Mr. David Cates reports

DENISON & YA'THI NENE LANDS AND RESOURCES ANNOUNCE SIGNING OF THE NUHENENE BENEFIT AGREEMENT WITH THREE FIRST NATIONS AND FOUR MUNICIPALITIES

Denison Mines Corp. and the Ya'thi Nene Land and Resource Office (YNLR) have signed the Nuhenene benefit agreement, which is a regional mutual benefits agreement between Denison and the Hatchet Lake Denesuline First Nation, the Black Lake Denesuline First Nation, the Fond du Lac Denesuline First Nation, the Northern Hamlet of Stony Rapids, the Northern Settlement of Uranium City, the Northern Settlement of Wollaston Lake, the Northern Settlement of Camsell Portage (collectively, the Athabasca communities) and the YNLR. The agreement provides the Athabasca communities' consent to and support for the development and operation of Denison's majority owned and operated Wheeler River project and Waterbury Lake project and also includes Denison's minority interest in the Midwest project (25.77 per cent Denison owned) and the operating McClean Lake project (22.5 per cent Denison owned), all of which are located in Northern Saskatchewan.

David Cates, president and chief executive officer of Denison, commented: "The execution of the Nuhenene benefit agreement marks another significant milestone for Denison and the Wheeler River project, which is in the final stages of the federal approval process for the environmental assessment and construction licence for the planned Phoenix in situ recovery uranium mine. Negotiations of the agreement began following the signing of an exploration agreement between Denison and the Athabasca communities in 2022. Since that time, our team has focused its extensive engagement efforts towards cultivating a strong and enduring relationship built on trust and mutual respect. We are honoured to sign this agreement and extend our sincere appreciation to the leadership of the Athabasca communities, the YNLR board members involved in the negotiation process, and the numerous community members and support staff that have contributed to our engagement activities over the last several years."

"This agreement shows what we can achieve when we put our people and our land at the centre of every decision," said Chief Bart Tsannie of Hatchet Lake Denesuline First Nation. "We expect responsible development, and we expect real benefits for our communities. This agreement delivers on that."

Chief Coreen Sayazie of Black Lake Denesuline First Nation commented: "YNLR led these negotiations with dedication and we are proud of all who contributed to this work. Denison came to the table with honesty and integrity, and that helped us reach a fair and meaningful agreement. This agreement is the result of many voices working together for the Athabasca region, and it is a major achievement for all our communities."

"As Chief of Fond du Lac Denesuline First Nation, I believe this partnership will help build long-term prosperity for the Athabasca region," said Chief Ronnie Augier. "We believe in sustainable development, but also in strong protection of the land we depend on. Balancing these two priorities is central to Fond du Lac's and YNLR's work, and this agreement supports that balance for our children and future generations."

The chairperson of Wollaston Lake Post, Terri Daniels, commented: "This agreement creates real opportunities for our people -- good jobs, strong training programs and space for our local businesses to grow. These benefits will help our members participate fully in the northern economy."

Mayor Daniel Powder of Stony Rapids stated: "This agreement reflects years of hard work to protect our rights, our land and our way of life. It is a positive step that honours our values while creating opportunities for our people to benefit from activity in our territory."

"Independent environmental monitoring has always been a priority for our communities," said Uranium City chairperson Duane Larocque. "This agreement strengthens our role in overseeing the land, the water and the wildlife. It gives us a clear role in making sure the activities are carried out with respect and transparency."

Chairperson Claire Larocque of Camsell Portage said: "Our seven Athabasca communities have worked side by side for many years, and this agreement reflects the strength of that unity. When we stand together, we open the door to real opportunities and positive outcomes for our region."

"Our ongoing work with Denison has shown their readiness to listen, collaborate and support the priorities of Athabasca residents," said Mary Denechezhe, board chair of YNLR. "This agreement builds on that foundation and creates meaningful opportunities for our communities while supporting responsible development."

Nuhenene benefit agreement

The agreement acknowledges that the projects are located within the Nuhenene traditional land of the Athabasca Denesuline and provides Denison with the Athabasca communities' consent and support to advance the projects. Amongst other key commitments, the agreement provides the Athabasca communities and its members an important role in environmental oversight, with specific recognition and support for the protection of the woodland caribou and for surface water monitoring. The agreement also commits to the sharing of benefits from the successful operation of the projects -- including community investment, business opportunities, employment and training opportunities, and financial compensation.

Over all, the agreement describes a jointly held vision for the future that reflects a mutual commitment to maintain an open, respectful and co-operative relationship between Denison and the Athabasca communities. Importantly, the agreement defines the characteristics of the positive legacy that will be associated with the sustainable development of the projects.

About Denison Mines Corp.

Denison is a leading uranium mining, development and exploration company with interests focused in the Athabasca basin region of Northern Saskatchewan, Canada. Denison has an effective 95-per-cent interest in its flagship Wheeler River uranium project, which is the largest undeveloped uranium project in the infrastructure-rich eastern portion of the Athabasca basin region of Northern Saskatchewan.

In mid-2023, the Phoenix feasibility study was completed for the Phoenix deposit as an ISR (in situ recovery) mining operation and an update to the previously prepared 2018 prefeasibility study (PFS) was completed for Wheeler River's Gryphon deposit as a conventional underground mining operation. Based on the respective studies, both deposits have the potential to be competitive with the lowest-cost uranium mining operations in the world. Permitting efforts for the planned Phoenix ISR operation commenced in 2019 and are nearing completion with approval in July, 2025, of the project's EA by the Province of Saskatchewan and commencement in October, 2025, of the Canadian Nuclear Safety Commission hearings for federal approval of the EA and project construction licence. The hearing is scheduled to continue and be concluded during the week of Dec. 8, 2025.

Denison's interests in Saskatchewan also include a 22.5-per-cent ownership interest in the McClean Lake joint venture (MLJV), which includes unmined uranium deposits (with mining at McClean North deposit through the MLJV's Sabre mining method having commenced in July, 2025, using the MLJV's Sabre mining method) and the McClean Lake uranium mill (currently utilizing a portion of its licensed capacity to process the ore from the Cigar Lake mine under a toll milling agreement), plus a 25.17-per-cent interest in the Midwest joint venture Midwest Main and Midwest A deposits and a 70.55-per-cent interest in the Tthe Heldeth Tue (THT) and Huskie deposits on the Waterbury Lake property. The Midwest Main, Midwest A, THT and Huskie deposits are located within 20 kilometres of the McClean Lake mill. Taken together, Denison has direct ownership interests in properties covering approximately 384,000 hectares in the Athabasca basin region.

Additionally, through its 50-per-cent ownership of JCU (Canada) Exploration Company Ltd., Denison holds interests in various uranium project joint ventures in Canada, including the Millennium project (JCU: 30.099 per cent), the Kiggavik project (JCU: 33.8118 per cent) and Christie Lake (JCU: 34.4508 per cent).

In 2024, Denison celebrated its 70th year in uranium mining, exploration and development, which began in 1954 with Denison's first acquisition of mining claims in the Elliot Lake region of Northern Ontario.

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