New Uranium Mineralized Roll Fronts Discovered Adjacent to Existing Wellfields at the Alta Mesa In-Situ Recovery Uranium Project

Rhea-AI Summary

enCore Energy (NASDAQ: EU) announced discovery of multiple new uranium mineralized roll fronts at the Alta Mesa ISR Uranium Project on Oct 15, 2025 following a re-analysis of historic drill holes begun April 2025.

Key highlights: roll fronts in at least three areas, one advanced to permitting as Wellfield 3 Extension, two new roll fronts overlying Wellfield 4 each >2,500 ft, and shallow mineralization at 320–345 ft (~200 ft above prior targets) that may reduce drilling and extraction costs.

Positive

• At least 3 new roll fronts identified from re-analysis
• One discovery progressed to permitting as Wellfield 3 Extension
• Two roll fronts overlying Wellfield 4, each >2,500 ft
• Shallow mineralization at 320–345 ft, ~200 ft shallower than prior targets

Negative

• None.

Insights

Uranium Exploration Strategist

New near‑surface roll fronts at Alta Mesa increase accessible ISR targets and cut drill and extraction costs.

enCore reports newly identified uranium roll fronts adjacent to existing wellfields, including a Wellfield 3 Extension now in permitting and at least two new roll fronts in Wellfield 4 each extending more than 2500 feet. The company states the new mineralization lies at depths of 320 to 345 feet, roughly 200 feet above prior exploited fronts, and that ISR‑saturated horizons exist within the B Sand of the Goliad Formation; reported intercepts show Grade Thickness values at or above the 0.3% GT threshold noted as suitable for ISR inclusion.

The business effect flows from proximity to existing infrastructure and shallower depth, which can reduce drilling time, casing and cement needs, and delineation cost per pound recovered. Key dependencies include successful permitting for Wellfield 3 Extension, confirmation of continuity and recoverability of the new roll fronts through ongoing delineation drilling, and inclusion of intercepts above the stated GT cutoff in operational wellfields; technical approval is noted by a Qualified Person. Watch follow‑up drilling results through end of the year and into 2026, permit approvals for Wellfield 3 Extension, and conversion of these intercepts into permitted, ISR‑recoverable wellfield plans within the existing permit footprints for Wellfield 4.

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www.encoreuranium.com

DALLAS, Oct. 15, 2025 /PRNewswire/ - enCore Energy Corp. (NASDAQ: EU) (TSXV: EU) (the "Company" or "enCore"), America's Clean Energy Company™, announced today important new uranium discoveries have been made in areas in or near existing wellfields. These discoveries have been made as a result of a major ongoing re-analysis of thousands of historic drill holes from across the Alta Mesa In-Situ Recovery ("ISR") Uranium Project that began in April 2025. This more granular and detailed evaluation has identified uranium mineralized roll fronts in at least three areas to date. Follow up drilling by enCore has delineated these new roll fronts with drilling continuing to determine the extents of each.

To view the project map, please visit: https://shorturl.at/wf2Wp

This additional roll front uranium mineralization has been discovered in close proximity to known and already exploited roll fronts. One of these new roll fronts has progressed such that it has now advanced to permitting as Wellfield 3 Extension. Mineralized roll fronts have also been found overlying the past productive mineralization in Wellfield 4 with at least two new roll fronts discovered to date, each extending more than 2500 feet in length with both included in the existing permit authorization. This newly discovered mineralization lies at a depth of 320 to 345 feet, almost 200 feet above the previously exploited roll front. This shallow mineralization makes for shorter drill times with less footage required, less cement and shorter casing intervals resulting in significant cost savings in delineation and extraction versus deeper mineralization. A third area extending south from the previously exploited mineralization in Wellfield 1 continues to expand with additional ongoing drilling.

This granular re-analysis of previous drill data is expected to continue through the end of the year with follow-up delineation drilling continuing into 2026. This drilling is in addition to the major drill program, expected to commence in the next few weeks, on the recently acquired Alta Mesa East Property (EU NR dated August 18, 2025) which hosts the extensions of roll front uranium mineralization from several of the Wellfields to the west on the established Alta Mesa Project.

