Cosa Announces Expansions to Orion Project and Joint Ventures with Denison Mines

Vancouver, British Columbia, March 3, 2026 – Cosa Resources Corp. (TSX-V: COSA) (OTCQB: COSAF) (FSE: SSKU) (“Cosa” or the “Company”) is pleased to announce expansions to the Murphy Lake North (“MLN”), Darby (“Darby”), and Orion (“Orion”) projects (Figure 1). Darby and MLN are joint ventures (the “Joint Venture”) between Cosa and Denison Mines Corp. (“Denison”) (TSX: DML) (NYSE American: DNN) and are located 10 kilometres west of Cameco’s Cigar Lake Mine and three kilometres east of IsoEnergy’s Hurricane Deposit, respectively. Cosa is the operator of both and holds a 70% interest with Denison holding a 30% interest in each. Orion is 100% owned by Cosa and is located 5 kilometres northwest of Darby.