Cosa Intersects up to 1.7% U3O8 Within Interval of 5.0 m of 0.55% U3O8 at Murphy Lake North Joint Venture with Denison Mines
Cosa’s first assay from Cyclone confirms high-grade uranium and surprise nickel/cobalt, but a maiden resource is a long way off.
The May 26, 2026, release provides first chemical assays from the winter 2026 drilling at the Murphy Lake North (MLN) joint venture (70% Cosa / 30% Denison Mines). The highlight is hole MLN26‑013, which yielded 5.0 m averaging 0.55 % U₃O₈, including a higher‑grade core of 2.5 m at 0.95 % U₃O₈ and a 0.5 m interval at 1.7 % U₃O₈. Importantly, the mineralization is polymetallic – the same interval also contains 4.1 % Ni and 1.7 % Co, a characteristic shared by major deposits such as Hurricane, Key Lake, and Cigar Lake. The zone is shallow (~265 m vertical depth), remains open for 600 m in both directions along strike, and is hosted within a >100 m‑wide structural corridor called Cyclone. The joint‑venture is now finalizing its largest drill program to date, expected to start in mid‑June 2026.
The assay results confirm the anomalous radioactivity reported earlier (March 24 and April 13, 2026) and add the critical nickel‑cobalt by‑product dimension. Only one hole (MLN26‑013) delivered the high‑grade intercept; the other two holes with radioactivity (MLN26‑014, 016) reported weak uranium (<0.05 % U₃O₈). Summer drilling will follow up aggressively.
The market already knew MLN26‑013 contained a 5.0 m zone of >1,000 cps radioactivity, so a significant uranium intersection was widely expected. Nonetheless, the assay release is genuinely positive and material for three reasons:
- Grade confirmation exceeds typical “grassroots” expectations – 0.55 % U₃O₈ over 5 m, with a 0.5 m pod at 1.7 %, is high‑grade for an open Athabasca trend and comparable to early discovery holes at Hurricane and Gryphon.
- Polymetallic character (4.1 % Ni, 1.7 % Co) adds a valuable by‑product credit that is rare in uranium projects; this could meaningfully improve future project economics and draws a direct analogy to the world‑class Cigar Lake deposit.
- The “open” nature of the trend – 600 m of untested strike in both directions – substantially increases the discovery optionality beyond a single hole.
Counterpoints: the assays came from one good hole; the other two holes with radioactivity returned uneconomic grades. The stock has already rallied from ~$0.35 in mid‑March to a high of $0.79 before settling at $0.68, pricing in a decent amount of optimism. The summer drill program is now the critical next catalyst.
Overall, the news moves the needle and merits a “Material – Positive” rating because it validates a new mineralized system with tier‑one potential and introduces a significant polymetallic kicker that was not fully anticipated.
Cosa Resources is a uranium exploration company focused on the eastern Athabasca Basin, Saskatchewan. It employs a joint‑venture model with Denison Mines (30% partner) on three key projects – Murphy Lake North, Darby, and Packrat – and holds several 100%‑owned projects (Ursa, Orion, Orbit). The company also has option agreements with Traction Uranium (Aurora) and Global Uranium (Astro) where partners fund exploration to earn up to 80% interest.
The flagship project is Murphy Lake North (MLN), located just 2.7 km east of IsoEnergy’s Hurricane deposit. The 2025–2026 winter program discovered a shallow, high‑grade uranium‑nickel‑cobalt system at the Cyclone trend, comparable to some of the Basin’s best deposits. The project is drill‑ready and fully permitted for year‑round work.