—
Total		4.0

Note: totals may not match due to rounding

23.2 Metallurgical Testing

It is recommended that further comminution and metallurgical testwork be completed, particularly on material to be processed in the first three years of operations in order to investigate the opportunity of optimizing the comminution flowsheet and/or the opportunity to defer some equipment and capital costs into later years. Estimated cost $175,000.

It is recommended that material handling testwork be completed to optimize and de-risk material handling design of conveyors, bins and stockpiles and potential operating issues associated with solids bridging or rat holes. Estimated cost $75,000.

23.3 Mineral Resource Estimate

The current lithologic model has not been fully rectified three-dimensionally. To support an active mining operation, a fully rectified lithological model is recommended. This work is estimated to cost about $45,000.

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To mitigate some of the risks associated with significant grade variability observed in the structural zones that are the principal controls of the high-grade mineralization within the central core of the Grassy Mountain deposit, a surface drilling program is recommended. The current model is not sufficiently accurate for use in mining, particularly from underground. Properly oriented, closely spaced, definition drilling would be required to update the operation’s short- and long-term resource models, as well as to refine geotechnical modeling and final stope designs.

Before mining commences, drilling from the surface is strongly recommended to improve the understanding of the high-grade mineralization model. The drilling would consist of 25 RC holes with core tails for a total of 19,250 ft and would target gaps in the high-grade core where the location and orientation of the mineralization is uncertain. The estimated cost for the drilling program is estimated at $2,525,000, as given in Table 23-2.

Table 23-2: Recommended Work Program for Mineral Resource Estimate

Program Component		Unit Cost ($)				Quantity				Task Cost ($)
3-D lithologic modeling			N/A				N/A			45,000
Drilling - RC			$66/ft				9,900 ft			654,000
Drilling - core			$131/ft				9,350 ft			1,229,000
Road and pad construction, reclamation			$233/hour				60 hours			14,000
Assays			$70/sample				4000 samples			280,000
Travel, lodging, field supplies, personnel			$1,685/day				180 days			303,000
Total										2,525,000

Drilling on tighter spacing from underground for more precise delineation of the high-grade mineralization and stope design will be required following the surface drilling program. The drilling would also be important from a geotechnical standpoint as the mineralized structures are typically characterized by poor to very poor rock quality. The drilling would take place during development of the mine, so no work program or cost estimate are included here. However, more precise definition of the deposit from underground will be critical for effective stope design, mine planning and geotechnical characterization.

23.4 Mining Methods

Additional optimization of mine design and underground production should be undertaken before construction begins. This should include:

• Determination of an optimal gold price. A higher gold price will lower the cut-off grade and bring in more economic material into the mine plan. Detailed mine plan will be required to design level access heading meeting design gradients such that it is ready for execution. This is estimated to require a budget of approximately $30,000 to complete.

• Further analysis of the underground equipment types and sizes to identify possible improvements to the economics and efficiencies. Support with bidding and bids evaluations will be required. A budget of $15,000 is recommended to complete this step.

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• Contractor mining bids development and evaluation of bids. A budget of $15,000 is recommended to complete this step.

• Further analysis of the underground ventilation system should be completed. This analysis should include a further detailing of the ventilation model, fan selection, and ventilation raise diameter. This is estimated to require a budget of approximately $15,000 to complete.

The mining recommendations overall have a completion cost estimated at approximately $75,000.

Table 23-3: Recommended Work Program for Mining Methods

Program Component		Unit Cost ($)
Mine Design Detail			30,000
Equipment Selection and Bids			15,000
Contractor Mining			15,000
Ventilation Model and design			15,000
Total			75,000

23.5 Geotechnical

A geotechnical classification should be used for narrow zones of weakness, both in rock core descriptions and during underground geotechnical mapping, to allow for the differentiation, characterization, and geotechnical classification of clay matrix breccias, faults, faults/veins or other weakness zones. This was not analyzed in the FS due to lack of structural information.

A study should be completed to geotechnically characterize the vein/faults and document strength properties and mean thicknesses.

The seismic hazard study should be updated to provide additional quantification of the seismic risk for the Project area.

The empirical design using a lower Q’ value standard deviation range should be reviewed to determine the stability condition of all development and determine what additional stability measures may be required if designs change due to a more conservative assessment of the Q’ values.

A pillar dimensioning and stability analysis is recommended to be completed to provide recommendations to the mine design and planning department.

Additional tests should be undertaken to test CRF strength resistance in response to changes in the cement and fly ash percentages to reduce the amount of cement that may be required.

A limit equilibrium analysis should be completed to assess the typical failure modes of caving, flexural, sliding and rotational as proposed by Mitchell and Roettger (1989).

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Reinforcements should be installed during operations to intersect the vertical joints at an oblique angle to improve the shear resistance. Otherwise, vertically-installed reinforcements may need to be longer than envisaged in this Report to penetrate beyond the potential height of the stable arch.

Wall response in permanent and temporary excavations must be measured during excavation to develop a better understanding of the interaction between bolts, cable bolts and the rock mass.

A geotechnical risk model is recommended to economically quantify the risk of instabilities and prepare alternative plans to ensure on time ore delivery.

An update should be undertaken to the reinforcement and support numerical analysis to support the shotcrete assumptions.

The three-dimensional numerical analysis of the timeframes assumed for excavation and backfill should be conducted on a month-by-month basis. This monthly examination should evaluate displacement velocity against the stand-up time requirements for the excavations.

Rib pillars that are lower than three drifts wide in drift excavations under rock mass environments (i.e. that are not under CRF) should be avoided, due to the risk of high stress concentrations in the pillar and therefore local instabilities.

The safety factor should be calculated as part of the numerical model update, to provide information on the response of the rock mass to the induced stress through the excavation–backfill process.

Paramount should prepare a detailed monitoring plan for underground operations. The plan should include:

• geotechnical inspections and permanent ground control during operations;

• installation of vibrating wire extensometers to measure displacements along time in sectors considered critical as the permanent infrastructure;

• a measurement program for in-situ stress parameter, to indicate sectors subject to large compression or relaxation changes due to stress redistribution during drift mining;

• preparation of procedures for a systematic convergence measurement and stress changes measurement; and

• surface displacements monitoring based on visual inspection, cross-crack measurements (either manual or by wireline extensometer), survey monitoring and satellite imaging subsidence monitoring (InSAR).

The application of pre-splitting blasting process or smooth blasting processes should be investigated to reduce blast damage and achieve blast design.

Blasting should be avoided beside drifts that have recently been backfilled or where the CRF still undergoing the curing process (28 days) to prevent CRF damage and affect the CRF stability in undercut operations.

A vibrations study is recommended to define the maximum size of blasting to reduce the risk of underground collapses or instabilities.

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The effect of blasting on the weak rock mass should be quantified using techniques proposed by Caceres (2011) related to peak particle velocity and scaled distance as a function of rock mass quality.

A workshop should be organized to review the mine plan and geotechnical assumptions to optimize the mine plan so as to ensure stability between drifts and mine levels.

For the portal excavation, a 2D numerical model should be completed to assess stability and deformation during the excavation process. The model should consider the updated geotechnical characterization and assess these conditions at different excavation stages.

The total geotechnical program is estimated to cost approximately $455,000 to complete, detailed in Table 23-4 below.

Table 23-4: Recommended Geotechnical Program

Program Component		Unit Cost ($)
Vein/faults geotechnical characterization			40,000
Seismic hazard study update			50,000
Design stability update and pillar assessment			10,000
CRF test update			200,000
CRF limit equilibrium assessment			10,000
Geotechnical risk model			15,000
Support numerical analysis update			10,000
3D stability numerical analysis update			35,000
Detailed ground monitoring plan			10,000
Effect blasting assessment			10,000
Numerical model for portal excavation sequence			10,000
Mining and geotechnical workshop			25,000
Other studies			30,000
Total			455,000

23.6 Hydrology

Wellfield construction should be initiated and pumping tests conducted to confirm the water flow available from the water well. This work is estimated at approximately $600,000.

23.7 Infrastructure

Detailed engineering and design should be carried out on the incoming power line, by the local power provider. The anticipated cost for this study is approximately $100,000.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 323 May 27, 2026

23.8 Environmental Studies, Permitting and agreements with local individuals or groups

Continued engagement with the local community, tribal entities and local, state and federal agencies is recommended as the project nears final state permitting, construction and operation. Costs associated with this recommendation are a part of ongoing engagement and already included in Owner’s costs.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 324 May 27, 2026

24 REFERENCES

Barton, N., 2002: Some New Q-Value Correlations to Assist in Site Characterization and Tunnel Design: Int. J Rock Mech and Min Sci, (39), pp.

185–216.

Barton, N., 2008: Rock Engineering for a Drill and Blast and TBM Tunneling, and Important Aspects of Rock Joint and Rock Mass Behavior: Short course presented 26–27 June 2008, Santiago, Chile.

Barton, N.; Lien, R. and Lunde, J., 1974: Engineering Classification of Rock Masses for the Design of Tunnel Support: Rock Mechanics, Vol. 6, N° 4.

Baxter, K., 2020: Grassy Mountain Gold and Silver Project Mine Dewatering Hydrogeologic Assessment: report prepared by Lorax Environmental Services, March 2020, Project Number A547-1.

Bieniawski, Z. T., 1976: Rock Mass Classification in Rock Engineering: in Z. T. Bieniawski, ed. Proceedings of the Symposium on Exploration for Rock Engineering, Vol. 1. Johannesburg, 1–5 November 1976. Cape Town: A.A. Balkema, pp. 97–106.

