IsoEnergy Intersects Strongly Elevated Radioactivity in Multiple Holes Immediately Along Strike of Hurricane and In Step-Out Target Area D, 2.8 km East

IsoEnergy Intersects Strongly Elevated Radioactivity in Multiple Holes Immediately

Along Strike of Hurricane and In Step-Out Target Area D, 2.8 km East

Toronto, ON, April 23, 2025 – IsoEnergy Ltd. (“IsoEnergy” or the “Company”) (TSX: ISO; OTCQX: ISENF)

is pleased to announce the completion of its winter drilling program at the Larocque East Project (the

“Project”), located in the eastern Athabasca Basin. The Company successfully completed 17 diamond drill

holes, totaling 6 ,396 m, along the Larocque Trend (“ Larocque Trend”), an important regional structure

that hosts the Hurricane Deposit (“Hurricane” or the “Deposit”) containing a current Indicated Mineral

Resource of 48.6 Mlbs at 34.5% U 3O8 and an Inferred Mineral Resource of 2.7 Mlbs at 2.2% U 3O8 (See

“Qualified Person Statement” below ). The Larocque Trend also hosts other notable high -grade

occurrences including those on Cameco and Orano’s Dawn Lake joint venture. The Company’s d rilling

intersected strongly elevated radioactivity, in five holes, along the eastern extensions of the Hurricane

Deposit main and south trends, as well as at Area D, 2.8 km east of Hurricane, highlighting the potential

for additional zones of uranium mineralization both immediately on strike of Hurricane and regionally

along the 9 km of the Larocque Trend on the Project.

Highlights

• Strong Radioactivity Intersected Along Hurricane Main and South Trends Confirm Structural

Continuity and Supports Resource Expansion Potential (Figure 1)

o Main Trend – Drilling along the projected extension of the H and I faults intersected strong

radioactivity, confirming potential continuity east of Hurricane. Hole LE25-194, located

80 m east of Hurricane, returned an average RS-125 reading on core of 3,100 cps over 0.5

m (Table 1) with a corresponding downhole probe maximum reading of 30,829 cps (Table

2). LE25-198 intersected up to 625 cps on core and 26,503 cps downhole probe 180 m

east of Hurricane.

o South Trend – Drilling along the projected extension of the J and K faults intersected

strong radioactivity, confirming potential continuity east of Hurricane. Hole LE25 -207,

located 240 m east of Hurricane, returned an average RS-125 reading on over 0.5 m on

core of 8,800 cps and a corresponding downhole probe maximum reading of 30,096 cps,

while LE25-210, drilled 480 m east of Hurricane, intersected up to 3,700 cps averaged

over 0.5 m on core and a corresponding downhole probe maximum reading of 20,280 cps.

• Best Radioactivity Intercept to Date in Area D Outside of Hurricane Confirms Regional Potential

o Hole LE25-202 returned an average RS-125 reading on over 0.5 m on core of 6 ,200 cps

and up to 28,782 cps downhole probe within that interval in Area D, a standalone zone

located 2.8 km east of Hurricane (Figure 2).

• Geochemical Results Pending as IsoEnergy Prepares for Summer Drilling

o All core samples from the winter drill holes have been submitted, with results pending.

o Summer drilling will look to build on winter results a s well as testing Target Areas E and

F, 6 to 9 km east of Hurricane. Details of the summer program will be provided in due

course.

• New Geophysical Interpretation Expands Larocque Trend Target Inventory

o A new geophysical model generated from joint inversion of historic electromagnetic and

resistivity survey data has highlighted a previously underexplored conductive trend 800

m north of the main Hurricane conductor. The 2,500 m trend has only been tested by two

historic drill holes, highlighting a compelling target for future testing (Figure 3).

Dr. Dan Brisbin, Vice President Exploration, commented, “The intersection of significantly elevated

radioactivity, and associated alteration, along two of the targeted Hurricane trends east of the resource

footprint and at Target Area D 2.8 km along trend from the Deposit highlight the potential for discoveries

both along extensions to structures that control high grade mineralization at Hurricane and in additional

target zones along the Larocque Trend. We look forward to resuming drilling this summer near Hurricane

and in greenfield target areas along a six-kilometre prospective segment of the Larocque Trend – including

at target areas E and F, where we decided to defer drilling until summer due to difficult ground conditions

this winter”.

Figure 1– Location of winter 2025 drill holes with respect to the Deposit resource footprint (blue) and

the ANT seismic low velocity zone in which the Deposit occurs, and projected Hurricane

mineralization-controlling fault zones. RS-125 values are highest averages over 0.5 m intervals.

