Denison Mines Corp. Announces Signing of Impact Benefit Agreement and Exploration Agreement with Metis Nation-S Nr-1, and Mn-S Nr-3

Denison Mines Corp. announced the signing of an Impact Benefit Agreement ("IBA") between Denison and the Metis Nation-Sask Saskatchewan ("MN-S"), 13 MN-S Locals, MN-S Northern Region 1 ("MN-S NR-1"), and MN-S Northern Region 3 ("MN-S NR-3") (collectively, the "Metis Parties"). The IBA confirms the Metis Parties' consent to and support for the development and operation of Denison's flagship Wheeler River Project (the "Project") in northern Saskatchewan.

In addition, the parties have also entered into an Exploration Agreement (the "Exploration Agreement") covering Denison's exploration and evaluation activities within MN-S NR-1 and MN-S NR-3 of the Metis Homeland. The IBA acknowledges that the Project is located within the Metis Homeland and emphasizes a shared commitment to ensuring that the successful execution of the Project meaningfully supports the Metis Parties' broader social and economic priorities. This agreement sets out a framework for a long-term relationship grounded in trust, transparency, and mutual respect.

Forming both the IBA and the Exploration Agreement reflects the progress they have made together, and also shared commitment to ensuring that the interests, knowledge, and voices of Metis citizens in Saskatchewan are meaningfully incorporated into the construction and future operation of the Project and Denison's exploration and evaluation activity in MN-S NR-1 & MN-S NR-3. The IBA was entered into by Denison (on its own behalf and as operator on behalf of the Wheeler River Joint Venture), the MN-S, MN-S NR-1, MN-S NR-3 and each of the following MN-S Locals within MN-S NR- 1 or MN-S NR-3, which are comprised of citizens who live and practice traditional activities in the vicinity of the Wheeler River Project: Uranium City Local 50, Stony Rapids Local 80, La Ronge Local 19, Weyakwin Local 16, Timber Bay Local 20, Patuanak Local 82, Ile-a-la-Crosse Local 21, Canoe River Local 174, Jans Bay Local 37, Cole Bay Local 41, Dore/Sled Lake Local 67, and Green Lake Local 5 (collectively, the " Metis Locals"). Impact Benefit Agreement. The IBA recognizes that the Project is located within The Metis Homeland and emphasizes a share commitment to ensuring that the successful executed of the Project meaning fully supports the Metis parties' broader social and economic priorities".

This agreement sets out a framework For a long-term economic priorities.