Toronto – September 10, 2026 -- IsoEnergy Ltd. (NYSE American: ISOU; TSX: ISO) intersected the strongest radioactivity measured to date along the Hurricane South Trend, with three drill holes returning readings above 35,000 counts per second (cps) during a summer program at its Larocque East uranium project in Saskatchewan.
Summer drilling expands to 10,159 metres after early results exceed expectations
The company completed 26 holes totaling 10,159 metres this summer, expanding an original plan of 8,000 metres across 20 holes. Combined with winter drilling, year-to-date totals reached 16,963 metres across 43 holes at Larocque East, which hosts the high-grade Hurricane deposit.
Eighteen of 26 holes hit elevated radioactivity along 600-metre strike length
Eighteen of the 26 summer holes returned intervals above the 350 cps cut-off threshold over 0.5 metres, with 13 holes recording 1,000 cps or greater. Three holes exceeded 35,000 cps, the highest radioactivity measured on the South Trend to date.
Drill hole LE26-250 extends mineralization 75 metres beyond existing deposit footprint
LE26-250, drilled 75 metres east of winter hole LE26-248 and outside the current Hurricane resource boundary, intersected 11,075 cps over 3.5 metres, including 43,160 cps over 0.5 metres. Winter hole LE26-248 had returned 4.21% U3O8 over 3.5 metres, including 11.6% U3O8 over 1.0 metre.
LE26-273, drilled 11 metres west of LE26-248 within the southern portion of the deposit footprint, returned 14,135 cps over 3.0 metres, including 36,292 cps over 1.0 metre. LE26-254, positioned 510 metres east of the existing footprint and 28 metres west of winter hole LE26-234, intersected 10,110 cps over 2.0 metres, including 35,900 cps over 0.5 metres.
Hurricane deposit currently holds 48.6 million pounds U3O8 in indicated resources
The Hurricane deposit hosts an Indicated Mineral Resource of 48.6 million pounds U3O8 at a grade of 34.5%, plus an Inferred Resource of 2.7 million pounds U3O8 at 2.2%. The project sits approximately 40 kilometres northwest of the McClean Lake mill, with mineralization beginning at roughly 325 metres depth. Hurricane lies on the Larocque Trend, the same regional structure hosting high-grade occurrences at Cameco and Orano's Dawn Lake joint venture.
Wildfire forces temporary shutdown before crews resume expanded program
Dan Brisbin, Vice President Exploration, said the project team completed the expanded summer program despite a temporary demobilization in June due to a nearby wildfire. Nearly half of all 2026 drill holes intersected elevated radioactivity, he noted, with assay results pending to guide 2027 target definition.
All summer program samples have been submitted to SRC Geoanalytical Laboratories, with uranium geochemistry results expected to refine the geological model ahead of 2027 exploration planning.