Mr. Jason Barnard of Foremost Clean Energy reports

FOREMOST CLEAN ENERGY TO EARN MAJORITY INTEREST ACROSS ATHABASCA URANIUM PORTFOLIO UNDER DENISON OPTION AGREEMENT

Foremost Clean Energy Ltd. will have completed the phase 2 earn-in requirements under its option agreement closed with Denison (see press release dated Oct. 7, 2024) upon issuing to Denison Mines Corp. up to 848,610 common shares in the capital of Foremost valued at $2-million (based on applicable pricing parameters).

Highlights:

• Will earn a 51-per-cent interest in 10 Athabasca uranium projects, with the exception of its Hatchet Lake project, where Foremost will hold a 35.78-per-cent interest;
• Phase 2 of the three-phase option agreement to be completed approximately 15 months ahead of the October, 2027, deadline.

The company has completed more than $8-million in qualifying exploration expenditures and, upon completion of phase 2, will have increased its ownership interest to 51-per-cent interest across its 10 Athabasca uranium projects, with the exception of Hatchet Lake, at 35.78 per cent. The significant earn-in milestone is expected to be satisfied approximately 15 months ahead of the Oct. 4, 2027, contract deadline.

The projects encompasses 45 mineral claims covering approximately 332,378 acres (134,509 hectares) across Saskatchewan's Athabasca basin, one of the world's premier uranium-producing jurisdictions. The portfolio includes advanced, discovery-ready and drill-permitted uranium exploration assets strategically located adjacent to, or in close proximity to, several of the world's largest and highest-grade uranium operations, including the McArthur River mine, Cigar Lake mine, and McClean Lake mill. The projects are located along the prolific Wollaston-Mudjatik transition zone (WMTZ), the structural corridor that hosts all currently operating uranium mines and mills in the eastern Athabasca basin.

Jason Barnard, president and chief executive officer of Foremost, commented: "When we entered into this strategic agreement with Denison in October, 2024, the global nuclear energy landscape was rapidly evolving, and our mission was clear: to systematically advance this exceptional portfolio of Athabasca uranium projects through disciplined, science-driven exploration. By combining Denison's decades of geological knowledge and historical exploration data with our own technical expertise and systematic exploration strategy, we have completed more than $8-million in exploration expenditures, made a new uranium discovery at Hatchet Lake, advanced multiple projects through drilling, geophysics and permitting, and generated a growing pipeline of high-priority exploration targets across the portfolio.

"Achieving the completion of phase 2 approximately 15 months ahead of our contractual obligations represents a major milestone for Foremost. Earning a majority interest in our uranium portfolio reflects our commitment to uranium exploration and positions Foremost to continue advancing high-priority uranium targets at a time when global demand for secure uranium supply and nuclear energy continues to strengthen."

Option agreement earn-in summary

The option agreement provides Foremost with the opportunity to earn up to 70-per-cent interest (51 per cent of Hatchet Lake) in the projects through a three-phase earn-in structure, summarized below in Table 1. Upon completing phase 2, the company's next objective will be advancing the final earn-in phase (phase 3). Once Foremost completes its option exercises in accordance with the option agreement, Foremost will become a party to the existing Hatchet Lake joint venture agreement and will enter into new joint venture agreements with Denison governing the future development of the other uranium projects.

Since entering into the option agreement with Denison, the company has systematically advanced multiple projects from historical targets to discovery-ready drill opportunities by integrating Denison's decades of historical drilling, geophysical data sets and geological interpretation with Foremost's own exploration programs, geophysical surveys and technical interpretation. Some of the exploration activities completed to date include, but are not limited to:

