Ridgeline Minerals Reports Additional Assays for the Chinchilla Sulfide CRD Discovery at the Selena Project, Nevada

Rhea-AI Summary

Ridgeline Minerals (OTCQB: RDGMF) reported additional assays from discovery drillhole SE25-053 at the Selena project, Nevada, announcing multiple stacked CRD sulfide horizons.

Highlights include a 8.7m interval grading 175.5 g/t AgEq from 1,069m, a 1.1m sample grading 27.0% Zn (766.4 g/t AgEq) at 943m, and 17.4m at 6.0% Zn (219.9 g/t AgEq). SE25-054 is a ~700m step-out in progress and assay results will be released in 2026. The project is under a Phase 1 earn-in where South32 may earn an initial 60% (US$10M spend) and up to 80% with a further US$10M (US$20M total).

Positive

• 8.7m @ 175.5 g/t AgEq from 1,069m
• 1.1m sample @ 27.0% Zn (766.4 g/t AgEq) from 943m
• 17.4m interval @ 6.0% Zn (219.9 g/t AgEq)
• Stacked high-grade sulfide horizons in single hole (cumulative 27.2m)

Negative

• Key high-grade intercepts begin at depths > 900m downhole
• True thickness unknown for the 1.1m 27.0% Zn sample
• South32 may earn up to 80% of the project by funding US$20M, which could significantly reduce Ridgeline ownership

Vancouver, British Columbia--(Newsfile Corp. - December 18, 2025) - Ridgeline Minerals Corp. (TSXV: RDG) (OTCQB: RDGMF) (FSE: 0GC0) ("Ridgeline" or the "Company") is pleased to announce additional assay results for discovery drillhole SE25-053 at the Selena project ("Selena" or "Project") in Nevada. The lower sulfide horizon was intersected 94 meters beneath the previously announced upper zone discovery and returned a highlight intercept of 8.7 meters ("m") grading 175.5 g/t silver equivalent ("AgEq") or 7.3% zinc equivalent ("ZnEq") starting at 1,069m downhole (Figure 1 & Picture 1).

Chad Peters, Ridgeline's President, CEO & Director commented, "Discovery hole SE25-053 has exceeded our expectations for a maiden drill program, intersecting three high-grade CRD horizons with a cumulative mineralized thickness of 27.2 meters. We are especially encouraged to have hit multiple stacked sulfide lenses in a single hole, which show evidence of base metal zoning and further support our interpretation that Selena hosts a multi-phase CRD system with significant growth potential."

Mr. Peters continues "We are still in the early days of a new discovery but with individual samples grading up to 27% zinc and 379 g/t silver, we believe Selena has the potential to deliver even higher grades as we continue to vector into the core of the CRD system. Follow up drillhole SE25-054 is in progress with assay results to be released as they are received in 2026."

SE25-053 Highlights

• 1.1m grading 27.0% Zn, 60.1 g/t Ag, 0.7% Pb, 1.5 g/t Au, 0.4% Cu, 0.03% Sb (766.4 g/t AgEq or 31.9% ZnEq) starting at 943m downhole, true thickness unknown (Figure 2)
• And: 17.4 meters grading 6.0% Zn, 35.6 g/t Ag, 0.5% Pb, 0.2 g/t Au, 0.1% Cu, 0.1% Sb (219.9 g/t AgEq or 9.2% ZnEq) (Figure 2 & Picture 2)
  • Including: 8.6 meters grading 10.4% Zn, 21.1 g/t Ag, 0.3% Pb, 0.1 g/t Au, 0.1% Cu, 0.1% Sb (273.6 g/t AgEq or 11.4% ZnEq) (see November 4, 2025 press release HERE) (Table 1)

And: 8.7 meters grading 7.0% Zn, 13.9 g/t Ag, 0.3% Pb, 0.1 g/t Au, 0.1% Cu, 0.01% Sb (175.5 g/t AgEq or 7.3% ZnEq) (Picture 1)

Picture 1: Representative core photos of the 8.7m thick "lower" sulfide zone in SE25-053

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7298/278452_0033246494762901_001full.jpg

Drillhole SE25-053 is the second of the Company's three-hole maiden drill program testing the Chinchilla Sulfide target and represents a new CRD discovery. Hole SE25-054 is in progress and represents a roughly 700m step-out to the northeast of hole SE25-053 to test the extension of the same kilometer-scale MT conductive anomaly (Figure 1).

