Vancouver, British Columbia--(Newsfile Corp. - October 1, 2025) - Cosa Resources Corp. (TSXV: COSA) (OTCQB: COSAF) (FSE: SSKU) ("Cosa" or the "Company") is pleased to report it has expanded its 100% owned Orbit Project ("Orbit" or the "Project") to cover coincident radon, helium, and hydrogen anomalies, and electromagnetic (EM) conductors. Orbit is located 21 kilometres south of Cameco's Key Lake Mill and historical Key Lake Mine in the southeastern Athabasca Basin region, Saskatchewan.

Highlights

• New claims cover radon, helium, and hydrogen occurrences and EM conductors

• Orbit is drill ready with near-surface drill targets in multiple areas

• Orbit now covers over 15,000 hectares with no encumbrances and no sandstone cover

• Planning underway for follow up in 2026

Andy Camichael, VP of Exploration, commented: "With no sandstone to inhibit the migration of pathfinder gases, we view remote sensing as having great potential to aid exploration at Orbit. Remote sensing identified two zones of coincident anomalous radon, helium, and hydrogen, including one zone later covered by targeted staking. Recent staking also added 3 kilometres of drill ready conductive strike length. We're pleased to have bolstered the target inventory of a Project located near highways, powerlines, permanent camp facilities, and the Key Lake uranium mill. Planning is underway for follow up in 2026."

Orbit Expansion and Remote Sensing

Cosa undertook remote sensing work to evaluate the area for radon, helium, and hydrogen which can be important pathfinders for uranium exploration as they may be produced by the radioactive decay of uranium.

Two areas of coincident radon, helium, and hydrogen were identified by remote sensing work (Figure 2). The ORS-1 target is in the northern portion of Orbit, measures up to 1,000 x 1,000 metres, and is predominantly located on land with portions extending onto small lakes. ORS-2 is located within newly staked lands, measures up to 750 x 600 metres, and is within a small lake with portions extending on to land. Both the ORS-1 and ORS-2 targets are within magnetic low zones, indicating they may be underlain by prospective metasedimentary basement rocks.

Recent staking also covered 3 kilometres of strike length of subparallel, northeast trending EM conductors defined by 2017 ground surveying (Figure 3). Several of these conductive features extend to the northeastern limit of the historical survey area, suggesting potential to extend these features with additional surveying.

Next Steps

Follow up work is expected to include ground-based gas surveys for radon, helium, and hydrogen. As the ORS-1 and ORS-2 anomalies lie outside the 2024 airborne EM and gravity gradient survey areas, additional airborne surveying may also be completed.

Figure 1 - Cosa's Eastern Athabasca Uranium Projects with Joint Venture Projects

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Figure 2 - New Orbit Staking and Pathfinder Gas Occurrences

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Figure 3 - New Orbit Staking Covering 2017 Ground Survey Conductors

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About Cosa Resources Corp.

Cosa Resources is a Canadian uranium exploration company operating in northern Saskatchewan. The portfolio comprises roughly 237,000 ha across multiple underexplored 100% 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 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 track 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. Drilling completed by Cosa in 2025 identified multiple zones of strong sandstone structure and alteration and weakly elevated radioactivity underlain by large graphitic structures rooted in basement rocks. The Company is planning additional follow up work in 2026.

Technical Disclosure

Historical geophysical results for Orbit were sourced from the (SMAD). SMAD sources relied on for this release include 74A13-0036 and MAW02156. Verification of historical geophysical results was limited to reviewing historical reports and interpretations authored by Professional Geoscientists and confirming the locations of geophysical survey grids from air photos.

Qualified Person

The Company's disclosure of technical or scientific information in this press release has been reviewed and approved by Andy Carmichael, P.Geo., Vice President, Exploration for Cosa. Mr. Carmichael is a Qualified Person as defined under the terms of National Instrument 43-101.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Cautionary Statements

This press release contains forward-looking information within the meaning of Canadian securities laws (collectively "forward-looking statements"). Forward-looking statements are typically identified by words such as: believe, expect, anticipate, intend, estimate, plans, postulate and similar expressions, or are those, which, by their nature, refer to future events. All statements that are not statements of historical fact are forward-looking statements. These forward-looking statements or information may relate to anticipated exploration, development and/or expansion activities, including exploration of the Company's current Projects; the collaboration with Denison, including the Joint Venture, and the anticipated benefits thereof; and the outlook regarding Cosa's business plans and objectives.

Such forward-looking information and statements are based on numerous assumptions, including among others, that the results of planned exploration activities are as anticipated, the cost of planned exploration activities are as anticipated, that general business and economic conditions will not change in a material adverse manner, that financing will be available if and when needed and on reasonable terms, that third party contractors, equipment and supplies and governmental and other approvals required to conduct Cosa's planned exploration activities will be available on reasonable terms and in a timely manner. Although the assumptions made by Cosa in providing forward-looking information or making forward-looking statements are considered reasonable by management at the time, there can be no assurance that such assumptions will prove to be accurate.

By their nature, forward-looking statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements, or other future events, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Such factors and risks include, among others: Cosa may require additional financing from time to time in order to continue its operations which may not be available when needed or on acceptable terms and conditions acceptable; Cosa may not be able to maintain compliance with its contractual obligations with third parties; Cosa may not be able to maintain compliance with extensive government regulation applicable to its operations; domestic and foreign laws and regulations could adversely affect Cosa's business and results of operations; the stock markets have experienced volatility that often has been unrelated to the performance of companies and these fluctuations may adversely affect the price of Cosa's securities, regardless of its operating performance; the ongoing military conflict in Ukraine, and other risk factors set out in Cosa's public disclosure documents.

The forward-looking information contained in this news release represents the expectations of Cosa as of the date of this news release and, accordingly, is subject to change after such date. Readers should not place undue importance on forward-looking information and should not rely upon this information as of any other date. Cosa does not undertake any obligation to update these forward-looking statements in the event that management's beliefs, estimates or opinions, or other factors, should change.

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