Métis Nation–Saskatchewan, Northern Region II Affirms Strong Relationship with NexGen and Support for Rook I Project

Press Release

Saskatoon, SK – March 4, 2025 – Métis Nation–Saskatchewan (“MN–S”) and MN–S Northern Region II (“NRII”) are affirming their strong relationship with NexGen Energy Ltd. (“NexGen” or the “Company”) (TSX: NXE) (NYSE: NXE) (ASX: NXG), including their support for advancing the Rook I Project in Saskatchewan (“Rook I Project”).

As previously announced on June 15, 2023, MN–S, NRII and NexGen concluded an industry leading impact benefit agreement in respect of the Rook I Project. The Agreement defines the environmental, cultural, economic, employment and other benefits to be provided to MN-S and NRII by NexGen in respect of the Rook I Project, and confirms the consent and support of MN–S and NRII for the Rook I Project.

The strong relationship and partnership between NRII, MN–S and NexGen reflects how industry and Indigenous Nations can collaboratively work together to implement Call to Action #92 of the Truth and Reconciliation Commission. This partnership is unaffected by a recent decision of the Supreme Court of Canada released on February 28, 2025, addressing certain broader matters between the Province of Saskatchewan, NRII and MN-S in relation to the Crown’s duty to consult. The decision indirectly relates to certain now-expired exploration permits issued by the Province of Saskatchewan for field activities undertaken in 2021, and has no direct impact on NexGen or its activities in respect of the advancement of the Rook I Project. NexGen took no position in respect of these proceedings, and did not participate in the hearings at the Supreme Court of Canada.

NRII and the MN–S have stated their strong support to the Government of Canada and the Canadian Nuclear Safety Commission (CNSC) for NexGen and the Rook I Project. NRII, MN-S and NexGen remain fully committed to advancing the Rook I Project in a spirit of partnership and collaboration, as contemplated in their industry leading impact benefit agreement.

Leonard Montgrand, MN-S Regional Director for NRII, commented: “The Rook

1 Project is bringing once-in-a-lifetime opportunities and change to our Citizens in NRII. NexGen has shown leadership in the industry, by working with us, and

recognizing our voice and our people, just as the Supreme Court of Canada has in its February 28th decision. We have been working closely with CNSC and have voiced our support for an immediate Commission Hearing Date and approval of this generational Project. We applaud NexGen for its leadership and its respectful and collaborative approach, and we look forward to the development of the Rook 1 Project.”

About Métis Nation–Saskatchewan

Métis Nation–Saskatchewan (MN–S) is built on a foundation of Métis identity, culture, values and language. Empowered by the Métis citizens of Saskatchewan, MN–S works to advance Métis rights and strengthen capacity. MN–S represents the political, socioeconomic, cultural and educational interests of Métis in the province through an elected representative system at local, regional and provincial levels. Social Media Links: @MNSask, @metisnationsask

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