Cosa Announces Summer Drill Plans for the Darby Joint Venture with Denison Mines

Operational Update and Drilling Schedule

• Cosa Resources Corp. announced summer drilling plans for its Darby joint venture project, located 10 km west of Cameco's Cigar Lake Mine in the eastern Athabasca Basin.
• Planned drilling will target the Gamma and Bravo trends to follow up on anomalous uranium geochemistry, structural features, and alteration identified during winter 2026 and historical drilling.
• Darby drilling is scheduled to commence in late August 2026, immediately following the completion of a significant, minimum two-month drill program at the Company's Murphy Lake North (MLN) joint venture.
• The MLN program, comprising approximately 6,000 metres across 15 drill holes, is expected to finish in late August. It follows up on a recent winter 2026 intersection of 5.0 metres averaging 0.55% U3O8.
• Denison Mines Corp. holds a 30% interest in both the Darby and MLN joint ventures, with Cosa serving as operator.

Routine Execution of Planned Exploration

• The news release is a routine operational update confirming the execution of previously announced exploration timelines.
• The MLN winter intercept of 5.0m @ 0.55% U3O8 (including 0.5m @ 1.70% U3O8) was already disclosed on May 26, 2026, and rated as Material - Positive at that time.
• The Darby summer plans are incremental and expected, focusing on follow-up targets identified from historical data and recent winter results.
• No new material catalysts, unexpected financial terms, or strategic shifts are introduced. The announcement simply confirms the company's exploration schedule and capital deployment for the remainder of 2026.
• The recent C$5.02M private placement (announced June 3, 2026) provides the necessary liquidity to fund these upcoming programs, mitigating near-term capital concerns.

Exploration Focus and Project Portfolio

• Cosa Resources Corp. is a uranium exploration company focused on the Athabasca Basin in Saskatchewan, Canada.
• Flagship projects are the Murphy Lake North (MLN) and Darby projects, both structured as 70% Cosa / 30% Denison Mines joint ventures.
• MLN is located 3 km east of IsoEnergy's world-class Hurricane deposit, featuring strong sandstone alteration and graphitic faulting.
• Darby is located 10 km west of Cameco's Cigar Lake Mine, with historical drilling indicating multiple highly prospective conductive trends.
• The company also holds 100% interests in Ursa, Orion, and Orbit, and has optioned Aurora to Traction Uranium and Astro to Global Uranium.
• The company is in the exploration stage with no defined mineral resources or reserves.