Bieniawski, Z. T., 1989: Engineering Rock Mass Classifications: New York: John Wiley & Sons, first edition.

Bieniawski, Z. T., 1990: Tunnel Design by Rock Mass Classifications: Washington: US Army Corps of Engineers, first edition.

BMO Capital Markets, 2020: Material Precious Metal & Minerals: September 2020.

Brady, B.H. & Brown, E.T., 2004: Rock Mechanics for Underground Mining: Kluwer Academic, third edition.

Brown, J.J., Malhotra, D., and Black, Z., 2012: NI 43-101 Technical Report on Resources, Grassy Mountain Gold Project, Malheur County, Oregon: report prepared by Gustavson Associates for Calico Resources Corp., effective date September 26, 2012.

Buchanan, L.J., 1981: Precious Metal Deposits Associated with Volcanic Environments in the Southwest: in Dickinson, W.R., and Payne, W.D., eds, Relations of Tectonics to Ore Deposits in the Southern Cordillera: Arizona Geological Society Digest, v. 14, pp. 237–261.

Caceres, C.A., 2011: Quantifying the Effect of Rock Mass Quality on Peak Particle Velocity for Underground Drift Development: PhD thesis, University of British Columbia.

Canadian Securities Administrators (CSA), 2011: National Instrument 43-101, Standards of Disclosure for Mineral Projects, Canadian Securities Administrators.

Cantor Fitzgerald, 2020: Precious Metals & Mining Macro: March 2020.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 325 May 27, 2026

Carter, T. G.,2000: An Update on the Scaled Span Concept for Dimensioning Surface Crown Pillar for New or Abandoned Mine Workings: 4^th North American Rock Mechanics Symposium, 31 July–3 August, Seattle, Washington.

Clark, A., Thompson, J., and Scanlon, T., 2018: Grassy Mountain Pre-Feasibility Dewatering Estimates RE: (1294.0010 - Task 6): Memorandum prepared by SPF Water Engineering for Paramount Gold Nevada, January 2018, 129 p.

Cordova, M., Saw, H., and Villaescusa, E., 2015: Laboratory Testing of Cemented Rock Fill for Open Stope Support.

Cummings, M.L., 1991: Relationships Among Volcaniclastic Sedimentation, Volcanism, Faulting, and Hydrothermal Activity West of Lake Owyhee, Malheur County, Oregon: in Geology and Ore Deposits of the Great Basin: Geological Society of Nevada, Symposium Proceedings, v2, pp. 111–132.

Erwin, T.P., 2017: Mineral Status Report for the Grassy Mountain Project: Report prepared for Paramount Gold Nevada Corp. by Erwin & Thompson, LLP, Reno, Nevada, 23 p.

Fashing, F. and Vanek, R., 2011: Engineering Geological Characterisation of Fault Rocks and Fault Zones: Geomechanics and Tunnelling, 4(3), pp. 181–194.

French, G.M., 1998: Possible Differences Between Tombstone and the Atlas and Newmont Drilling: internal Atlas Precious Metals report, in Tombstone Exploration memorandum, 1 p.

Golden Sunlight Mines, 1991: Grassy Mountain Metallurgical Studies: May 1991.

Golder, 2016a: Collection of Geotechnical Data from Drill Core at Grassy Mountain: Field procedure manual, Lake Oswego, Oregon prepared by Golder Associates.

Golder, 2016b: Grassy Mountain Project – Tailings Storage Facility, Siting and Trade-Off Study, Malheur County, Oregon: Report prepared for Paramount Nevada by Golder Associates Inc. December 9, 2016.

Golder, 2018a: Paramount Gold Nevada – Grassy Mountain Project, Geotechnical Data Collection Factual Report: Report prepared for Paramount Gold Nevada Corp. by Golder Associates Inc., March 2018, 281 p.

Golder, 2018b. Report Pre-Feasibility Design Tailings Storage Facility Grassy Mountain Project: Report prepared by Golder Associates Inc., June 29, 2018, 1633241.36.R.REV0.

Golder, 2019a: Grassy Mountain Project – Hydrology and Stormwater Diversion Recommendations for the Process and Portal Pads. Technical memorandum prepared for Ausenco Minerals and Metals by Golder Associates Inc. Draft, June 7, 2019.

Golder, 2019b: Grassy Mountain Project – Tailings Storage Facility, Tailings Storage Facility Location Options Analysis. Prepared for Calico Resources USA Corp. by Golder Associates Inc. September 13, 2019.

Golder, 2019c: Detailed Design, Tailings Storage Facility and Waste Rock Dump, Grassy Mountain Mine, Malheur County, Oregon: Report prepared for Calico Resources USA Corp. by Golder Associates Inc., November 6, 2019.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 326 May 27, 2026

Golder, 2019d: Stormwater Pollution Control Plan, Grassy Mountain Mine, Malheur County, Oregon. Prepared for Calico Resources USA Corp. by Golder Associates inc. November 6, 2019.

Golder, 2020: Rock Mechanics Laboratory Testing Results (Grassy Mountain Project), Reno, Nevada.

Golder, 2021a: Stormwater Pollution Control Plan, Grassy Mountain Mine, Malheur County, Oregon, Revision 1. Prepared for Calico Resources USA Corp. by Golder Associates USA Inc. October 27, 2021.

Golder, 2021b: Abbreviated Operating Permit Application – Grassy Mountain Basalt Borrow Quarry, Revision 1. Prepared for Oregon Department of Geology and Minerals Industries by Golder Associates USA Inc. October 27, 2021.

Golder, 2021c: Abbreviated Operating Permit Application – Grassy Mountain Closure Cover Borrow Areas Quarry. Prepared for Oregon Department of Geology and Minerals Industries by Golder Associates USA Inc. October 27, 2021.

Golder, 2021d: Detailed Design, Tailings Storage Facility and Temporary Waste Rock Storage Facility, Grassy Mountain Mine, Malheur County, Oregon, Revision 1. Report prepared for Calico Resources USA Corp. by Golder Associates USA Inc., October 29, 2021.

Gonzalez de Vallejo, L., 2004: Ingeniería Geológica: Pearson Educación, Madrid.

Gonzalez de Vallejo, L., Ferrer, M., Ortuño, L., Oteo, C., 2002: Ingeniería Geológica, Madrid, España.

Goodman, R., 1989: Introduction to Rock Mechanics: John Wiley & Sons, New York, second edition.

Gustin, M.M., Dyer, T.L., MacMahon, C., Caro, B., Raponi, T.R., and Baldwin, D., 2018: Preliminary Feasibility Study and Technical Report for the Grassy Mountain Gold and Silver Project, Malheur County, Oregon, USA: report prepared by Mine Development Associates, Golder Associates and Ausenco Canada Inc. for Paramount Gold Nevada Corp., effective date 21 May, 2018.

Hazen Research Inc., 1990: Grassy Mountain Metallurgical Studies: March 1990.

Hazen Research Inc., 1991: Gravity Concentrations Studies on the Grassy Mountain Gold Ore, July 1991.

Hoek, E.; Kaiser, P. and Bawden, W., 1995: Support for Underground Excavations in Hard Rock: A. A. Balkema.

Hulse, D.E., Brown, J.J., and Malhotra, D., 2012: NI 43-101 Technical Report on Resources, Grassy Mountain Gold Project, Malheur County, Oregon: report prepared by Gustavson Associates for Calico Resources Corp., effective date March 1, 2012.

Itasca, 2012: FLAC3D (Fast Lagrangian Analysis of Continua in 3 Dimensions), 2010: v5.0.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 327 May 27, 2026

Jory, J.C., 1993: Grassy Mountain Development Geology 1993 Year-End Report: internal Newmont Exploration Limited draft memorandum, December 1993, 9 p. plus figures.

Kelly, J.M., 1988: Discovery History of the Grassy Mountain Deposit: unpublished inter-office correspondence of Atlas Precious Metals Inc., September 1988, 4 p.

Laubscher D. H. and Jakubec J., 2001: The MRMR Rock Mass Classification for Jointed Rock Masses: in W. A. Hustrulid & R. L. Bullock eds. Underground Mining Methods: Engineering Fundamentals and International Case Studies. New York, Society of Mining Engineers, pp. 474–481.

Laubscher, D. H., 1990: A Geomechanics Classification System for the Rating of Rock Mass in Mine Design: Journal of the South African Institute of Mining and Metallurgy, 90(10), pp. 257–273.

Lechner, M.J., 2011: Grassy Mountain NI 43-101 Technical Report, Malheur County, Oregon: Report prepared for Calico Resources Corp., effective date June 6, 2011.

Lechner, M.J., 2007: Grassy Mountain Technical Report, Malheur County, Oregon: NI 43-101 Technical Report: Report prepared for Seabridge Gold Inc., effective date April 27, 2007

MacMahon, C., Browne, R., and Barton, M., 2018: Draft Report Pre-Feasibility Design Tailings Storage Facility Grassy Mountain Project: Report prepared by Golder Associates Inc., June 2018, 1633241.36. REVA, 30 p. plus appendices.

Mathews, 1981: Stability Graph Method: SME Mining Engineering Handbook, Third Edition, pp. 362–363.

McClelland Laboratories Inc., 2020: Report on Milling/ Cyanidation Testing – Grassy Mountain Composites MLI Job No. 4551, August 13, 2020.

MetaRock Laboratories, 2020: Rock Mechanics Testing Report for - CRF Testing. Houston, Texas.

Mitchell, R.J. and Roettger, J.J., 1989: Analysis and Modelling of Sill Pillars: in Innovations in Mining Backfill Technology, Balkema, Rotterdam, pp 53–62.