Current and historical drilling highlights are shown below:

Current (enCore) *cutoff values reflect 0.02 grade
Drill Hole	Goliad Sandstone Horizon	Depth (ft)	Thickness (ft)	Grade % U3O8	Grade Thickness (GT)
148.5-94.6	B	335.5	5.5	0.277	1.522
147.4-95.3	B	329	8.5	0.154	1.13
147.7-93.9	B	340.5	4.5	0.18	0.811
137.4-101.4	B	316	3	0.106	0.318
Historic (Meste ñ a) *cutoff values reflect 0.01 grade
Drill Hole	Goliad Sandstone Horizon	Depth (ft)	Thickness (ft)	Grade % U3O8	Grade Thickness (GT)
142.8-95.5	B	321	4.5	0.1	0.45
140.7-97.7	B	317	3	0.145	0.435
142.9-96.3	B	326	3.5	0.107	0.375
148.5-94.5	B	337.5	2.5	0.129	0.323
131-108.5	B	332	2.5	0.123	0.306
141-98	B	340.5	4	0.06	0.27

All intercepts listed above are located within the B Sand which hosts mineralization within the Goliad Formation. The Company has identified 4 saturated (required for ISR), mineralized sandstone horizons within the B Sand of the Goliad Formation lying approximately 320 to 345 feet below the surface. The water level is located approximately 120 feet below the surface. Grade Thickness is Grade % U3O8 multiplied by the thickness of the mineralization. ISR recoverable uranium with a Grade Thickness of >0.3 is considered suitable for inclusion in a wellfield.

John M. Seeley, Ph.D., P.G., C.P.G., enCore's Vice President of Exploration and Production, and a Qualified Person under Canadian National Instrument 43-101 and U.S. Securities and Exchange Commission S-K 1300, has reviewed and approved the technical disclosure in this news release on behalf of the Company.

The Company has also awarded equity-based grants under the 2024 Long-Term Incentive Plan (the "Plan") to certain of its directors and officers. These grants consist of 60,000 restricted stock units ("RSUs") that cliff vest in one (1) year, 948,031 RSUs to vest ratably over two (2) years, 767,789 RSUs that vest ratably over three (3) years, all of which are subject to the terms and conditions of the Plan.

About the Alta Mesa ISR Uranium CPP and Wellfield ("Alta Mesa Uranium Project")

The Alta Mesa Uranium Project hosts a fully licensed and operational ISR Central Processing Plant and operational wellfield located on 200,000+ acres of private land and mineral rights in and regulated by the state of Texas. Total operating capacity at the Alta Mesa CPP is 1.5 million pounds uranium per year with additional drying capacity of 0.5 million pounds. The Alta Mesa Uranium Project operates under a 70/30 joint venture with Boss Energy Limited which is managed by the Company.

The Alta Mesa Uranium Project utilizes well known ISR technology to extract uranium in a non-invasive process using natural groundwater and oxygen. Currently, oxygenated water is being circulated in the wellfield through injection or extraction wells plumbed directly into the primary pipelines feeding the Alta Mesa CPP. Expansion of the wellfield will continue, with extraction to steadily increase from the wellfield as expansion continues through 2025 and beyond. The Alta Mesa CPP historically produced nearly 5 million pounds of uranium between 2005 and 2013 when production was curtailed as a result of low prices.

About enCore Energy Corp.

enCore Energy Corp., America's Clean Energy Company™, is committed to providing clean, reliable, and affordable fuel for nuclear energy as the only United States uranium company with multiple Central Processing Plants in operation. The enCore team is led by industry experts with extensive knowledge and experience in all aspects of ISR uranium operations and the nuclear fuel cycle. enCore solely utilizes ISR for uranium extraction, a well-known and proven technology co-developed by the leaders at enCore Energy.

