NexGen Energy's Rook I Project in the Athabasca Basin, Saskatchewan contains the Arrow Deposit — 229.6 million pounds of uncontracted uranium reserves (NI 43-101 Feasibility Study, February 22, 2021) plus contracted reserves. On August 6, 2025, NexGen announced a new 5 million pound uranium offtake contract (1 million lb/year over 5 years from first year of commercial production) with a major US-based utility — doubling its contracted volumes from December 2024 agreements. The Patterson Corridor East (PCE) discovery, 3.5 km from Arrow, has returned extraordinary high-grade results including RK-25-256 at 0.5m of 74.8% UO₂ (May 2025 — one of the highest-grade uranium assays ever recorded). Additional 2025 results include RK-25-240: 0.5m at 33.3% UO₂ at 670m depth and RK-25-239: 0.5m at 30.2% UO₂ at 400m depth. CEO Leigh Curyer: "As the Rook I Project enters into major construction this summer, we continue to advance PCE." Construction is subject to CNSC approval.