Murphy Lake North
Following up mineralization intersected within 5 kilometres of the world class Hurricane deposit.
why murphy lake north?
Murphy Lake North (MLN) is Cosa's highest priority in the eastern Athabasca Basin, Saskatchewan, and the most advanced of the projects secured through Cosa's strategic collaboration with Denison Mines, one of the Basin's most established uranium developers.
Located just 2.7 kilometres east of the Hurricane deposit, the world's highest-grade indicated uranium resource which Cosa’s management team is credited with discovering, drilling at MLN intersected uranium mineralization roughly one year after acquiring the project. The geology at MLN shares a compelling resemblance with that underpinning eastern Athabasca uranium deposits.
While at IsoEnergy, Cosa’s management team acquired the Larocque East project and went on to discover and delineate the Hurricane deposit. We’re applying that experience to exploring MLN.
Winter 2026 Drill Program
Winter drilling at MLN followed up structure and alteration intersected at the Cyclone trend in summer 2025. Three of five winter 2026 drill holes intersected uranium mineralization in two discrete zones, including up to 5.0 metres of 0.55% U₃O₈ including 0.5 metres of 1.7% U₃O₈ in drill hole MLN26-013 (see Cosa’s news release dated May 26, 2026).
Mineralization is within an open-ended corridor of intense structure and alteration and is polymetallic, a typical trait of many eastern Athabasca deposits including Hurricane, Cigar Lake, and Key Lake.
| Hole ID | From (m) | To (m) | Length (m) | Radioactivity¹, ² (CPS) | U₃O₈ % | Ni % | Co % | Orientation (Azi./Dip) | Location |
|---|---|---|---|---|---|---|---|---|---|
| MLN26-013 | 306.5 | 307.0 | 0.5 | >350 | 0.02 | 0.09 | 0.02 | 166° / -60° | |
| and | 307.5 | 308.0 | 0.5 | >1,000 | 0.25 | 0.26 | 0.04 | ||
| and | 308.5 | 313.5 | 5.0 | >1,000 | 0.55 | 4.09 | 1.73 | ||
| including | 310.5 | 313.0 | 2.5 | >5,000 | 0.95 | 4.50 | 2.29 | ||
| including | 310.5 | 311.0 | 0.5 | >13,000 | 1.70 | 6.01 | 2.50 | ||
| MLN26-014 | 278.3 | 278.8 | 0.5 | 350 | 0.04 | 0.09 | 0.04 | 170° / -75° | Section 3200E |
| MLN26-015 | No significant radioactivity | 000° / -90° | Section 3200E | ||||||
| MLN26-016 | 286.5 | 287.5 | 1.0 | >350 | 0.04 | 0.07 | 0.04 | 165° / -65° | Section 3200E |
| MLN26-017 | No significant radioactivity | 000° / -90° | Section 3200E |
- Radioactivity is total gamma from drill core measured with an RS-125 hand-held spectrometer
- Measurements of total gamma from drill core are an indication of uranium content but may not correlate with chemical assays
- Radioactivity previously released
Murphy Lake North Geochemical Assays
Chemical assays confirm uranium mineralization is the source of anomalous radioactivity intersected in three of five winter drill holes at the Murphy Lake North Joint Venture announced April 13, 2026 (Table 1, Figures 2 and 3). The strongest uranium mineralization is in MLN26-013, which intersected up to 1.7% U3O8 over 0.5 metres (310.5 – 311.0 metres) within a broader interval averaging 0.55% U3O8 over 5.0 metres (308.5 – 313.5 metres). Like sandstone hosted uranium deposits such as Hurricane, Key Lake, and Cigar Lake, the mineralization is polymetallic and includes significant quantities of nickel and cobalt.
The 1.0 metre mineralized interval directly below the unconformity in MLN26-016 is immediately north of the strongest basement faulting intersected at Cyclone and 40 metres north of the nearest hole on section, suggesting a potential near-miss of the ideal target with significant space for additional mineralization (Figure 3).
All mineralized intersections remain open along strike for at least 600 metres to the east and 600 metres to the west.
Planned Summer Drilling
Summer drilling at Murphy Lake North is expected to comprise approximately 15 drill holes totaling 6,000 metres focused on following up
uranium mineralization intersected during winter 2026 which is open along strike for 600 metres in both directions. Drilling on section 3200E (Figure 2) will target major faults with alteration which remain untested at the unconformity, including the area south of mineralized drill hole MLN26-016 where mineralization is open for 40 metres to the south (Table 1, Figure 3). Drilling on 3200E will be followed by progressive step outs along strike. Additional compelling targets have been generated 600 metres to the east and 600 metres to the west by reinterpreting summer 2025 drilling results in the context of the winter 2026 results.