Cosa Reports Anomalous Uranium in Sandstone at Darby Joint Venture with Denison Mines

Vancouver, British Columbia, May 06, 2026 – Cosa Resources Corp. (TSX-V: COSA) (OTCQB: COSAF) (FSE: SSKU) (“Cosa” or the “Company”) is pleased to report drilling results for the Company’s Darby (“Darby”) project. Darby is a joint venture (the “Joint Venture”) between Cosa and Denison Mines Corp. (“Denison”) (TSX: DML) (NYSE American: DNN) and is located 10 kilometres west of Cameco’s Cigar Lake Mine in the eastern Athabasca Basin, Saskatchewan (Figure 1). Cosa is the operator of Darby and holds a 70% interest with Denison holding a 30% interes