Figure 2 – Location of 2025 target areas and winter drill holes along the Larocque Trend, including drill

holes in Target Area D, located 2.8 km east of the Deposit. In addition to targets near the Deposit,

greenfield potential will be tested this summer in areas D, E and F along a six-kilometre segment of

the Larocque Trend. RS-125 values are highest averages over 0.5 m intervals.

Table 1: Drill hole summary and RS-125 spectrometer results for holes with >350 cps.

Figure 3 – Joint resistivity – electromagnetic inversion model of the Larocque East project completed

by Convolutions Geoscience and Computational Geosciences that highlights an untested 2,500m

Hole ID Target Area  Az  Dip DH Depth (m) UNCO (m) HoleID From To Length Average

CPS

LE25-194 316 316.5 0.5 2,000

LE25-194 316.5 317 0.5 3,100

LE25-194 317 317.5 0.5 1,185

LE25-194 317.5 318 0.5 645

LE25-194 318 318.5 0.5 480

LE25-194 318.5 319 0.5 640

LE25-194 319 319.5 0.5 480

LE25-197 Hurricane 280 -89.9 350.0 332.5 LE25-197 330.5 331 0.5 360

LE25-198 314.5 315 0.5 425

LE25-198 315 315.5 0.5 625

LE25-198 315.5 316 0.5 370

LE25-202 286.5 287 0.5 360

LE25-202 287 287.5 0.5 325

LE25-202 288.5 289 0.5 825

LE25-202 289 289.5 0.5 6,200

LE25-202 289.5 290 0.5 1,600

LE25-202 290 290.5 0.5 880

LE25-202 290.5 291 0.5 385

LE25-207 323 323.5 0.5 800

LE25-207 323.5 324 0.5 4,600

LE25-207 324 324.5 0.5 600

LE25-207 325.5 326 0.5 500

LE25-207 326 326.5 0.5 1,000

LE25-207 326.5 327 0.5 650

LE25-207 327 327.5 0.5 350

LE25-207 328 328.5 0.5 8,800

LE25-207 328.5 329 0.5 1,000

LE25-210 307.5 308 0.5 380

LE25-210 311 311.5 0.5 360

LE25-210 317 317.5 0.5 350

LE25-210 319 319.5 0.5 900

LE25-210 319.5 320 0.5 400

LE25-210 320 320.5 0.5 1,200

LE25-210 320.5 321 0.5 400

LE25-210 321 321.5 0.5 850

LE25-210 321.5 322 0.5 650

LE25-210 323.5 324 0.5 3,700

LE25-210 325 325.5 0.5 350

LE25-210 327 327.5 0.5 375

374.0 320.6

* Hand-held Spectrometer Results On Mineralized

Drillcore (>350 cps / >0.5 m minimum)

365.0 316.5

Drill Hole Information

022 -89.9

350.0 323.8

380.0 270.3

LE25-194 Hurricane 380.0 319.7

-89.9LE25-210 Hurricane 44.7

Hurricane 290

LE25-207 Hurricane -90.0

LE25-202 D

LE25-198

353.4 -60.2

-89.8

northern conductivity trend.

Hurricane Resource Expansion Drilling

A total of 13 holes were completed to test three interpreted structural trends at Hurricane (Figure 1). Four

holes (LE25-194, 195, 198, 203) were drilled to t est the projected eastern extension of the faults th at

control the main high -grade portion of Hurricane (the “Main Trend”). Seven holes (LE25-197, 199, 200,

201, 207, 208, 210) were drilled to test the projected extension of faults that control the Hurricane

southern high-grade lens (the “South Trend”). Two holes (LE25– 196, 205A) were drilled to test a structure

intersected in historic drill holes in the middle sandstone north of the Deposit at the unconformity (the

“North Trend”).

Main Trend Highlights

Hole LE25-194 test ed down-dip of structure and anomalous geochemistry intersected in LE21-89 and

LE21-95A (Figure 4). Hole LE25-194 intersected widespread moderate to strongly bleached core through

most of the sandstone. Strong pervasive bleaching, clay alteration and desilicification were intersected

below 295 m. Moderate hematite and grey alteration, typical of Hurricane were intersected immediately

above the unconformity associated with strongly elevated radioactivity over 3.5 m from 316.0 to 319.5 m

which included a 0.5 m long interval with an average RS-125 spectrometer value of 3 ,100 cps and a

corresponding 2PGA probe value of 30,829 cps. Mineralization styles include worm-rock replacement,

fault-controlled and disseminated.