Newmont Exploration Inc., 1993: Grassy Mountain Metallurgical Test Results: December 1993.

Nicholas, D.E., 1981: Method Selection – A Numerical Approach; Design and Operation of Caving and Sublevel Stoping Mines: SME-AIME, New York.

Oregon Water Resources Department (OWRD), 2020: Grassy Mountain Tailings Dam. Approval letter prepared by Oregon Water Resources Department, July 7, 2020.

OWRD, 2025. OWRD Tailings Dam Approval Extension Request – Grassy Mountain Mine, Malheur County. E-mail correspondence from Janicek, T. to MacMahon, C. on July 3, 2025.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 328 May 27, 2026

Palmström, A., 1995: RMi - A Rock Mass Characterization System for Rock Engineering Purposes: PhD thesis, University of Oslo.

Pakalnis, R.; Caceres, C., Clapp, K., and Morin, M., 2005: Design Spans – Underhand and Fill Mining.

Raponi T. R., Seamons J., Collyard, J. S., MacMahon C. (2022): Grassy Mountain Project: S-K 1300 Technical Report Summary on Feasibility Study, Oregon, United States. Report prepared by Ausenco Engineering Canada Inc., Arrowhead, SLR, RESPEC, GMS, and WSP for Paramount Gold Nevada Corp., effective date June 30, 2022.

Raponi T. R., Gustin M. M., Seamons J., DeLong R., MacMahon C., Palma L., 2020: Feasibility Study and Technical Report for the Grassy Mountain Project, Oregon, USA: report prepared by Mine Development Associates, Golder Associates, EM Strategies, Geotechnical Mine Solutions and Ausenco Canada Inc. for Paramount Gold Nevada Corp., effective date 15 September 2020.

Read J., and Stacey P., 2009: Guidelines for Open Pit Slope Design.

Resource Development Inc. (RDI), 2012: Review of Metallurgical Studies for the Grassy Mountain Project: January 2012.

Resource Development Inc., (RDI) 2015: Metallurgical Testing of Grassy Mountain Project, Malheur County Oregon: March 2015.

Riedmüller, G., Brosch, F. J., Klima, K. and Medley, E. W., 2001: Engineering geological Characterization of Brittle Faults and Classification of Fault Rocks: Felsbau, 19(4), pp. 13–19.

Rocscience, 2020: RS2 v10.012. 2D Finite Element Program for Rock and Soil Applications.

Rytuba, J.J., and McKee, E.H., 1984: Peralkaline Ash Flow Tuffs and Calderas of the McDermitt Volcanic Field, Southeast Oregon and North Central Nevada: Journal of Geophysical Research v. 89; doi: 10.1029/JB080i010p08616. issn: 0148-0227.

Rytuba, J.J., and VanderMuelen, D.B., 1991: Hot-Spring Precious Metal Systems in the Lake Owyhee Volcanic Field, Oregon-Idaho: in Geology and Ore Deposits of the Great Basin: Geological Society of Nevada, Symposium Proceedings, v2, pp. 1085–1096.

Saw, N., De Vries, R., Hassel, R., and Villaescusa, E., 2017: Optimization of Cemented Rockfill Strength for Open Stope Support.

SGS, 2018: An Investigation into Metallurgical Testing of samples from the Grassy Mountain Gold Project (Project 15944-001), March 2018.

SGS, 2020a: An Investigation into Comminution and Metallurgical testing on Samples from the Grassy Mountain Gold Project, Project Number 15944-02 – Final Report; June 23, 2020

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 329 May 27, 2026

SGS, 2020b: An Investigation by High-Definition Mineralogy into One Composite Sample from Grassy Mountain Mine, Project Number 15944-02 – Final Report, September 18, 2020

Siems, P.L., 1990: Grassy Mountain Alteration and Geochemistry Report: unpublished internal report prepared for Atlas Precious Metals Corporation.

Sillitoe, R.H., 1993: Epithermal Models: Genetic Types, Geometrical Controls and Shallow Features: in Kirkham, R.V., Sinclair, W.D., Thorpe, R.I., and Duke, J.M. (eds.), Mineral Deposit Modeling, Geological Association of Canada Special Paper, n. 40, pp. 403–417.

Steele, G.L., 1990: Grassy Mountain Rock Density: internal Atlas Precious Metals, Inc. memorandum, 2 p.

Szwedzicki, T., 2003: Rock Mass Behavior Prior to Failure: Int. J Rock Mech and Min Sci, (40), pp. 573–584.

Villaescusa, E., 2014: Geotechnical Design for Sublevel Open Stoping.

Weiss, S.I., 2017: Summary Report on Drilling Targets for Augmenting Mill Feed, Grassy Mountain Gold Project, Malhuer County, Oregon: unpublished report prepared for Paramount Gold Nevada Corp., June 2020, 20 p.

Werkman, D., 2026: Financial Model Rev A MNP Tax Edit: model prepared by MNP for Paramount Nevada Gold Corp., May 19, 2026.

Wilson, S.E., Pennstrom, W.J. Jr., Batman, S.B., and Black, Z.J., 2015: Amended Preliminary Economic Assessment, Calico Resources Corp., Grassy Mountain Project, Malheur County, Oregon, USA: report prepared by Metal Mining Consultants Inc. for Calico Resources Corp., effective date 13 January 2015, amended July 9, 2015.

Wright, J.L., 2012: Grassy Mountain Property CSAMT Survey GIS Compilation: unpublished report prepared for Calico Resources Corp., February 2012, 48 p., plus data files on CD.

WSP 2025: Tailings Storage Facility Dam Safety Permit Extension Request, Grassy Mountain project, Malheur County, Oregon. Letter prepared by WSP USA Inc. for Oregon Water Resources Department, July 3, 2025.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 330 May 27, 2026

25 RELIANCE ON INFORMATION PROVIDED BY THE REGISTRAR

25.1 Introduction

The QPs have relied upon the following other expert reports, which provided information regarding mineral rights, surface rights, property agreements, water rights, royalties, environmental, permitting, social license, closure, taxation and marketing for sections of this Report.

25.2 Property Agreements, Mineral Tenure, Surface Rights and Royalties

The QPs have not independently reviewed ownership of the Project area and any underlying property agreements, mineral tenure, surface rights, or royalties. The QPs have fully relied upon information derived from Paramount and legal experts retained by Paramount for this information through the following documents:

• Erwin, T.P., 2017: Mineral Status Report: report prepared by Erwin, Thompson & Faillers LLP for Paramount Nevada Gold Corp., September 26, 2017, 9 p. plus appendices

The information relied upon falls under the category “Legal matters” under § 229.1302(f).

This information is used to present the executive summary in Section 1 and the interpretation and conclusions in Section 22. This information is used in discussing property ownership information in Section 3 of the Report, the tailings facility design in Section 15, the permitting and closure discussions in Section 17, and in support of the economic analysis in Section 19. It also supports the Mineral Resource estimate in Section 11 and the Mineral Reserve estimate in Section 12.

25.3 Environmental, Permitting, Closure, and Social and Community Impact

The QPs have fully relied upon information supplied by Paramount and experts retained by Paramount for information related to design reports, baseline and supporting studies for environmental permitting, environmental permitting and monitoring requirements, environmental characterization reports, ability to maintain and renew permits, emissions controls, closure planning, closure and reclamation bonding and bonding requirements, sustainability accommodations.

The information relied upon falls within the categories “Environmental matters” and “Accommodations the registrant commits or plans to provide to local individuals or groups in connection with its mine plans” under § 229.1302(f).

This information is used in the executive summary in Section 1 and when discussing the property ownership information in Section 3. It is also used when discussing the permitting, closure plan and RCE in Section 17, and the economic analysis in Section 19. It supports the Mineral Resource estimate in Section 11 and the Mineral Reserve estimate in Section 12.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 331 May 27, 2026

25.4 Taxation

The QPs have fully relied upon information supplied by experts retained by Paramount for information related to taxation as applied to the financial model as follows:

• Werkman, D., 2026: Financial Model Rev A MNP Tax Edit: model prepared by MNP for Paramount Nevada Gold Corp., May 19, 2026.

The information relied upon falls within the category “Governmental Factors” under § 229.1302(f).

This information is used to present the executive summary in Section 1 and the interpretation and conclusions in Section 22. This information is used in the economic analysis in Section 19 of the Report.

25.5 Markets

The QPs have not independently reviewed the marketing or contract information. The QPs have fully relied upon information derived from Paramount and experts retained by Paramount for information relating to market studies/markets for product, market entry strategies, marketing and sales contracts, product valuations, product specifications, refining and treatment charges, agency relationships, material contracts (e.g. mining, concentrating, smelting, refining, transportation, handling, sales and hedging, forward sales contracts or arrangements) and contract status (in place, renewals).

The information relied upon by the falls within the category of “Marketing Information and Plans” under § 229.1302(f).

This information is used to present the executive summary in Section 1 and the interpretation and conclusions in Section 22. This information is used when discussing the market, commodity price and contract information in Section 16, and in the economic analysis in Section 19. It supports the Mineral Resource estimate in Section 11 and the Mineral Reserve estimate in Section 12.

