Denison Mines: Peter Ballantyne Cree Nation Withdraws Court Challenge, Confirms Support for Wheeler River

• Peter Ballantyne Cree Nation ("PBCN") has withdrawn its judicial review application filed with the Court of King's Bench for Saskatchewan concerning the Environmental Assessment approval for the Phoenix in-situ recovery ("ISR") uranium mine.
• Following further engagement with Denison, PBCN has formally provided its consent to and support for the development and operation of the Wheeler River project.
• Phoenix's Environmental Assessment was approved by the Province of Saskatchewan in July 2025 and by the Canadian Nuclear Safety Commission in February 2026, alongside the grant of a construction licence.
• Site preparation and early works construction for Phoenix began in March 2026.
• Denison continues to target first production from Phoenix in 2028.

Denison Mines Corp. (TSX: DML) (NYSE American: DNN) is a Canada-based uranium exploration and development company concentrated in the Athabasca Basin region of northern Saskatchewan. Its principal asset is the Wheeler River project, in which it holds an effective 95% interest, home to the high-grade Phoenix and Gryphon deposits. Beyond Wheeler River, Denison holds ownership stakes in several other Athabasca Basin assets, including the McClean Lake Joint Venture and its uranium mill, the Midwest Joint Venture, and the Waterbury Lake property. Through a 50% holding in JCU (Canada) Exploration Company, the company also has interests in additional uranium projects across Canada. Denison has been active in uranium mining, exploration and development since 1954.

PBCN Withdrawal of Judicial Review Against Phoenix ISR Environmental Assessment Approval

PBCN had applied for a judicial review in the Court of King's Bench for Saskatchewan, challenging the provincial Environmental Assessment approval granted for the Phoenix ISR mine. A judicial review is a court process that examines whether a government approval, in this case the environmental approval issued by the Province of Saskatchewan, was granted properly.

PBCN has now withdrawn this application. The Environmental Assessment approval for Phoenix remains in place. The withdrawal followed continued engagement between Denison and PBCN after the application was filed.

The withdrawal is confirmed directly by Denison in the release and applies specifically to the judicial review proceeding concerning the Phoenix Environmental Assessment approval.

PBCN Formal Consent and Support for Wheeler River Project Development and Operation

In addition to withdrawing its judicial review, PBCN has formally provided its consent to and support for the development and operation of the Wheeler River project as a whole, extending beyond the Phoenix approval that was the subject of the court application.

This consent followed further engagement between Denison and PBCN in the period after the judicial review was filed.

The release confirms this as a formal position from PBCN regarding both the development and the ongoing operation of Wheeler River.

Strengthened Indigenous Relations Supporting Phoenix Construction Progress Toward 2028 Production

Phoenix has received its principal regulatory approvals. The Province of Saskatchewan approved the project's Environmental Assessment in July 2025, and the Canadian Nuclear Safety Commission approved the Environmental Assessment and granted the construction licence in February 2026. Site preparation and early works construction began in March 2026.

Denison continues to target first production from Phoenix in 2028.

PBCN's withdrawal of its judicial review and its formal support for Wheeler River were announced during this period of active construction at Phoenix.

Milestones and Next Steps

Site preparation and early works construction at Phoenix, which began in March 2026, are ongoing. Denison continues to target first production from the ISR operation in 2028. PBCN's withdrawal of its judicial review and its formal consent to and support for Wheeler River's development and operation were both confirmed in this release.

‍