Picture 2: Representative core photos of the 17.4m thick "Upper" sulfide zone in SE25-053

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7298/278452_0033246494762901_002full.jpg

Figure 1: Plan view map showing the Chinchilla Sulfide CRD discovery in hole SE25-053 at the southern end of a kilometer-scale MT anomaly (coloured contours) that outlines the Chinchilla Sulfide target

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7298/278452_0033246494762901_003full.jpg

Table 1: Table of significant drill assays for SE25-052A and SE25-053

For a collar table click HERE and for a complete table of Selena assay results click HERE

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7298/278452_table.jpg

Figure 2: Simplified Long-Section A-A' showing the high-grade SE25-053 discovery

click HERE to view simplified X-Section B-B' looking east

To view an enhanced version of this graphic, please visit:
https://images.newsfilecorp.com/files/7298/278452_0033246494762901_005full.jpg

The Project is currently operated by Ridgeline under Phase 1 of an earn-in agreement with a wholly owned subsidiary of South32 Limited ("South32"), where South32 may earn up to an 80% interest in the Project by satisfying all commitments under the earn-in agreement (see August 22, 2024 news release HERE).

Earn-In Terms – South32 retains the right to earn an initial 60% interest in the Selena project (see August 22, 2024, press release HERE) by funding a minimum of US$10 million in qualifying work expenditures on the Project over an initial five-year term, following which South32 will have a further option to increase its interest in the Project to a total of 80% by funding an additional US$10 million in qualifying work expenditures (for an aggregate spend of US$20 million) over an additional three-year term. If South32 wishes to exercise the Phase 2 option, it must arrange for and provide draft definitive documentation in respect of a debt facility from which (if executed) Ridgeline may draw on to sufficiently fund Ridgeline's share of costs (20% pro-rata) associated with development of a mine at Selena through to commercial production.

QA/QC Procedures
Samples are submitted to American Assay Laboratories (AAL) of Sparks, Nevada, which is a certified and accredited laboratory, independent of the Company. Independent check samples are shipped to Paragon Geochemical Labs (PAL) of Sparks, Nevada. Samples are prepared using industry-standard prep methods and analysed using FA-PB30-ICP (Au; 30g fire assay) and ICP-5AM48 (48 element Suite; 0.5g 5-acid digestion/ICP-MS) methods. AAL also undertakes its own internal coarse and pulp duplicate analysis to ensure proper sample preparation and equipment calibration. Ridgeline's QA/QC program includes regular insertion of CRM standards, duplicates, and blanks into the sample stream with a stringent review of all results completed by the Company's Qualified Person, Michael T. Harp, Vice President, Exploration.

The technical information contained in this news release has been prepared under the supervision of, and approved by Michael T. Harp, CPG, the Company's Vice President, Exploration. Mr. Harp is a "qualified person" as defined under National Instrument 43-101 – Standards of Disclosure for Mineral Projects.

Selena Project
Selena is located in White Pine County, Nevada, approximately 64 kilometers ("km") north of the town of Ely, NV. The Project is currently being operated by Ridgeline under Phase 1 of an earn-in agreement with a wholly owned subsidiary of South32 Limited ("South32") and shares a property boundary with the Butte Valley project, a $33M earn-in agreement between Freeport-McMoRan and the underlying owner, Falcon Butte Minerals. The Project is comprised of 39 square kilometers of highly prospective exploration ground including Ridgeline's shallow-oxide Ag-Au ± Pb-Zn Chinchilla Oxide and deeper Chinchilla Sulfide discoveries. Subsequent drilling has continued to highlight the potential for high-grade CRD type mineralization (Ag-Zn-Pb-Au ± Cu-Sb-W) between Chinchilla Oxide and Freeport-McMoRan's Butte Valley Cu-Au-Ag-Zn porphyry located directly west of the property (View the Selena VRIFY Deck Here). For additional information regarding the South32 earn-in agreement terms view the August 22, 2024, news release HERE.