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 332 May 27, 2026

APPENDIX A – CLAIMS LIST

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

36-2001-0141

Poison Springs 24

84-121773

Patented

05-04-84

Calico Resources

Grassy

36-2001-0141

36-2001-0141

Poison Springs 25

84-121774

Patented

05-03-84

Calico Resources

Grassy

36-2001-0141

36-2001-0141

Poison Springs 35

84-121775

Patented

04-05-85

Calico Resources

Grassy

36-2001-0141

ORMC106700

Winter Claim 33

88-20087

LODE

08-01-88

Cryla

Grassy

ORMC155919

Winter #1

2001-1031

LODE

02/18/2001

Cryla

Grassy

ORMC155920

Winter #2

2001-1032

LODE

02/18/2001

Cryla

Grassy

ORMC155921

Winter #3

2001-1033

LODE

02/18/2001

Cryla

Grassy

ORMC155922

Winter #4

2001-1034

LODE

02/18/2001

Cryla

Grassy

ORMC155923

Winter #5

2001-1035

LODE

02/18/2001

Cryla

Grassy

ORMC155924

Winter #6

2001-1036

LODE

02/18/2001

Cryla

Grassy

ORMC155925

Winter #7

2001-1037

LODE

02/18/2001

Cryla

Grassy

ORMC155926

Winter #8

2001-1038

LODE

02/18/2001

Cryla

Grassy

ORMC158876

Cryla #1

2004-2068

LODE

03/13/2004

Cryla

Grassy

ORMC158877

Cryla #2

2004-2069

LODE

03/13/2004

Cryla

Grassy

ORMC158878

Cryla #3

2004-2070

LODE

03/13/2004

Cryla

Grassy

ORMC158879

Cryla #4

2004-2071

LODE

03/13/2004

Cryla

Grassy

ORMC158880

Cryla #5

2004-2072

LODE

03/13/2004

Cryla

Grassy

ORMC158881

Cryla #6

2004-2073

LODE

03/13/2004

Cryla

Grassy

ORMC158882

Cryla #7

2004-2074

LODE

03/13/2004

Cryla

Grassy

ORMC158883

Cryla #8

2004-2075

LODE

03/13/2004

Cryla

Grassy

ORMC164789

Lucky Lucy #1

2009-3235

LODE

04-12-09

Cryla

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 333 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC164790

Lucky Lucy #2

2009-3236

LODE

04-12-09

Cryla

Grassy

ORMC164791

Lucky Lucy #3

2009-3237

LODE

04-12-09

Cryla

Grassy

ORMC164792

Lucky Lucy #4

2009-3238

LODE

04-12-09

Cryla

Grassy

ORMC164793

Lucky Lucy #5

2009-3239

LODE

04-12-09

Cryla

Grassy

ORMC164794

Lucky Lucy #6

2009-3240

LODE

04-12-09

Cryla

Grassy

ORMC164795

Lucky Lucy #7

2009-3241

LODE

04-12-09

Cryla

Grassy

ORMC164796

Lucky Lucy #8

2009-3242

LODE

04-12-09

Cryla

Grassy

ORMC164797

Lucky Lucy #9

2009-3243

LODE

04-12-09

Cryla

Grassy

ORMC164798

Lucky Lucy #10

2009-3244

LODE

04-12-09

Cryla

Grassy

ORMC76751

Winter Claim 32

84-122580

LODE

07-10-84

Cryla

Grassy

ORMC127904

Poison Springs 16A

90-1362

LODE

01/28/1990

Calico Resources

Grassy

ORMC127905

Poison Springs 17A

90-1363

LODE

01/28/1990

Calico Resources

Grassy

ORMC174063

PSR 1

2017-2056

LODE

03/30/2017

Calico Resources

Grassy

ORMC174064

PSR 2

2017-2057

LODE

03/29/2017

Calico Resources

Grassy

ORMC174065

PSR 3

2017-2058

LODE

03/29/2017

Calico Resources

Grassy

ORMC174066

PSR 4

2017-2059

LODE

03/29/2017

Calico Resources

Grassy

ORMC174067

PSR 5

2017-2060

LODE

03/29/2017

Calico Resources

Grassy

ORMC174068

PSR 6

2017-2061

LODE

03/29/2017

Calico Resources

Grassy

ORMC74965

Poison Springs #1

84-121750

LODE

05-01-84

Calico Resources

Grassy

ORMC74966

Poison Springs #2

84-121751

LODE

05-01-84

Calico Resources

Grassy

ORMC74967

Poison Springs #3

84-121752

LODE

05-01-84

Calico Resources

Grassy

ORMC74968

Poison Springs #4

84-121753

LODE

05-01-84

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 334 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC74969

Poison Springs #5

84-121754

LODE

05-01-84

Calico Resources

Grassy

ORMC74970

Poison Springs #6

84-121755

LODE

05-01-84

Calico Resources

Grassy

ORMC74971

Poison Springs #7

84-121756

LODE

05-01-84

Calico Resources

Grassy

ORMC74972

Poison Springs #8

84-121757

LODE

05-01-84

Calico Resources

Grassy

ORMC74973

Poison Springs #9

84-121758

LODE

05-01-84

Calico Resources

Grassy

ORMC74974

Poison Springs #10

84-121759

LODE

05-01-84

Calico Resources

Grassy

ORMC74975

Poison Springs #11

84-121760

LODE

05-01-84

Calico Resources

Grassy

ORMC74976

Poison Springs #12

84-121761

LODE

05-01-84

Calico Resources

Grassy

ORMC74977

Poison Springs #13

84-121762

LODE

05-02-84

Calico Resources

Grassy

ORMC74978

Poison Springs #14

84-121763

LODE

05-02-84

Calico Resources

Grassy

ORMC74979

Poison Springs #15

84-121764

LODE

05-02-84

Calico Resources

Grassy

ORMC74980

Poison Springs #16

90-1364

LODE

05-02-84

Calico Resources

Grassy

ORMC74981

Poison Springs #17

90-1365

LODE

05-02-84

Calico Resources

Grassy

ORMC74982

Poison Springs #18

84-121767

LODE

05-03-84

Calico Resources

Grassy

ORMC74983

Poison Springs #19

90-6119

LODE

05-03-84

Calico Resources

Grassy

ORMC74984

Poison Springs #20

90-6120

LODE

05-03-84

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 335 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC74985

Poison Springs #21

90-6121

LODE

05-03-84

Calico Resources

Grassy

ORMC74986

Poison Springs #22

84-121771

LODE

05-03-84

Calico Resources

Grassy

ORMC74987

Poison Springs #23

88-22375

LODE

05-03-84

Calico Resources

Grassy

ORMC74990

Poison Springs #26

84-121775

LODE

05/25/1984

Calico Resources

Grassy

ORMC74991

Poison Springs #27

84-121776

LODE

05/24/1984

Calico Resources

Grassy

ORMC74992

Poison Springs #28

84-121777

LODE

05/24/1984

Calico Resources

Grassy

ORMC74996

Poison Springs #32

84-121781

LODE

05/25/1984

Calico Resources

Grassy

ORMC82455

Poison Springs #36

88-22384

LODE

04-05-85

Calico Resources

Grassy

ORMC82456

Poison Springs #37

90-6130

LODE

04-05-85

Calico Resources

Grassy

ORMC104797

Frog #1

88-18804

LODE

05-06-88

Calico Resources

Grassy

ORMC104798

Frog #2

88-18805

LODE

05-06-88

Calico Resources

Grassy

ORMC104801

Frog #5

88-18808

LODE

05-06-88

Calico Resources

Grassy

ORMC104803

Frog #7

88-18809

LODE

05-06-88

Calico Resources

Grassy

ORMC104805

Frog #9

88-18811

LODE

05-06-88

Calico Resources

Grassy

ORMC104807

Frog #11

88-18813

LODE

05-06-88

Calico Resources

Grassy

ORMC104812

Frog #16

88-18819

LODE

05-06-88

Calico Resources

Grassy

ORMC104814

Frog #18

88-18821

LODE

05-06-88

Calico Resources

Grassy

ORMC104815

Frog #19

88-18822

LODE

05-06-88

Calico Resources

Grassy

ORMC104816

Frog #20

88-18823

LODE

05-06-88

Calico Resources

Grassy

ORMC104817

Frog #21

88-18824

LODE

05-06-88

Calico Resources

Grassy

ORMC104818

Frog #22

88-18825

LODE

05-06-88

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 336 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC104819

Frog #23

88-18826

LODE

05-06-88

Calico Resources

Grassy

ORMC104820

Frog #24

88-18827

LODE

05-06-88

Calico Resources

Grassy

ORMC104821

Frog #25

88-18828

LODE

05-07-88

Calico Resources

Grassy

ORMC104822

Frog #26

88-18829

LODE

05-07-88

Calico Resources

Grassy

ORMC104823

Frog #27

88-18830

LODE

05-07-88

Calico Resources

Grassy

ORMC104824

Frog #28

88-18831

LODE

05-07-88

Calico Resources

Grassy

ORMC104825

Frog #29

88-18832

LODE

05-07-88

Calico Resources

Grassy

ORMC104826

Frog #30

88-18833

LODE

05-07-88

Calico Resources

Grassy

ORMC104827

Frog #31

88-18834

LODE

05-07-88

Calico Resources

Grassy

ORMC104828

Frog #32

88-18835

LODE

05-07-88

Calico Resources

Grassy

ORMC104829

Frog #33

88-18836

LODE

05-07-88

Calico Resources

Grassy

ORMC104830

Frog #34

88-18837

LODE

05-07-88

Calico Resources

Grassy

ORMC104831

Frog #35

90-3396

LODE

05-07-88

Calico Resources

Grassy

ORMC104832

Frog #36

88-18839

LODE

05-07-88

Calico Resources

Grassy

ORMC104833

Frog #37

88-18840

LODE

05-07-88

Calico Resources

Grassy

ORMC104834

Frog #38

88-18841

LODE

05-07-88

Calico Resources

Grassy

ORMC104835

Frog #39

88-18842

LODE

05-07-88

Calico Resources

Grassy

ORMC104836

Frog #40

88-18843

LODE

05-07-88

Calico Resources

Grassy

ORMC104837

Frog #41

88-18844

LODE

05-07-88

Calico Resources

Grassy

ORMC104838

Frog #42

88-18845

LODE

05-07-88

Calico Resources

Grassy

ORMC104839

Frog #46

88-18846

LODE

05-07-88

Calico Resources

Grassy

ORMC104840

Frog #47

88-18847

LODE

05-07-88

Calico Resources

Grassy

ORMC104841

Frog #48

88-18848

LODE

05-07-88

Calico Resources

Grassy

ORMC104878

Frog #85

90-1366

LODE

05-08-88

Calico Resources

Grassy

ORMC104879

Frog #86

90-1367

LODE

05-08-88

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 337 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC104880

