Mr. Keith Bodnarchuk reports

COSA APPOINTS DAVID CATES, PRESIDENT AND CEO OF DENISON MINES, AS STRATEGIC ADVISOR

Cosa Resources Corp. has appointed David Cates as strategic adviser to the company. Mr. Cates is currently a director, president and chief executive officer of Denison Mines Corp. (Toronto Stock Exchange: DML) (NYSE American: DNN). Cosa owns a 70-per-cent interest in and operates multiple joint ventures with Denison Mines: Murphy Lake North, Darby and Packrat.

Keith Bodnarchuk, president and chief executive officer of Cosa, commented: "I have known and respected David for almost 15 years, having previously worked for him during my time at Denison. Since finalizing the transformative property acquisition with Denison earlier this year, we have been fortunate to work closely with David in support of the growing collaboration between Cosa and Denison. We thank David for his willingness to join us in the official capacity of strategic adviser, and we look forward to continuing to work together with David and the entire Denison team as we prepare for and commence an exciting exploration program in early 2026."

David Cates, president and chief executive officer of Denison and strategic adviser to Cosa, commented: "Cosa's leadership and technical team are amongst the best in the uranium exploration sector, and are well known to me from their past time working with Denison. It has been energizing to reconnect with the Cosa team since our collaboration commenced early this year. With the next round of exploration at the Darby and Murphy Lake North joint venture properties planned for the winter of 2026, it is an exciting time for me to join the Cosa team in an official capacity. With Denison's core focus on completing the final stages of permitting and future construction of our Phoenix in situ recovery uranium mine, I am pleased to support Cosa's complementary exploration efforts in the pursuit of a new meaningful uranium discovery in the eastern portion of the Athabasca basin."

Strategic adviser

Mr. Cates is a chartered professional accountant (CPA, CA) and holds master of accounting (MAcc) and honours bachelor of arts (BA) degrees from the University of Waterloo. Mr. Cates has extensive expertise in the Canadian and international uranium mining industry from nearly two decades of senior management and financial experience in various roles with Denison. Mr. Cates was appointed president and chief executive officer of Denison in 2015, having previously served as the company's vice-president, finance and tax, and chief financial officer. Prior to joining Denison in 2008, Mr. Cates held positions at Kinross Gold Corp. and PwC LLP.

Leading Denison through the innovative deployment of the ISR mining method at its flagship Wheeler River project, as well as project permitting and finance efforts, Mr. Cates's experience is unparalleled. As an adviser to Cosa, Mr. Cates offers invaluable insight into the mine development process, community relations efforts, corporate strategy and finance, as well as the overall uranium market.

About Cosa Resources Corp.

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

In January of 2025, the company entered a transformative strategic collaboration with Denison that has secured Cosa access to 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 record of success in Saskatchewan. In 2022, members of the Cosa team were awarded the AME Colin Spence Award for the discovery of the Hurricane uranium deposit. 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 focus throughout 2026 is expected to be exploration drilling at the Darby and Murphy Lake North projects in the eastern Athabasca basin. Both projects are operated by Cosa and are 70/30 joint ventures between Cosa and Denison, respectively. Drilling at Darby is planned to test priority targets identified by thorough review of historical data and drill core, and are planned to target areas with anomalous uranium, clay alteration and historical mineralization intersected nearby. Drilling at Murphy Lake North is expected to follow up 2025 drilling which intersected broad zones of structurally controlled alteration over roughly two kilometres of strike length.

Marketing services agreement

Additionally, the company announces it has entered into a marketing services agreement with Oak Hill Financial Inc., an arm's-length party to the company. Oak Hill is to provide certain marketing, investor relations and advisory services to Cosa with the primary objective of increasing stakeholder communication and expanding market awareness of the company and its ongoing exploration operations.

No securities or other share-based incentives of Cosa are being granted to Oak Hill under the terms of the agreement. To the knowledge of Cosa, neither Oak Hill nor any of its directors, officers or employees currently own any securities of Cosa. Oak Hill has committed to comply with all applicable securities laws and the policies of the TSX Venture Exchange in providing the services.

The agreement is subject to TSX-V approval and shall be for an initial two-month term, for a monthly fee of $10,500, plus applicable taxes, which may be automatically renewed for successive one-month periods.

Oak Hill is a provider of investor relations and capital markets advisory services with an office located at 2 Bloor St. West, suite 2900, Toronto, Ont., M4W 3E2.

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