Cosa Announces Commencement of Winter 2026 Drilling Campaign on Joint Ventures with Denison Mines
Rhea-AI Summary
Cosa Resources (TSXV: COSA; OTCQB: COSAF) and Denison Mines (TSX: DML; NYSE: DNN) have begun winter 2026 drilling on the Darby joint venture, with Murphy Lake North (MLN) to follow. Cosa operates both projects and holds a 70% interest, Denison holds 30%.
Planned work includes ~2,500 metres at Darby to test 2025 relogging targets and ~1,200 metres at MLN to fill a 1,200‑metre lake-access drilling gap along the Cyclone trend.
Positive
- Darby drilling planned: 2,500 metres in winter 2026
- MLN follow-up drilling: 1,200 metres to test Cyclone trend gap
- Cosa is operator and holds a 70% interest in each joint venture
- Targets based on 2025 core relogging and anomalous uranium alteration
Negative
- MLN has a 1,200‑metre lake-access gap limiting summer drilling
- Drilling success depends on testing priority anomaly areas, not guaranteed
News Market Reaction
On the day this news was published, COSAF gained 10.35%, reflecting a significant positive market reaction.
Data tracked by StockTitan Argus on the day of publication.
Key Figures
Market Reality Check
Peers on Argus
Several uranium peers showed gains, with UUUU, NXE, UEC, LEU and URG up between 5.18% and 9.71%, and scanner names EU and UUUU also moving up. Despite this, the move in DNN is flagged as stock-specific rather than a confirmed sector-wide move.
Historical Context
| Date | Event | Sentiment | Move | Catalyst |
|---|---|---|---|---|
| Jan 21 | Drilling plans JV | Positive | +1.6% | Outlined winter 2026 drill programs at Darby and MLN joint ventures. |
| Jan 08 | Power line complete | Positive | +0.0% | Announced grid power via new 138kV line to future Phoenix mine site. |
| Jan 02 | Phoenix capex update | Positive | +13.9% | Reported Phoenix ISR readiness, updated <b>$600M</b> capex and funding position. |
| Dec 17 | New JV formations | Positive | -4.6% | Closed Skyharbour deal forming four joint ventures near Wheeler River. |
| Dec 04 | Impact Benefit deal | Positive | +5.2% | Signed IBA and exploration agreement supporting Wheeler River development. |
Recent DNN news has mostly seen positive or neutral price reactions, with one notable negative divergence.
Over the past two months, Denison’s news has focused on advancing its uranium portfolio and partnerships. Updates included Phoenix construction readiness with a $600 million capex plan and over $700 million in cash, uranium and investments (Jan 2), grid power availability for Phoenix (Jan 8), and multiple Wheeler River–area joint ventures and agreements in Dec 2025. A Jan 21 release also detailed winter 2026 drilling plans with Cosa, which today’s commencement announcement follows operationally.
Market Pulse Summary
The stock surged +10.3% in the session following this news. A strong positive reaction aligns with DNN’s established uptrend and the pattern of constructive responses to project-advancement news. The drilling commencement follows prior disclosures of winter 2026 plans for the Darby and MLN joint ventures, reinforcing continuity rather than a new strategic shift. With short interest around 7.73%, past gains and positioning could influence how durable such strength became after similar operational updates.
Key Terms
graphitic basement faults technical
sandstone alteration technical
AI-generated analysis. Not financial advice.
Vancouver, British Columbia--(Newsfile Corp. - January 28, 2026) - Cosa Resources Corp. (TSXV: COSA) (OTCQB: COSAF) (FSE: SSKU) ("Cosa" or the "Company") is pleased to announce drilling has commenced at the Company's Darby ("Darby") project, with drilling at Murphy Lake North ("MLN") to follow (Figure 1). Darby and MLN are joint ventures (the "Joint Venture") between Cosa and Denison Mines Corp. ("Denison") (TSX: DML) (NYSE American: DNN) and are located 10 kilometres west of Cameco's Cigar Lake Mine and three kilometres east of IsoEnergy's Hurricane Deposit, respectively, in the eastern Athabasca Basin, Saskatchewan. Cosa is the operator of both projects and holds a
Winter Drilling
Approximately 2,500 metres are planned at Darby in winter 2026 to test initial priority targets identified by Cosa's 2025 core relogging and reinterpretation program. Priority targets are the immediate vicinities of drill holes which intersected zones of coincident sandstone alteration and anomalous1 uranium content proximal to significant graphitic basement faults. Up to four initial target areas will be evaluated during winter 2026.
Drilling plans at MLN comprise approximately 1,200 metres and will follow up summer 2025 results at the Cyclone trend where broad zones of structure and alteration were intersected over a two-kilometre strike length. Drilling will target a 1,200-metre gap in existing drilling where a lake prevents summer access. Drilling will also test a potential trend parallel to and approximately 100 metres south of Cyclone interpreted from intensely graphitic rocks and faulting intersected in the basement of MLN25-007.
For further details on winter 2026 drill targets, refer to Cosa's news release dated January 21, 2026.