Hole LE25-198 drilled 100 m east of hole LE25-194, intersected widespread bleaching throughout the

sandstone. Clay and limonite alteration, centered on a fault, were intersected from 259 to 263 m. A broad

structural zone with continuous strong bleaching, desilicification, and clay alteration is present below 287

m. Fault-controlled hydrothermal hematite and weak grey alteration were intersected approximately 10

m above the unconformity, indicating the hole overshot the ideal target. Strong pervasive limonite and

clay alteration continued to the unconfor mity at 316.5 m. The basement rock immediately below the

unconformity is moderately argillitized and chloritized, with above-background radioactivity as measured

on core and by downhole gamma probing extending from 314. 0 m in sandstone down to 321.1 m in

basement. Peak values recorded on drill core with the RS-125 spectrometer and with the 2PGA downhole

probe are 625 cps average over a 0.5 m interval and 26,503 cps respectively. Hole LE25-198 is interpreted

to have overshot the target, and potential for mineralization remains high to the north.

Hole LE25-203 tested north of hole LE25-194 and intersected strong bleaching, moderate clay and

desilicification centred on structural zones below 283 m. Fault -controlled hematite alteration was

intersected at 320.3 m. A peak of 4,809 cps was recorded on the 2PGA probe at 325.0 m, one metre below

the unconformity.

Figure 4 – Main Trend: Cross section through LE25-194 and LE25-203 on the East Trend looking east.

South Trend Highlights

Hole LE25-207 was drilled between holes LE21-101 and LE22-115A to test for continuity of mineralization.

Hole LE25-207 intersected moderate bleaching beginning at 245 m. Elevated radioactivity was intersected

within hematitic breccia at 293 m. Strong structurally controlled bleaching and moderate clay alteration

were observed from 301 m to the unconformity at 323.8 m, with significant core loss recorded from 308

to 323 m. Strongly elevated radioactivity was recorded over 6.0 m from 323.0 m in the sandstone to 329.0

m in the basement (Figure 5). The interval included RS-125 spectrometer and 2PGA probe values of 8,800

cps averaged over a 0.5 m interval and 30,096 cps, respectively.

Hole LE25-210 tested down -dip of the sandstone structure intersected in hole LE22-118A. Strong

bleaching, clay alteration, and desilicification were observed below 251 m. Weak to moderate fault -

controlled hematite alteration was intersected at 319.5 m and 323.6 m. Continuous radioactivity

exceeding 350 cps (RS -125) was intersected in sandstone at 319 m and extended into the basement to

324 m. The highest radioactivity measured on core of 3700 cps averaged over a 0.5 m interval and a

corresponding 2PGA downhole probe peak of 20,280 cps were recorded within a basement-hosted fault,

highlighting the potential for a basement extension of Hurricane.

Figure 5 – South Trend: Core photo of drill hole LE25-207 from 310 m to 333.5 m showing interval from

323.0 m to 329.0 m with elevated radioactivity up to 8800 cps averaged over 50 cm on the RS-125

spectrometer. The unconformity is at 323.8 m.

Larocque Trend Area D Drilling

Four holes (LE25-202, 204, 206 and 209) were completed in Area D this winter (Figure 2). Three holes on

one section in the northwest end of Target A rea D in which strongly anomalous radioactivity was

intersected are summarized below.

Hole LE25-202, the first drill hole on section (Figure 6), intersected weak to moderate bleaching in the

upper sandstone. In the l ower sandstone, b elow 206 m, alteration is moderate to strong with a broad

bleached, clay and desilicified zone centred on faults. Moderate to strong limonite in present over a 10 m

interval below 254 m. The hole intersected unconformity at 270.3 m and hematitic breccia immediately

below unconformity. A second hematitic fault was intersected at 282 m before the drill hole intersected

a moderately hematitic radioactive zone from 286.5 to 291.0 m. Blebs and fracture -hosted uranium

mineralization are associated with the highest RS-125 reading of 6200 cps over 0.5 m.

Hole LE25-204, drilled to the south and designed to test down dip of the LE25-202 intersection, intersected

broad bleaching throughout the sandstone. Moderate clay alteration and desilicification with significant

core loss were intersected below 245 m to unconformity at 262.9 m.

Hole LE25- 206 tested the up-dip projection of mineralized fault intersected in LE25 -202. LE25-206

intersected moderate bleaching throughout the sandstone. From 206 m to the unconformity at 253.2 m,

the drill hole intersected moderate to strong bleaching, strong clay and des ilicified zones centred on

faults. Moderate fault-controlled hematite and limonite occur below 224 m. The basal sandstone, below

248 m, is strongly argillitized and chloritized. Hole LE25-206 also intersected fault-controlled hematite in

basement from 257 to 263 m.

Figure 6 – Cross section through LE25-202, 204 and 206 on the west end of Target Area ‘D’ looking

east.