About Ridgeline Minerals Corp.
Ridgeline Minerals is a discovery focused precious and base metal explorer with a proven management team and a 200 km² exploration portfolio across seven projects in Nevada, USA. The Company is a hybrid explorer with a mix of 100%-owned exploration assets (Big Blue, Atlas, Bell Creek & Coyote) as well as two earn-in exploration agreements with Nevada Gold Mines at its Swift and Black Ridge projects and a third earn-in with South32 at its Selena project. More information about Ridgeline can be found at www.ridgelineminerals.com.

On behalf of the Board
"Chad Peters"
President & CEO

Further Information:
Chad Peters, P.Geo.
President, CEO & Director
Ridgeline Minerals Corp.
+1 775 304 9773
cpeters@ridgelineminerals.com

Neither the TSX Venture Exchange nor its Regulation Service Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this press release

Cautionary Note regarding Forward-Looking Statements
Statements contained in this press release that are not historical facts are "forward-looking information" or "forward-looking statements" (collectively, "Forward-Looking Information") within the meaning of applicable Canadian securities legislation and the United States Private Securities Litigation Reform Act of 1995. Forward-Looking Information includes, but is not limited to, the anticipated benefits of the Earn-In Agreement and the transaction contemplated thereby. The words "potential", "anticipate", "meaningful", "discovery", "forecast", "believe", "estimate", "expect", "may", "will", "project", "plan", "historical", "historic" and similar expressions are intended to be among the statements that identify Forward-Looking Information. Forward-Looking Information involves known and unknown risks, uncertainties and other factors which may cause the actual results to be materially different from any future results expressed or implied by the Forward-Looking Information. In preparing the Forward-Looking Information in this news release, Ridgeline has applied several material assumptions, including, but not limited to, assumptions that TSX Venture Exchange approval will be granted in a timely manner subject only to standard conditions; the current objectives concerning the Project can be achieved and that its other corporate activities will proceed as expected; that general business and economic conditions will not change in a materially adverse manner; and that all requisite information will be available in a timely manner. Forward-Looking Information involves known and unknown risks, uncertainties and other factors which may cause the actual results, performance, or achievements of Ridgeline to be materially different from any future results, performance or achievements expressed or implied by the Forward-Looking Information. Such risks and other factors include, among others, risks related to dependence on key personnel; risks related to unforeseen delays; risks related to historical data that has not been verified by the Company; as well as those factors discussed in Ridgeline's public disclosure record. Although Ridgeline has attempted to identify important factors that could affect Ridgeline and may cause actual actions, events, or results to differ materially from those described in Forward-Looking Information, there may be other factors that cause actions, events or results not to be as anticipated, estimated or intended. There can be no assurance that Forward-Looking Information will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on Forward-Looking Information. Except as required by law, Ridgeline does not assume any obligation to release publicly any revisions to Forward-Looking Information contained in this news release to reflect events or circumstances after the date hereof or to reflect the occurrence of unanticipated events.

To view the source version of this press release, please visit https://www.newsfilecorp.com/release/278452

FAQ

What were the main assay highlights from Ridgeline's SE25-053 at Selena (RDGMF) on December 18, 2025?

Highlights include 8.7m @ 175.5 g/t AgEq from 1,069m, 1.1m @ 27.0% Zn (766.4 g/t AgEq) from 943m, and 17.4m @ 6.0% Zn (219.9 g/t AgEq).

How deep was the high-grade SE25-053 discovery reported by Ridgeline (RDGMF)?

The reported sulfide horizons start at depths of roughly 943m to 1,069m downhole.

What does South32's earn-in mean for Ridgeline shareholders (RDGMF)?

Under the earn-in, South32 may earn an initial 60% by funding US$10M and can increase to 80% with an additional US$10M (US$20M total).

Is follow-up drilling underway at Selena after SE25-053 (RDGMF)?

Yes. Follow-up hole SE25-054 is in progress (≈700m step-out) and assays will be released as received in 2026.

Were the assay samples independently tested for Ridgeline's Selena results (RDGMF)?

Yes. Samples were submitted to American Assay Laboratories with independent checks at Paragon Geochemical Labs and QA/QC protocols including CRM standards and duplicates.

Do the press release assays state true thickness for the Selena intercepts (RDGMF)?

The release notes true thickness is unknown for at least the 1.1m 27.0% Zn intercept.