Frog #87

90-1368

LODE

05-08-88

Calico Resources

Grassy

ORMC104881

Frog #88

90-1369

LODE

05-08-88

Calico Resources

Grassy

ORMC104882

Frog #89

90-1370

LODE

05-08-88

Calico Resources

Grassy

ORMC104883

Frog #90

90-1371

LODE

05-08-88

Calico Resources

Grassy

ORMC104884

Frog #91

90-1372

LODE

05-08-88

Calico Resources

Grassy

ORMC104885

Frog #92

90-1373

LODE

05-08-88

Calico Resources

Grassy

ORMC104886

Frog #93

88-18893

LODE

05-08-88

Calico Resources

Grassy

ORMC104887

Frog #94

88-18894

LODE

05-08-88

Calico Resources

Grassy

ORMC104889

Frog #96

88-18896

LODE

05/17/1988

Calico Resources

Grassy

ORMC104891

Frog #98

88-18898

LODE

05/17/1988

Calico Resources

Grassy

ORMC104900

Frog #107

88-18907

LODE

05/20/1988

Calico Resources

Grassy

ORMC104901

Frog #108

88-18908

LODE

05/20/1988

Calico Resources

Grassy

ORMC104902

Frog #109

88-18909

LODE

05/20/1988

Calico Resources

Grassy

ORMC104903

Frog #110

88-18910

LODE

05/20/1988

Calico Resources

Grassy

ORMC104904

Frog #111

88-18911

LODE

05/20/1988

Calico Resources

Grassy

ORMC104905

Frog #112

88-18912

LODE

05/19/1988

Calico Resources

Grassy

ORMC104906

Frog #113

88-18913

LODE

05/19/1988

Calico Resources

Grassy

ORMC104926

Frog #133

88-18933

LODE

05/20/1988

Calico Resources

Grassy

ORMC104927

Frog #134

88-18934

LODE

05/20/1988

Calico Resources

Grassy

ORMC104928

Frog #135

88-18935

LODE

05/20/1988

Calico Resources

Grassy

ORMC104929

Frog #136

88-18936

LODE

05/20/1988

Calico Resources

Grassy

ORMC104940

Frog #147

88-18947

LODE

05/22/1988

Calico Resources

Grassy

ORMC104941

Frog #148

88-18948

LODE

05/22/1988

Calico Resources

Grassy

ORMC104942

Frog #149

88-18949

LODE

05/22/1988

Calico Resources

Grassy

ORMC104943

Frog #150

88-18950

LODE

05/22/1988

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 338 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC104960

Frog #167

88-18967

LODE

05/19/1988

Calico Resources

Grassy

ORMC104961

Frog #168

88-18968

LODE

05/19/1988

Calico Resources

Grassy

ORMC104962

Frog #169

88-18969

LODE

05/19/1988

Calico Resources

Grassy

ORMC104963

Frog #170

88-18970

LODE

05/19/1988

Calico Resources

Grassy

ORMC104964

Frog #171

88-18971

LODE

05/19/1988

Calico Resources

Grassy

ORMC104965

Frog #172

88-18972

LODE

05/19/1988

Calico Resources

Grassy

ORMC104966

Frog #173

88-18973

LODE

05/19/1988

Calico Resources

Grassy

ORMC104967

Frog #174

88-18974

LODE

05/19/1988

Calico Resources

Grassy

ORMC104968

Frog #175

88-18975

LODE

05/19/1988

Calico Resources

Grassy

ORMC104969

Frog #176

88-18976

LODE

05/19/1988

Calico Resources

Grassy

ORMC104988

Frog #195

88-18995

LODE

05/22/1988

Calico Resources

Grassy

ORMC104989

Frog #196

88-18996

LODE

05/22/1988

Calico Resources

Grassy

ORMC104990

Frog #197

88-18997

LODE

05/22/1988

Calico Resources

Grassy

ORMC104991

Frog #198

88-18998

LODE

05/21/1988

Calico Resources

Grassy

ORMC105000

Frog #207

88-19007

LODE

05/29/1988

Calico Resources

Grassy

ORMC105001

Frog #208

88-19008

LODE

05/29/1988

Calico Resources

Grassy

ORMC105002

Frog #209

88-19009

LODE

05/29/1988

Calico Resources

Grassy

ORMC105003

Frog #210

88-19010

LODE

05/24/1988

Calico Resources

Grassy

ORMC105004

Frog #211

88-19011

LODE

05/27/1988

Calico Resources

Grassy

ORMC105005

Frog #212

88-19012

LODE

05/27/1988

Calico Resources

Grassy

ORMC105006

Frog #213

88-19013

LODE

05/27/1988

Calico Resources

Grassy

ORMC105007

Frog #214

88-19014

LODE

05/27/1988

Calico Resources

Grassy

ORMC105008

Frog #215

88-19015

LODE

05/27/1988

Calico Resources

Grassy

ORMC105009

Frog #216

88-19016

LODE

05/27/1988

Calico Resources

Grassy

ORMC105017

Frog #224

88-19024

LODE

05/26/1988

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 339 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC105019

Frog #226

88-19026

LODE

05/26/1988

Calico Resources

Grassy

ORMC105021

Frog #228

88-19028

LODE

05/26/1988

Calico Resources

Grassy

ORMC105023

Frog #230

88-19030

LODE

05/26/1988

Calico Resources

Grassy

ORMC105025

Frog #232

88-19032

LODE

05/26/1988

Calico Resources

Grassy

ORMC105913

Frog #252

88-19861

LODE

07/21/1988

Calico Resources

Grassy

ORMC107597

Frog #649

88-21299

LODE

08/17/1988

Calico Resources

Grassy

ORMC107598

Frog #650

88-21300

LODE

08/17/1988

Calico Resources

Grassy

ORMC107599

Frog #651

88-21301

LODE

08/17/1988

Calico Resources

Grassy

ORMC107600

Frog #652

88-21302

LODE

08/17/1988

Calico Resources

Grassy

ORMC107703

Frog #755

88-21405

LODE

08/23/1988

Calico Resources

Grassy

ORMC107704

Frog #756

88-21406

LODE

08/23/1988

Calico Resources

Grassy

ORMC108077

Don #1

88-22025

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108078

Don #2

88-22026

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108079

Don #3

88-22027

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108080

Don #4

88-22028

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108081

Don #5

88-22029

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108082

Don #6

88-22030

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108083

Don #7

88-22031

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108084

Don #8

88-22032

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108085

Don #9

88-22033

MILLSITE

09/28/1988

Calico Resources

Grassy

ORMC108086

Frog #10A

88-22228

LODE

09/28/1988

Calico Resources

Grassy

ORMC108087

Frog #25A

88-22229

LODE

09/27/1988

Calico Resources

Grassy

ORMC108088

Frog #26A

88-22230

LODE

09/27/1988

Calico Resources

Grassy

ORMC108089

Frog #35A

88-22231

LODE

09/27/1988

Calico Resources

Grassy

ORMC108090

Frog #46A

88-22232

LODE

09/27/1988

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 340 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC108091

Frog #46B

88-22233

LODE

09/27/1988

Calico Resources

Grassy

ORMC125178

Frog #151

89-38517

LODE

10-04-89

Calico Resources

Grassy

ORMC126210

Frog #3

89-39554

LODE

10/29/1989

Calico Resources

Grassy

ORMC126212

Frog #1274

89-39556

LODE

10/27/1989

Calico Resources

Grassy

ORMC126213

Frog #1275

89-39557

LODE

10/27/1989

Calico Resources

Grassy

ORMC126215

Frog #1277

89-39559

LODE

10/27/1989

Calico Resources

Grassy

ORMC146318

Poison Spring 1A

93-6060

LODE

07/19/1993

Calico Resources

Grassy

ORMC146319

Poison Spring 3A

93-6061

LODE

07/19/1993

Calico Resources

Grassy

ORMC146320

Poison Spring 5A

93-6062

LODE

07/20/1993

Calico Resources

Grassy

ORMC146321

Poison Spring 6A

93-6063

LODE

07/20/1993

Calico Resources

Grassy

ORMC146322

Poison Spring 7A

93-6064

LODE

07/18/1993

Calico Resources

Grassy

ORMC146323

Poison Spring 8A

93-6065

LODE

07/18/1993

Calico Resources

Grassy

ORMC146324

Poison Spring 9A

93-6066

LODE

07/19/1993

Calico Resources

Grassy

ORMC146325

Poison Spring 11A

93-6067

LODE

07/19/1993

Calico Resources

Grassy

ORMC146326

Poison Spring 14A

93-6068

LODE

07/18/1993

Calico Resources

Grassy

ORMC146327

Poison Spring 18A

93-6069

LODE

07/18/1993

Calico Resources

Grassy

ORMC146328

Poison Spring 22A

93-6070

LODE

07/18/1993

Calico Resources

Grassy

ORMC146329

Poison Spring 26A

93-6071

LODE

07/18/1993

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 341 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC146330