About Darby
Located 10 kilometres west of the Cigar Lake Mine, Darby contains multiple prospective conductive trends and several historical intersections of weak uranium mineralization (Figure 1). Historical drilling demonstrates that many of these trends are highly prospective for uranium deposits characteristic of the eastern Athabasca Basin, yet most of the strike length has not been effectively evaluated. Work by Cosa in 2025 prioritized these trends and identified several historical drill holes with results that suggest proximity to uranium mineralization (See Cosa's news releases dated October 24, 2025, and January 21, 2026). Darby was last drilled in 2009.
About Murphy Lake North
MLN covers a portion of the Larocque Lake trend and is located 2.7 kilometres east of the Hurricane deposit (Figure 1). Hurricane is the world's highest-grade indicated uranium resource and was discovered and delineated for IsoEnergy Ltd. by current members of Cosa's team. The Larocque Lake trend also hosts the high-grade Larocque Lake Zone, Yelka Prospect, and Alligator Lake Zone. MLN contains the along-strike extension of basement geology underlying the Hurricane deposit (the Hurricane trend), as well as a parallel conductive trend to the south (the Cyclone trend). Drilling by Cosa in 2025 intersected zones of sandstone alteration and structure associated with graphitic basement structures along both trends. Following up these positive results is the primary 2026 objective at MLN.
1 - When analyzed using SRC's partial digestion and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) method, Cosa considers uranium concentrations in the Athabasca sandstone greater than 0.5 ppm to be elevated, greater than 1.0 ppm to be anomalous, and greater than 4 ppm to be strongly anomalous.
Figure 1 - Cosa's Eastern Athabasca Uranium Projects with Joint Venture Projects
To view an enhanced version of this graphic, please visit:
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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
In January of 2025, the Company entered a transformative strategic collaboration with Denison Mines (TSX: DML) (NYSE American: DNN) that has secured 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 track 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 held key roles in the founding of both NexGen and IsoEnergy.
The Company's focus throughout 2026 is drilling at the Darby and MLN 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 will evaluate target areas with anomalous uranium, clay alteration, and historical mineralization intersected nearby. Drilling at MLN will follow up 2025 drilling which intersected broad zones of structurally controlled alteration over roughly 2 kilometres of strike length.
Technical Disclosure
Historical drilling and geophysical results for Darby and MLN were sourced from the Saskatchewan Mineral Assessment Database (SMAD). SMAD sources for Darby include file numbers 74H14-0021, 74H14-0023, 74H15-0041, 74H15-0053, 74H15-0055, 74H15-0056, 74H15-0066, 74H15-0067, 74I02-0031, 74I02-0042, 74I02-0053, 74I02-0080, 74I02-0095, and MAW00516. Some confidential data and reports not presently available via SMAD were supplied to Cosa by Denison. SMAD sources for MLN and adjacent projects include file numbers 64L05-0161, 64L05-0180, 74I-0060, 74I-0066, 74I-0067, 74I01-0114, 74I08-0056, 74I09-0053, 74I09-0057, 74I09-0061, 74I09-0064, 74I09-0066, 74I09-0071, 74I09-0077, 74I09-0079, 74I09-0087, 74I09-0088, 74I09-0090, 74I09-0091, 74I09-0092, 74I09-0098, MAW00510, MAW01939, MAW02327, MAW02599, and MAW02395. Data and reports related to the 2020 ground EM survey completed by Denison are not presently available via SMAD and were supplied to Cosa by Denison.
Verification of historical drilling results included confirming historical drill hole collar locations from air photos and ground checking selected collars with a handheld GPS unit. Basement and lower sandstone sections from most historical drill holes were relogged in 2024 and 2025 by Cosa. For Darby, verification of geochemical results for drill holes completed between 2008 and 2010 was facilitated by the reissuance of analytical certificates to Cosa by the Saskatchewan Research Council (SRC). Cosa thanks the SRC for its valued assistance in increasing confidence in the historical dataset.
Verification of historical geophysical results included confirming the locations of geophysical survey grids from air photos, compiling survey data and interpretations, and evaluating whether interpreted geophysical results could be reasonably explained by historical and current drilling results. For MLN, Cosa engaged a consultant to re-interpret historical geophysical surveys to validate selected previous interpretations.
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. This news release refers to neighbouring properties in which the Company has no interest. Mineralization on those neighbouring properties does not necessarily indicate mineralization on the Company's properties.
Contact
Keith Bodnarchuk, President and CEO
info@cosaresources.ca
+1 888-899-2672 (COSA)
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.
To view the source version of this press release, please visit https://www.newsfilecorp.com/release/281854
FAQ
What drilling is Cosa planning at Darby in winter 2026 (DNN)?
How much drilling will Cosa conduct at Murphy Lake North (MLN) and why?
What ownership and operator roles apply to the Darby and MLN joint ventures with Denison (DNN)?
What are the geological targets driving Cosa's winter 2026 drilling program?
Will winter drilling at MLN address summer access limitations near Cyclone (DNN)?
How many initial target areas will Cosa evaluate at Darby during winter 2026?
