Denison Mines Strategic Collaboration

In January 2025, Cosa entered a transformative strategic collaboration with Denison Mines that has secured Cosa access into several additional highly prospective eastern Athabasca uranium exploration projects. These Projects offer Cosa over 20,000 ha of additional exposure into what the Company considers to be mature, discovery-ready projects that are well situated close to existing eastern Athabasca infrastructure and boast several walk-up drill targets based on encouraging results from historical drilling. Most notable is the Murphy Lake North project with is on trend and within four kilometres of IsoEnergy’s Hurricane Deposit which was discovered in 2018 by Cosa’s management and currently holds the title as the world’s highest grade indicated resource in uranium. As Cosa’s largest shareholder, Denison Mines gains exposure to Cosa’s potential for exploration success and its pipeline of uranium deposits.

Murphy Lake North covers a portion of the Larocque Lake trend and is located 3.2 kilometres east of the Hurricane deposit (Figure 2). The Hurricane deposit is the world’s highest-grade Indicated mineral resource for uranium and was discovered and delineated for IsoEnergy Ltd. by current members of Cosa’s management, board of directors, and advisors from 2018 through 2022. The Larocque Lake trend also hosts the Larocque Lake zone, the Yelka Prospect, and the Alligator Lake zone. Murphy Lake North contains approximately six kilometres of conductive strike length oriented sub-parallel to conductive features associated with the Hurricane Deposit. Limited historical drilling completed on Murphy Lake North intersected weak mineralization in the basement and zones of alteration and structure in the sandstone and basement. Historical drilling, completed prior to the discovery of Hurricane, focused on the western extremity of the property and left most of the conductive strike length untested. Abundant drill targets exist at Murphy Lake North and diamond drilling is planned for the first half of 2025.
 

The depth to the unconformity at Murphy Lake North is approximately 250 metres.

The Darby Project is located ten kilometres west of the Cigar Lake Mine and 17 kilometres north of the McArthur River Mine. Darby is interpreted to contain more than 25 kilometres of conductive strike length including the 8-kilometre-long 95B trend oriented parallel to the Cigar Lake – Tucker Lake trend. Historical drilling on 95B defined more than 25 metres of unconformity topography where a package of metasedimentary rocks hosting graphitic brittle structure, hydrothermal alteration, and weak uranium mineralization lies in fault contact with underlying granitic rocks. Only one drill hole completed along strike is interpreted to have intersected the optimal target in this prospective geological setting. Weak uranium mineralization has also been intersected in the northeast portion of Darby proximal to the Cigar Lake – Tucker Lake trend, and along the northern extension of the 4A trend north of Darby. Initial work is expected to include diamond drilling to follow-up historical drilling results and geophysical surveying to refine conductive drill targets.

The depth to the unconformity at Darby is between 480 and 650 metres.

The Packrat Project is located 28 kilometres east of the Cigar Lake Mine and 19 kilometres southwest of the Rabbit Lake Mill (Figure 4). Packrat covers a prominent magnetic break and basement-hosted resistivity low trend lying along interpreted magnetic lineaments related to the Cigar Lake – Tucker Lake magnetic low trend. Limited historical drilling on Packrat which targeted the resistivity low trend and magnetic break intersected weak uranium mineralization and zones of structural disruption and alteration of basement rocks. Initial work at Packrat is expected to include compilation and reinterpretation of historical geophysical and drilling data.

The depth to the unconformity at Packrat is less than 100 metres.