Poison Spring 27A

93-6072

LODE

07/19/1993

Calico Resources

Grassy

ORMC146331

Poison Spring 38A

93-6073

LODE

07/18/1993

Calico Resources

Grassy

ORMC167998

GM 5058

2011-3790

LODE

09/15/2011

Calico Resources

Grassy

ORMC167999

GM 5059

2011-3791

LODE

09/15/2011

Calico Resources

Grassy

ORMC168000

GM 5060

2011-3792

LODE

09/15/2011

Calico Resources

Grassy

ORMC168001

GM 5061

2011-3793

LODE

09/15/2011

Calico Resources

Grassy

ORMC168002

GM 5062

2011-3794

LODE

09/15/2011

Calico Resources

Grassy

ORMC168003

GM 5063

2011-3795

LODE

09/17/2011

Calico Resources

Grassy

ORMC168004

GM 5064

2011-3796

LODE

09/17/2011

Calico Resources

Grassy

ORMC168005

GM 5065

2011-3797

LODE

09/17/2011

Calico Resources

Grassy

ORMC168006

GM 5066

2011-3798

LODE

09/17/2011

Calico Resources

Grassy

ORMC168007

GM 5067

2011-3799

LODE

09/17/2011

Calico Resources

Grassy

ORMC168008

GM 5068

2011-3800

LODE

09/17/2011

Calico Resources

Grassy

ORMC168009

GM 5069

2011-3801

LODE

09/17/2011

Calico Resources

Grassy

ORMC168010

GM 5070

2011-3802

LODE

09/17/2011

Calico Resources

Grassy

ORMC168011

GM 5071

2011-3803

LODE

09/17/2011

Calico Resources

Grassy

ORMC168012

GM 5072

2011-3804

LODE

09/17/2011

Calico Resources

Grassy

ORMC168013

GM 5150

2011-3805

LODE

09/15/2011

Calico Resources

Grassy

ORMC168014

GM 5151

2011-3806

LODE

09/15/2011

Calico Resources

Grassy

ORMC168015

GM 5152

2011-3807

LODE

09/15/2011

Calico Resources

Grassy

ORMC168016

GM 5153

2011-3808

LODE

09/15/2011

Calico Resources

Grassy

ORMC168017

GM 5154

2011-3809

LODE

09/15/2011

Calico Resources

Grassy

ORMC168018

GM 5155

2011-3810

LODE

09/15/2011

Calico Resources

Grassy

ORMC168019

GM 5156

2011-3811

LODE

09/15/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 342 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168020

GM 5157

2011-3812

LODE

09/15/2011

Calico Resources

Grassy

ORMC168021

GM 5158

2011-3813

LODE

09/15/2011

Calico Resources

Grassy

ORMC168022

GM 5159

2011-3814

LODE

09/15/2011

Calico Resources

Grassy

ORMC168023

GM 5160

2011-3815

LODE

09/15/2011

Calico Resources

Grassy

ORMC168024

GM 5161

2011-3816

LODE

09/15/2011

Calico Resources

Grassy

ORMC168025

GM 5162

2011-3817

LODE

09/15/2011

Calico Resources

Grassy

ORMC168026

GM 5163

2011-3818

LODE

09/17/2011

Calico Resources

Grassy

ORMC168027

GM 5164

2011-3819

LODE

09/17/2011

Calico Resources

Grassy

ORMC168028

GM 5165

2011-3820

LODE

09/17/2011

Calico Resources

Grassy

ORMC168029

GM 5166

2011-3821

LODE

09/17/2011

Calico Resources

Grassy

ORMC168030

GM 5167

2011-3822

LODE

09/17/2011

Calico Resources

Grassy

ORMC168031

GM 5168

2011-3823

LODE

09/17/2011

Calico Resources

Grassy

ORMC168032

GM 5169

2011-3824

LODE

09/17/2011

Calico Resources

Grassy

ORMC168033

GM 5170

2011-3825

LODE

09/17/2011

Calico Resources

Grassy

ORMC168034

GM 5171

2011-3826

LODE

09/17/2011

Calico Resources

Grassy

ORMC168035

GM 5172

2011-3827

LODE

09/17/2011

Calico Resources

Grassy

ORMC168036

GM 5250

2011-3828

LODE

09/15/2011

Calico Resources

Grassy

ORMC168037

GM 5251

2011-3829

LODE

09/15/2011

Calico Resources

Grassy

ORMC168038

GM 5252

2011-3830

LODE

09/15/2011

Calico Resources

Grassy

ORMC168039

GM 5253

2011-3831

LODE

09/15/2011

Calico Resources

Grassy

ORMC168040

GM 5254

2011-3832

LODE

09/15/2011

Calico Resources

Grassy

ORMC168041

GM 5255

2011-3833

LODE

09/15/2011

Calico Resources

Grassy

ORMC168042

GM 5256

2011-3834

LODE

09/15/2011

Calico Resources

Grassy

ORMC168043

GM5257

2011-3835

LODE

09/15/2011

Calico Resources

Grassy

ORMC168044

GM 5258

2011-3836

LODE

09/15/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 343 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168045

GM 5259

2011-3837

LODE

09/15/2011

Calico Resources

Grassy

ORMC168046

GM 5260

2011-3838

LODE

09/15/2011

Calico Resources

Grassy

ORMC168047

GM 5261

2011-3839

LODE

09/16/2011

Calico Resources

Grassy

ORMC168048

GM 5262

2011-3840

LODE

09/16/2011

Calico Resources

Grassy

ORMC168049

GM 5263

2011-3841

LODE

09/16/2011

Calico Resources

Grassy

ORMC168050

GM 5264

2011-3842

LODE

09/16/2011

Calico Resources

Grassy

ORMC168051

GM 5265

2011-3843

LODE

09/16/2011

Calico Resources

Grassy

ORMC168052

GM 5266

2011-3844

LODE

09/16/2011

Calico Resources

Grassy

ORMC168053

GM 5267

2011-3845

LODE

09/23/2011

Calico Resources

Grassy

ORMC168054

GM 5268

2011-3846

LODE

09/23/2011

Calico Resources

Grassy

ORMC168055

GM 5269

2011-3847

LODE

09/23/2011

Calico Resources

Grassy

ORMC168056

GM 5270

2011-3848

LODE

09/23/2011

Calico Resources

Grassy

ORMC168057

GM 5271

2011-3849

LODE

09/23/2011

Calico Resources

Grassy

ORMC168058

GM 5272

2011-3850

LODE

09/23/2011

Calico Resources

Grassy

ORMC168059

GM 5273

2011-3851

LODE

09/23/2011

Calico Resources

Grassy

ORMC168060

GM 5274

2011-3852

LODE

09/23/2011

Calico Resources

Grassy

ORMC168061

GM 5275

2011-3853

LODE

09/23/2011

Calico Resources

Grassy

ORMC168062

GM 5276

2011-3854

LODE

09/23/2011

Calico Resources

Grassy

ORMC168063

GM 5352

2011-3855

LODE

09/15/2011

Calico Resources

Grassy

ORMC168064

GM 5353

2011-3856

LODE

09/15/2011

Calico Resources

Grassy

ORMC168065

GM 5354

2011-3857

LODE

09/15/2011

Calico Resources

Grassy

ORMC168066

GM 5355

2011-3858

LODE

09/15/2011

Calico Resources

Grassy

ORMC168067

GM 5356

2011-3859

LODE

09/15/2011

Calico Resources

Grassy

ORMC168068

GM 5357

2011-3860

LODE

09/15/2011

Calico Resources

Grassy

ORMC168069

GM 5358

2011-3861

LODE

09/15/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 344 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168070

GM 5359

2011-3862

LODE

09/15/2011

Calico Resources

Grassy

ORMC168071

GM 5360

2011-3863

LODE

09/15/2011

Calico Resources

Grassy

ORMC168072

GM 5361

2011-3864

LODE

09/16/2011

Calico Resources

Grassy

ORMC168073

GM 5362

2011-3865

LODE

09/16/2011

Calico Resources

Grassy

ORMC168074

GM 5363

2011-3866

LODE

09/16/2011

Calico Resources

Grassy

ORMC168075

GM 5364

2011-3867

LODE

09/16/2011

Calico Resources

Grassy

ORMC168076

GM 5365

2011-3868

LODE

09/16/2011

Calico Resources

Grassy

ORMC168077

GM 5366

2011-3869

LODE

09/16/2011

Calico Resources

Grassy

ORMC168078

GM 5367

2011-3870

LODE

09/23/2011

Calico Resources

Grassy

ORMC168079

GM 5368

2011-3871

LODE

09/23/2011

Calico Resources

Grassy

ORMC168080

GM 5369

2011-3872

LODE

09/23/2011

Calico Resources

Grassy

ORMC168081

GM 5370

2011-3873

LODE

09/23/2011

Calico Resources

Grassy

ORMC168082

GM 5371

2011-3874

LODE

09/23/2011

Calico Resources

Grassy

ORMC168083

GM 5372

2011-3875

LODE

09/23/2011

Calico Resources

Grassy

ORMC168084

GM 5373

2011-3876

LODE

09/23/2011

Calico Resources

Grassy

ORMC168085

GM 5374

2011-3877

LODE

09/23/2011

Calico Resources

Grassy

ORMC168086

GM 5375

2011-3878

LODE

09/23/2011

Calico Resources

Grassy

ORMC168087

GM 5376

2011-3879

LODE

09/23/2011

Calico Resources

Grassy

ORMC168088

GM 5452

2011-3880

LODE

09/19/2011

Calico Resources

Grassy

ORMC168089

GM 5453

2011-3881

LODE

09/19/2011

Calico Resources

Grassy

ORMC168090

GM 5454

2011-3882

LODE

09/19/2011

Calico Resources

Grassy

ORMC168091

GM 5455

2011-3883

LODE

09/19/2011

Calico Resources

Grassy

ORMC168092

GM 5552

2011-3884

LODE

09/19/2011

Calico Resources

Grassy

ORMC168093

GM 5553

2011-3885

LODE

09/19/2011

Calico Resources

Grassy

ORMC168094

GM 5554

2011-3886

LODE

09/19/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 345 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168095

