Announcement • 3h
Cosa Resources Corp Commences Largest Drill Program to Date At Murphy Lake North Uranium Joint Venture with Denison Mines
Cosa Resources Corp. had commenced drilling at the Company's Murphy Lake North project. MLN is a joint venture between Cosa and Denison Mines Corp. and is located three kilometres east of IsoEnergy's Hurricane deposit. Cosa is the project operator and holds a 70% interest with Denison holding a 30% interest. Drilling will evaluate potential extensions of the Cyclone uranium mineralization intersected during the winter program which is open along strike for 600 metres in both directions and located only 265 metres below surface. Drilling to comprise approximately 6,000 metres in 15 drill holes and represents the largest drill program in the history of the Company. Denison participating in funding 2026 exploration at MLN to maintain its 30% interest. Summer drilling at Murphy Lake North is expected to comprise approximately 15 drill holes totaling 6,000 metres. Drilling will focus on following up uranium mineralization intersected during winter 2026 which is open along strike for 600 metres in both directions. Drilling on section 3200E 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. Drilling on 3200E will be followed by progressive step outs along strike as warranted. Additional compelling drill 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. MLN Winter 2026 Assay Results: HoleID MLN26-013, From 306.5m To 307.0m, Length 0.5m, Radioactivity >350, U3O8 0.02%, Ni 0.09%, Co 0.02%, Orientation 166o /-60o, Location Section 3200E; and 307.5m To 308.0m, Length 0.5m, Radioactivity >1,000, U3O8 0.25%, Ni 0.26%, Co 0.04%; and 308.5m To 313.5m, Length 5.0m, Radioactivity >1,000, U3O8 0.55%, Ni 4.09%, Co 1.73%; incl. 310.5m To 313.0m, Length 2.5m, Radioactivity >5,000, U3O8 0.95%, Ni 4.50%, Co 2.29%; incl. 310.5m To 311.0m, Length 0.5m, Radioactivity >13,000, U3O8 1.70%, Ni 6.01%, Co 2.50%. MLN26-014, From 278.3m To 278.8m, Length 0.5m, Radioactivity 350, U3O8 0.04%, Ni 0.09%, Co 0.04%, Orientation 170o /-75o, Location Section 3200E. MLN25-015, No significant radioactivity, Orientation 000o /-90o, Location Section 3200E. MLN26-016, From 286.5m To 287.5m, Length 1.0m, Radioactivity >350, U3O8 0.04%, Ni 0.07%, Co 0.04%, Orientation 165o /-65o, Location Section 3200E. MLN26-017, No significant radioactivity, Orientation 000o /-90o, Location Section 3200E. MLN covers a portion of the Larocque Lake trend and is located 2.7 kilometres east of the Hurricane deposit. 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). Cosa's winter 2026 drill program intersected several metres of basement hosted uranium mineralization within a broader zone of strong structure and alteration at the Cyclone trend. Following up these results is the primary objective for the remainder of 2026 at MLN. Historical drilling and geophysical results for MLN were sourced from the Saskatchewan Mineral Assessment Database (SMAD). 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. 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. Anomalous radioactivity in drill core was measured by removing 0.5 metre intervals of drill core to an area of background radioactivity and scanning it with an RS-125 handheld spectrometer to determine average CPS. Sampling was completed by collecting half-core splits measuring 0.5 metres in length with intervals that align with radioactive measurement intervals. Samples were transported to SRC Geoanalytical Laboratories (SRC) in Saskatoon, Saskatchewan (ISO/IEC 17025:2005 accredited) for U3O8 assay and multielement analysis. Cosa inserts certified reference material (CRM) blanks and standards into the split core sample series as a QA/QC measure. SRC conducts a QA/QC programme which includes repeat analyses and insertion of CRM standards CAR218, BL4A, and BL2A. SRC's CRM results are verified by Cosa staff. U3O8 assay results are compared to RS-125 handheld scintillometer readings and downhole gamma probe results to verify chemical assays and measured radioactivity align. 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.