Mr. Keith Bodnarchuk reports

COSA COMMENCES AIRBORNE GEOPHYSICAL SURVEYING AT THE ASTRO URANIUM PROJECT, ATHABASCA BASIN, SASKATCHEWAN

Cosa Resources Corp. has commenced airborne geophysical surveying at the Astro uranium project. This work is fully financed by Cosa's partner company, Global Uranium Corp., per the option agreement announced by the company on April 9, 2025, which gives Global the right to earn up to an 80-per-cent interest in the Astro project over five exploration stages. As operator, Cosa has engaged Geotech Ltd. to complete comprehensive coverage over Astro by utilizing their exclusive industry-leading ZTEM (Z-tipper electromagnetic) system

Highlights:

• ZTEM survey and supporting work are fully financed by Global Uranium;
• Property-wide coverage is planned to identify all basement conductive trends within Astro and is expected to significantly increase the amount of known conductive strike within the project;
• Detailed interpretation to follow to identify preliminary follow-up target areas potentially related to structures and/or hydrothermal alteration;
• Astro is an expansive (greater-than-45,000-hectare) eastern Athabasca project, within 30 kilometres of Cameco's McArthur River uranium Mine and within 10 kilometres of Canalaska Uranium Ltd.'s Pike zone discovery.

Survey details

Property-wide ZTEM surveying planned to total over 1,460 line kilometres is under way. Surveying is expected to significantly advance the understanding of the property and identify target areas for follow-up work by mapping conductive trends in the basement, potential zones of hydrothermal alteration in the sandstone, and regional structures believed to be related to the nearby Fox Lake and McArthur River uranium deposits. Historical ZTEM surveys cover less than 25 per cent of the project. By completing project-scale coverage, Cosa and Global aim to rapidly identify and prioritize the most prospective areas at Astro.

Exclusive to Geotech, the ZTEM system is widely used within the Athabasca basin as it boasts a demonstrated industry-leading ability to provide a wide range of frequency measurements with high accuracy and resolution at depth. Condor Consulting Inc., a recognized expert in the field of geophysical data processing and interpretation with extensive experience with both the ZTEM system and the Athabasca basin, has been retained to perform a detailed interpretation of the results.

Results of the survey and data inversion will guide follow-up work, which is likely to include a combination of cutting-edge ambient noise tomography (ANT) surveying and ground-based electromagnetic (EM) surveys through the remainder of 2025 and into early 2026. The most prospective areas identified from these surveys will be prioritized for drill testing as part of a phased exploration program.

About Astro

The Astro project is located roughly 28 kilometres west of Cameco's McArthur River mine, the world's largest high-grade uranium mine, and approximately 10 kilometres west of Canalaska Uranium's Pike zone, which boasts world-class intersections. Airborne geophysics completed in 2023 at Cosa's neighbouring Ursa project confirmed that untested conductive trends continue from Ursa onto the Astro project. Additionally, over 20 kilometres of conductive strike has been identified by historical surveys at Astro, which has been tested by a single drill hole, EK-01. EK-01 failed to explain the strong conductive response it was targeting, suggesting the hole was not ideally located. However, the historical drill log notes favourable features in the sandstone, including a brecciated and silicified interval in the upper portion, decametre-scale intervals of illite-dominated clay mineralogy throughout, and moderately bleached and slightly friable intervals in the lower 150 metres, features that are commonly associated with unconformity-related uranium deposits of the Athabasca basin, including McArthur River, Cigar Lake and Hurricane. Roughly 11 kilometres to the southwest of EK-01 and within 700 metres of the Astro project, strongly anomalous uranium geochemistry and pervasive hydrothermal alteration were intersected in the lower to medial sandstone of historical drill holes CR-06 and CR-15. Drilling completed by Cosa in 2024 failed to explain the source of the geochemical anomaly; however, ground-based EM work completed by Cosa indicates that the targeted conductor likely trends onto the Astro project.

Astro hosts over 40 kilometres of magnetic-low strike that has been untested by drilling, the vast majority of which has not been covered by any modern EM survey. A patchwork of historical airborne and ground EM surveys covering a portion of the contained magnetic-low strike length has defined that conductive trends are present within most surveyed areas. Notably, the project is entirely unexplored for the extension of regional structures related to both the McArthur River and Fox Lake uranium deposits, located roughly 28 kilometres and 17 kilometres east of Astro, respectively. Cosa and Global Uranium will execute a work plan designed to rapidly and efficiently canvas much of the Astro project for early identification of the most compelling and high-upside drill targets. The depth to the unconformity at Astro is estimated to be between 850 metres and 975 metres.

About Cosa Resources Corp.

Cosa Resources is a Canadian uranium exploration company operating in Northern Saskatchewan. The portfolio comprises roughly 237,000 hectares across multiple 100-per-cent-owned and Cosa-operated-joint-venture projects in the Athabasca basin region, all of which are underexplored, and the majority reside within or adjacent to established uranium corridors.

In January, 2025, the company entered a transformative strategic collaboration with Denison Mines that has secured Cosa access into several additional highly prospective eastern Athabasca uranium exploration projects. As Cosa's largest shareholder, Denison gains exposure to Cosa's potential for exploration success and its pipeline of uranium projects.

Cosa's award-winning management team has a long record of success in Saskatchewan. In 2022, members of the Cosa team were awarded the AME Colin Spence Award for their previous involvement in discovering IsoEnergy's Hurricane deposit. Prior to Hurricane, Cosa personnel led teams or had integral roles in the discovery of Denison's Gryphon deposit and 92 Energy's GMZ zone and held key roles in the founding of both NexGen and IsoEnergy.

The company's core focus throughout 2025 is drilling at the Murphy Lake North joint venture. Murphy Lake North is a 70/30 joint venture between Cosa and Denison, respectively, and is located at the northern end of the Larocque Lake trend. The project is within three kilometres of and on trend with the Hurricane deposit. Initial drilling completed by Cosa during winter 2025 intersected broad zones of hydrothermal alteration of the sandstone, associated with prospective basement structures interpreted as the strike extension of those controlling the Hurricane deposit. An expanded follow-up campaign is currently in planning for the summer season.

Technical disclosure

Historical exploration results disclosed in this news release were sourced from the Saskatchewan Mineral Assessment Database (SMAD). These results have not been verified by the qualified person except as noted below and are relied upon for qualitative assessment of the project only. At present, the company does not intend to complete additional verification of historical results. SMAD sources for Astro include 74-0015, 74H13-0009, 74H11-0113, 74G16-0010, 74H13-0015 and 74H13-0016.

Verification of historical drilling results included confirming the approximate collar location of historical drill hole EK-01 from air photos. Verification of geophysical results is limited to verification of selected local grid locations for SMAD files 74-0015 and 74H13-0009 and qualitatively assessing whether drilling results from survey areas or along the interpreted strike can reasonably explain historical geophysical interpretations.

Qualified person

The company's disclosure of technical or scientific information in this press release has been reviewed and approved by Andy Carmichael, PGeo, vice-president, exploration, for Cosa. Mr. Carmichael is a qualified person as defined under the terms of National Instrument 43-101.

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