GM 5555

2011-3887

LODE

09/19/2011

Calico Resources

Grassy

ORMC168096

GM 5580

2011-3888

LODE

09/23/2011

Calico Resources

Grassy

ORMC168097

GM 5581

2011-3889

LODE

09/23/2011

Calico Resources

Grassy

ORMC168098

GM 5582

2011-3890

LODE

09/23/2011

Calico Resources

Grassy

ORMC168099

GM 5583

2011-3891

LODE

09/23/2011

Calico Resources

Grassy

ORMC168100

GM 5584

2011-3892

LODE

09/23/2011

Calico Resources

Grassy

ORMC168101

GM 5652

2011-3893

LODE

09/18/2011

Calico Resources

Grassy

ORMC168102

GM 5653

2011-3894

LODE

09/18/2011

Calico Resources

Grassy

ORMC168103

GM 5654

2011-3895

LODE

09/18/2011

Calico Resources

Grassy

ORMC168104

GM 5655

2011-3896

LODE

09/18/2011

Calico Resources

Grassy

ORMC168105

GM 5680

2011-3897

LODE

09/22/2011

Calico Resources

Grassy

ORMC168106

GM 5681

2011-3898

LODE

09/22/2011

Calico Resources

Grassy

ORMC168107

GM 5682

2011-3899

LODE

09/22/2011

Calico Resources

Grassy

ORMC168108

GM 5683

2011-3900

LODE

09/22/2011

Calico Resources

Grassy

ORMC168109

GM 5684

2011-3901

LODE

09/22/2011

Calico Resources

Grassy

ORMC168110

GM 5752

2011-3902

LODE

09/18/2011

Calico Resources

Grassy

ORMC168111

GM 5753

2011-3903

LODE

09/18/2011

Calico Resources

Grassy

ORMC168112

GM 5754

2011-3904

LODE

09/18/2011

Calico Resources

Grassy

ORMC168113

GM 5755

2011-3905

LODE

09/18/2011

Calico Resources

Grassy

ORMC168114

GM 5756

2011-3906

LODE

09/25/2011

Calico Resources

Grassy

ORMC168115

GM 5757

2011-3907

LODE

09/25/2011

Calico Resources

Grassy

ORMC168116

GM 5758

2011-3908

LODE

09/25/2011

Calico Resources

Grassy

ORMC168117

GM 5780

2011-3909

LODE

09/22/2011

Calico Resources

Grassy

ORMC168118

GM 5781

2011-3910

LODE

09/22/2011

Calico Resources

Grassy

ORMC168119

GM 5782

2011-3911

LODE

09/22/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 346 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168120

GM 5783

2011-3912

LODE

09/22/2011

Calico Resources

Grassy

ORMC168121

GM 5784

2011-3913

LODE

09/22/2011

Calico Resources

Grassy

ORMC168122

GM 5785

2011-3914

LODE

09/22/2011

Calico Resources

Grassy

ORMC168123

GM 5786

2011-3915

LODE

09/22/2011

Calico Resources

Grassy

ORMC168124

GM 5787

2011-3916

LODE

09/22/2011

Calico Resources

Grassy

ORMC168125

GM 5852

2011-3917

LODE

09/24/2011

Calico Resources

Grassy

ORMC168126

GM 5853

2011-3918

LODE

09/24/2011

Calico Resources

Grassy

ORMC168127

GM 5854

2011-3919

LODE

09/24/2011

Calico Resources

Grassy

ORMC168128

GM 5855

2011-3920

LODE

09/24/2011

Calico Resources

Grassy

ORMC168129

GM 5856

2011-3921

LODE

09/24/2011

Calico Resources

Grassy

ORMC168130

GM 5857

2011-3922

LODE

09/24/2011

Calico Resources

Grassy

ORMC168131

GM 5858

2011-3923

LODE

09/24/2011

Calico Resources

Grassy

ORMC168132

GM 5859

2011-3924

LODE

09/24/2011

Calico Resources

Grassy

ORMC168133

GM 5860

2011-3925

LODE

09/24/2011

Calico Resources

Grassy

ORMC168134

GM 5861

2011-3926

LODE

09/24/2011

Calico Resources

Grassy

ORMC168135

GM 5862

2011-3927

LODE

09/24/2011

Calico Resources

Grassy

ORMC168136

GM 5863

2011-3928

LODE

09/24/2011

Calico Resources

Grassy

ORMC168137

GM 5864

2011-3929

LODE

09/24/2011

Calico Resources

Grassy

ORMC168138

GM 5885

2011-3930

LODE

09/22/2011

Calico Resources

Grassy

ORMC168139

GM 5886

2011-3931

LODE

09/22/2011

Calico Resources

Grassy

ORMC168140

GM 5887

2011-3932

LODE

09/22/2011

Calico Resources

Grassy

ORMC168141

GM 5956

2011-3933

LODE

09/24/2011

Calico Resources

Grassy

ORMC168142

GM 5957

2011-3934

LODE

09/24/2011

Calico Resources

Grassy

ORMC168143

GM 5958

2011-3935

LODE

09/24/2011

Calico Resources

Grassy

ORMC168144

GM 5959

2011-3936

LODE

09/24/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 347 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168145

GM 5960

2011-3937

LODE

09/24/2011

Calico Resources

Grassy

ORMC168146

GM 5961

2011-3938

LODE

09/24/2011

Calico Resources

Grassy

ORMC168147

GM 5962

2011-3939

LODE

09/24/2011

Calico Resources

Grassy

ORMC168148

GM 5974

2011-3940

LODE

09/21/2011

Calico Resources

Grassy

ORMC168149

GM 5975

2011-3941

LODE

09/21/2011

Calico Resources

Grassy

ORMC168150

GM 5976

2011-3942

LODE

09/21/2011

Calico Resources

Grassy

ORMC168151

GM 5985

2011-3943

LODE

09/22/2011

Calico Resources

Grassy

ORMC168152

GM 5986

2011-3944

LODE

09/22/2011

Calico Resources

Grassy

ORMC168153

GM 5987

2011-3945

LODE

09/22/2011

Calico Resources

Grassy

ORMC168154

GM 6056

2011-3946

LODE

09/24/2011

Calico Resources

Grassy

ORMC168155

GM 6057

2011-3947

LODE

09/24/2011

Calico Resources

Grassy

ORMC168156

GM 6058

2011-3948

LODE

09/24/2011

Calico Resources

Grassy

ORMC168157

GM 6059

2011-3949

LODE

09/24/2011

Calico Resources

Grassy

ORMC168158

GM 6060

2011-3950

LODE

09/24/2011

Calico Resources

Grassy

ORMC168159

GM 6061

2011-3951

LODE

09/24/2011

Calico Resources

Grassy

ORMC168160

GM 6062

2011-3952

LODE

09/24/2011

Calico Resources

Grassy

ORMC168161

GM 6069

2011-3953

LODE

09/21/2011

Calico Resources

Grassy

ORMC168162

GM 6070

2011-3954

LODE

09/21/2011

Calico Resources

Grassy

ORMC168163

GM 6071

2011-3955

LODE

09/21/2011

Calico Resources

Grassy

ORMC168164

GM 6072

2011-3956

LODE

09/21/2011

Calico Resources

Grassy

ORMC168165

GM 6073

2011-3957

LODE

09/21/2011

Calico Resources

Grassy

ORMC168166

GM 6074

2011-3958

LODE

09/21/2011

Calico Resources

Grassy

ORMC168167

GM 6075

2011-3959

LODE

09/21/2011

Calico Resources

Grassy

ORMC168168

GM 6076

2011-3960

LODE

09/21/2011

Calico Resources

Grassy

ORMC168169

GM 6077

2011-3961

LODE

09/21/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 348 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168170

