 Signs Impact Benefit Agreement with Buffalo River Dene Nation, Signs Mutual Benefit Agreement with Birch Narrows Dene Nation, Appoints Community Based Project Liaison Manager, and The Court of Queens Bench for Saskatchewan Dismisses MN-S Application, VANCOUVER, BC, July 14, 2021 PRNewswire - NexGen Energy Ltd. NexGen or the Company TSX: NXE NYSE MKT: NXE is pleased to announce the signing of an Impact Benefit Agreement IBA with the Buffalo River Dene Nation BRDN, and the signing of a Mutual Benefit Agreement MBA with the Birch Narrows Dene Nation BNDN, covering all phases of the Rook I Project Rook I or the Project, which hosts the 100 owned Arrow uranium deposit. 