Following upon enCore's demonstrated success in South Texas, future projects in enCore's planned project pipeline include the Dewey Burdock project in South Dakota and the Gas Hills project in Wyoming. The Company holds other assets including non-core assets and proprietary databases. enCore is committed to working with local communities and indigenous governments to create positive impact from corporate developments.

www.encoreuranium.com  

Cautionary Note Regarding Forward Looking Statements:

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

This press release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995 and Canadian securities laws that are based on management's current expectations, assumptions and beliefs. Forward-looking statements can often be identified by such words as "will", "expects", "plans", "believes", "intends", "estimates", "projects", "continue", "potential", and similar expressions or variations (including negative variations) of such words and phrases, or statements that certain actions, events or results "may", "could", or "will" be taken.

Forward-looking statements and information that are not statements of historical fact include, but are not limited to, and any statements regarding future expectations, beliefs, goals or prospects, including the Company's strategy to exploit new roll fronts for uranium extraction, to provide nuclear fuel and deliver sustainable value to its shareholders. All such forward-looking statements are not guarantees of future results and forward-looking statements are subject to important risk factors and uncertainties, many of which are beyond the Company's ability to control or predict, that could cause actual results to differ materially from those expressed in any forward-looking statement. A number of important factors could cause actual results or events to differ materially from those indicated or implied by such forward-looking statements, including, without limitation, exploration and development risks, changes in commodity prices, access to skilled personnel, the results of exploration and development activities; extraction risks; uninsured risks; regulatory risks; defects in title; the availability of materials and equipment, timeliness of government approvals and unanticipated environmental impacts on operations; litigation risks; risks posed by the economic and political environments in which the Company operates and intends to operate; increased competition; assumptions regarding market trends and the expected demand and desires for the Company's products and proposed products; reliance on industry equipment manufacturers, suppliers and others; the failure to adequately protect intellectual property; the failure to adequately manage future growth; adverse market conditions, the failure to satisfy ongoing regulatory requirements and factors relating to forward looking statements listed above which include risks as disclosed in the Company's filings on SEDAR+ and with the SEC, including its Annual Report on Form 10-K, Quarterly Reports on Form 10-Q, management discussion and analysis and annual information form. Should one or more of these risks materialize, or should assumptions underlying the forward-looking statements prove incorrect, actual results may vary materially from those described herein as intended, planned, anticipated, believed, estimated or expected. The Company assumes no obligation to update the information in this communication, except as required by law. Additional information identifying risks and uncertainties is contained in filings by the Company with the respective securities commissions which are available online at www.sec.gov and www.sedarplus.ca. 

Forward-looking statements are provided for the purpose of providing information about the current expectations, beliefs and plans of management. Such statements may not be appropriate for other purposes and readers should not place undue reliance on these forward-looking statements, that speak only as of the date hereof, as there can be no assurance that the plans, intentions or expectations upon which they are based will occur. Such information, although considered reasonable by management at the time of preparation, may prove to be incorrect and actual results may differ materially from those anticipated. Forward-looking statements contained in this news release are expressly qualified by this cautionary statement.

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SOURCE enCore Energy Corp.

FAQ

What uranium discoveries did enCore (EU) announce at Alta Mesa on Oct 15, 2025?

enCore announced at least three new mineralized roll fronts near existing wellfields, with one advanced to permitting as Wellfield 3 Extension.

How deep is the newly discovered uranium mineralization at Alta Mesa (EU)?

The new mineralized horizons lie at approximately 320–345 feet below surface, about 200 feet shallower than prior exploited mineralization.

Are any of the new Alta Mesa roll fronts included in existing permits for enCore (EU)?

Yes; two newly discovered roll fronts overlying Wellfield 4 are each >2,500 ft and are included in the company’s existing permit authorization.

What operational benefits did enCore (EU) cite for the shallower Alta Mesa mineralization?

Shallower mineralization reduces drill footage, casing and cement needs, and shortens drill times, which may lower delineation and extraction costs.

What is enCore’s planned timeline for follow-up drilling at Alta Mesa (EU)?

The company said re-analysis will continue through the end of 2025 with follow-up delineation drilling continuing into 2026.

Did enCore (EU) report specific drill intercepts or grades for the new Alta Mesa discoveries?

Yes; the release listed intercepts in the B Sand with examples such as 5.5 ft at 0.277% U3O8 (GT 1.522) and other historic and current intercepts.