GM 6085

2011-3962

LODE

09/21/2011

Calico Resources

Grassy

ORMC168171

GM 6086

2011-3963

LODE

09/21/2011

Calico Resources

Grassy

ORMC168172

GM 6087

2011-3964

LODE

09/21/2011

Calico Resources

Grassy

ORMC168173

GM 6156

2011-3965

LODE

09/24/2011

Calico Resources

Grassy

ORMC168174

GM 6157

2011-3966

LODE

09/24/2011

Calico Resources

Grassy

ORMC168175

GM 6158

2011-3967

LODE

09/24/2011

Calico Resources

Grassy

ORMC168176

GM 6159

2011-3968

LODE

09/24/2011

Calico Resources

Grassy

ORMC168177

GM 6160

2011-3969

LODE

09/24/2011

Calico Resources

Grassy

ORMC168178

GM 6161

2011-3970

LODE

09/24/2011

Calico Resources

Grassy

ORMC168179

GM 6162

2011-3971

LODE

09/24/2011

Calico Resources

Grassy

ORMC168180

GM 6174

2011-3972

LODE

09/21/2011

Calico Resources

Grassy

ORMC168181

GM 6175

2011-3973

LODE

09/21/2011

Calico Resources

Grassy

ORMC168182

GM 6176

2011-3974

LODE

09/21/2011

Calico Resources

Grassy

ORMC168183

GM 6177

2011-3975

LODE

09/21/2011

Calico Resources

Grassy

ORMC168184

GM 6178

2011-3976

LODE

09/21/2011

Calico Resources

Grassy

ORMC168185

GM 6179

2011-3977

LODE

09/21/2011

Calico Resources

Grassy

ORMC168186

GM 6180

2011-3978

LODE

09/21/2011

Calico Resources

Grassy

ORMC168187

GM 6181

2011-3979

LODE

09/21/2011

Calico Resources

Grassy

ORMC168188

GM 6182

2011-3980

LODE

09/21/2011

Calico Resources

Grassy

ORMC168189

GM 6183

2011-3981

LODE

09/21/2011

Calico Resources

Grassy

ORMC168190

GM 6184

2011-3982

LODE

09/21/2011

Calico Resources

Grassy

ORMC168191

GM 6185

2011-3983

LODE

09/21/2011

Calico Resources

Grassy

ORMC168192

GM 6186

2011-3984

LODE

09/21/2011

Calico Resources

Grassy

ORMC168193

GM 6187

2011-3985

LODE

09/21/2011

Calico Resources

Grassy

ORMC168194

GM 6258

2011-3986

LODE

09/21/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 349 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168195

GM 6259

2011-3987

LODE

09/21/2011

Calico Resources

Grassy

ORMC168196

GM 6260

2011-3988

LODE

09/21/2011

Calico Resources

Grassy

ORMC168197

GM 6261

2011-3989

LODE

09/21/2011

Calico Resources

Grassy

ORMC168198

GM 6262

2011-3990

LODE

09/21/2011

Calico Resources

Grassy

ORMC168199

GM 6263

2011-3991

LODE

09/21/2011

Calico Resources

Grassy

ORMC168200

GM 6264

2011-3992

LODE

09/21/2011

Calico Resources

Grassy

ORMC168201

GM 6265

2011-3993

LODE

09/21/2011

Calico Resources

Grassy

ORMC168202

GM 6266

2011-3994

LODE

09/21/2011

Calico Resources

Grassy

ORMC168203

GM 6267

2011-3995

LODE

09/21/2011

Calico Resources

Grassy

ORMC168204

GM 6268

2011-3996

LODE

09/21/2011

Calico Resources

Grassy

ORMC168205

GM 6271

2011-3997

LODE

09/20/2011

Calico Resources

Grassy

ORMC168206

GM 6272

2011-3998

LODE

09/20/2011

Calico Resources

Grassy

ORMC168207

GM 6273

2011-3999

LODE

09/20/2011

Calico Resources

Grassy

ORMC168208

GM 6274

2011-4000

LODE

09/20/2011

Calico Resources

Grassy

ORMC168209

GM 6275

2011-4001

LODE

09/20/2011

Calico Resources

Grassy

ORMC168210

GM 6276

2011-4002

LODE

09/20/2011

Calico Resources

Grassy

ORMC168211

GM 6277

2011-4003

LODE

09/20/2011

Calico Resources

Grassy

ORMC168212

GM 6278

2011-4004

LODE

09/20/2011

Calico Resources

Grassy

ORMC168213

GM 6279

2011-4005

LODE

09/20/2011

Calico Resources

Grassy

ORMC168214

GM 6280

2011-4006

LODE

09/20/2011

Calico Resources

Grassy

ORMC168215

GM 6281

2011-4007

LODE

09/22/2011

Calico Resources

Grassy

ORMC168216

GM 6282

2011-4008

LODE

09/22/2011

Calico Resources

Grassy

ORMC168217

GM 6283

2011-4009

LODE

09/22/2011

Calico Resources

Grassy

ORMC168218

GM 6284

2011-4010

LODE

09/22/2011

Calico Resources

Grassy

ORMC168219

GM 6285

2011-4011

LODE

09/22/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 350 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168220

GM 6286

2011-4012

LODE

09/22/2011

Calico Resources

Grassy

ORMC168221

GM 6287

2011-4013

LODE

09/22/2011

Calico Resources

Grassy

ORMC168222

GM 6358

2011-4014

LODE

09/21/2011

Calico Resources

Grassy

ORMC168223

GM 6359

2011-4015

LODE

09/21/2011

Calico Resources

Grassy

ORMC168224

GM 6360

2011-4016

LODE

09/21/2011

Calico Resources

Grassy

ORMC168225

GM 6361

2011-4017

LODE

09/21/2011

Calico Resources

Grassy

ORMC168226

GM 6362

2011-4018

LODE

09/21/2011

Calico Resources

Grassy

ORMC168227

GM 6363

2011-4019

LODE

09/21/2011

Calico Resources

Grassy

ORMC168228

GM 6364

2011-4020

LODE

09/21/2011

Calico Resources

Grassy

ORMC168229

GM 6365

2011-4021

LODE

09/21/2011

Calico Resources

Grassy

ORMC168230

GM 6366

2011-4022

LODE

09/21/2011

Calico Resources

Grassy

ORMC168231

GM 6367

2011-4023

LODE

09/21/2011

Calico Resources

Grassy

ORMC168232

GM 6368

2011-4024

LODE

09/21/2011

Calico Resources

Grassy

ORMC168233

GM 6371

2011-4025

LODE

09/20/2011

Calico Resources

Grassy

ORMC168234

GM 6372

2011-4026

LODE

09/20/2011

Calico Resources

Grassy

ORMC168235

GM 6373

2011-4027

LODE

09/20/2011

Calico Resources

Grassy

ORMC168236

GM 6374

2011-4028

LODE

09/20/2011

Calico Resources

Grassy

ORMC168237

GM 6375

2011-4029

LODE

09/20/2011

Calico Resources

Grassy

ORMC168238

GM 6376

2011-4030

LODE

09/20/2011

Calico Resources

Grassy

ORMC168239

GM 6377

2011-4031

LODE

09/20/2011

Calico Resources

Grassy

ORMC168240

GM 6378

2011-4032

LODE

09/20/2011

Calico Resources

Grassy

ORMC168241

GM 6379

2011-4033

LODE

09/20/2011

Calico Resources

Grassy

ORMC168242

GM 6380

2011-4034

LODE

09/20/2011

Calico Resources

Grassy

ORMC168243

GM 6381

2011-4035

LODE

09/22/2011

Calico Resources

Grassy

ORMC168244

GM 6382

2011-4036

LODE

09/22/2011

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 351 May 27, 2026

Serial Number

Claim Name

County Number

Case Type

Location Date

Owner

Claims Group

Patent Number

ORMC168245

GM 6383

2011-4037

LODE

09/22/2011

Calico Resources

Grassy

ORMC168246

GM 6384

2011-4038

LODE

09/22/2011

Calico Resources

Grassy

ORMC168247

GM 6385

2011-4039

LODE

09/22/2011

Calico Resources

Grassy

ORMC168248

GM 6386

2011-4040

LODE

09/22/2011

Calico Resources

Grassy

ORMC168249

GM 6387

2011-4041

LODE

09/22/2011

Calico Resources

Grassy

ORMC174048

PGM 1

2017-2062

LODE

03/29/2017

Calico Resources

Grassy

ORMC174049

PGM 2

2017-2063

LODE

03/29/2017

Calico Resources

Grassy

ORMC174050

PGM 3

2017-2064

LODE

03/31/2017

Calico Resources

Grassy

ORMC174051

PGM 4

2017-2065

LODE

03/30/2017

Calico Resources

Grassy

ORMC174052

PGM 5

2017-2066

LODE

03/30/2017

Calico Resources

Grassy

ORMC174053

PGM 6

2017-2067

LODE

03/31/2017

Calico Resources

Grassy

ORMC174054

PGM 7

2017-2068

LODE

03/31/2017

Calico Resources

Grassy

ORMC174055

PGM 8

2017-2069

LODE

03/31/2017

Calico Resources

Grassy

ORMC174056

PGM 9

2017-2070

LODE

03/31/2017

Calico Resources

Grassy

ORMC174057

PGM 10

2017-2071

LODE

03/30/2017

Calico Resources

Grassy

ORMC174058

PGM 11

2017-2072

LODE

03/29/2017

Calico Resources

Grassy

ORMC174059

PGM 12

2017-2073

LODE

03/29/2017

Calico Resources

Grassy

ORMC174060

PGM 13

2017-2074

LODE

03/29/2017

Calico Resources

Grassy

ORMC174061

PGM 14

2017-2075

LODE

03/29/2017

Calico Resources

Grassy

ORMC174062

PGM 15

2017-2076

LODE

03/29/2017

Calico Resources

Grassy

Grassy Mountain Project S - K 1300 Technical Summary and Feasibility Report Page 352 May 27, 2026

Filing Exhibits & Attachments

9 documents

Press Releases

• EX-99.1 EX-99.1 4.2 MB

Financial & Certifications

• EX-23.1 EX-23.1 6.4 KB
• EX-23.2 EX-23.2 6.8 KB
• EX-23.3 EX-23.3 6.1 KB
• EX-23.4 EX-23.4 6.3 KB
• EX-23.5 EX-23.5 6.4 KB

Other Documents

• EX-101 XBRL TAXONOMY EXTENSION SCHEMA 3.1 KB
• EX-101 XBRL TAXONOMY EXTENSION LABEL LINKBASE 16.8 KB
• EX-101 XBRL TAXONOMY EXTENSION PRESENTATION LINKBASE 10.6 KB