• Discovery of the Tuning Fork uranium zone at Hatchet Lake South, where drilling intersected 6.2 metres grading 0.10 per cent U3O8 (triuranium octoxide), including 0.87 per cent U3O8 over 0.45 metres, followed by successful stepout drilling that expanded the mineralized footprint during the 2026 winter drill program (see news releases dated Oct. 29, 2025, and May 26, 2026);
• Completion of a 19-hole, 3,848-metre diamond drill program at Hatchet Lake South that expanded the Tuning Fork uranium zone and demonstrated encouraging continuity of mineralization along a conductive structural corridor (see news release dated May 26, 2026);
• Completion of a 2,695-metre diamond drill program at Murphy Lake South, where drilling intersected strong hydrothermal alteration, reactivated graphitic shear zones and elevated radioactivity across an approximately 400-metre alteration footprint (see news release dated May 27, 2026);
• Completion of a 771-line-kilometre MobileMT airborne geophysical survey over the CLK project to define additional drill-ready targets (see news release dated April 14, 2025);
• Completion of a detailed 893-station radon survey at Wolverine that identified multiple kilometre-scale radon anomalies coincident with favourable structural trends (see news release dated June 25, 2025);
• Advancement of Turkey Lake through permitting and completion of a ground gravity survey ahead of the planned 2026 diamond drill program (see news releases dated Dec. 30, 2025 (permit), and Feb. 3, 2026 (2026 exploration program)).

Denison's holdings

Denison held 2.6 million shares, representing approximately 15.8 per cent of Foremost's issued and outstanding shares, prior to the issuance of the phase 2 shares. On completion of the issuance to Denison of the phase 2 shares, Denison is expected to hold 3,448,610 shares, representing approximately 19.9 per cent of Foremost's then issued and outstanding shares. Denison also holds 607,600 Foremost warrants, representing approximately 17 per cent of the issued and outstanding warrants of Foremost. This information is being provided under the early warning requirements of applicable securities laws. Denison will be filing an early warning report under the company's profile on SEDAR+ pursuant to National Instrument 62-103 in respect of the change in its common shareholdings in Foremost upon receipt of the phase 2 shares. Equity in Foremost was acquired by Denison for investment purposes. Denison intends to review, on a continuous basis, various factors related to its investment in Foremost and may decide to acquire or dispose of additional securities of Foremost as future circumstances may dictate, including under its pre-emptive rights under the investor rights agreement. For further information, Denison can be contacted at Suite 1100, 40 University Ave., Toronto, Ont., M5J 1T1, attention: Geoff Smith, vice-president, corporate development and commercial, at info@denisonmines.com.

Looking ahead

With the company now focused on advancing phase 3 under the option agreement, Foremost intends to continue actively advancing its Athabasca basin uranium portfolio, with exploration and drilling programs currently under way across multiple projects. Backed by a strong technical foundation, financial flexibility and a disciplined exploration strategy, the company's objective remains clear: to efficiently advance and delineate the next significant uranium discovery in one of the world's premier uranium jurisdictions.

Qualified person

The technical content of this news release has been reviewed and approved by Cameron MacKay, PGeo, vice-president of exploration for Foremost Clean Energy and a qualified person under NI 43-101.

A qualified person has not performed sufficient work or data verification to validate the historical results in accordance with NI 43-101. Although the historical results may not be reliable, the company nevertheless believes that they provide an indication of the property's potential and are relevant for any future exploration program.

About Foremost Clean Energy Ltd.

Foremost Clean Energy is a North American uranium and lithium exploration company strategically positioned to support the accelerating demand for reliable, carbon-free energy. As artificial intelligence, data centres and electrification drive unprecedented growth in global power consumption, the expanding need for reliable nuclear baseload power creates a direct and critical imperative for the sustained exploration required to secure its uranium feedstock.

The company holds an option from Denison to earn up to a 70-per-cent interest in 10 prospective uranium properties (except for the Hatchet Lake project, where Foremost can earn up to 51 per cent), spanning over 330,000 acres in the prolific, uranium-rich Athabasca basin region of Northern Saskatchewan. The company employs a data-driven exploration strategy supported by extensive historic drilling and geophysical data across its portfolio, including programs completed by Denison, providing a validated road map and competitive advantage for targeting high-potential, mineralized trends. To date, Foremost has completed geophysical surveys and multiple drill campaigns that have generated encouraging results and defined high-priority, discovery-ready targets for follow-up drilling.

Foremost also has a portfolio of lithium projects at varying stages of development spanning greater than 43,000 acres in Manitoba, providing exposure to other critical materials essential in electrification and energy storage.

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