Saturday, September 19, 2026
MiningNewsTerminal
Saturday, September 19, 2026 Admin

ISO.TO ·

IsoEnergy Commences Athabasca Basin Winter 2025 Exploration Program

Exploration Programs

IsoEnergy Commences Athabasca Basin Winter 2025 Exploration Program

Toronto, ON, January 14, 2025 – IsoEnergy Ltd. (“IsoEnergy” or the “Company”) (TSX: ISO; OTCQX:

ISENF) is pleased to announce the commencement of its 2025 winter exploration program in the eastern

Athabasca Basin, Canada (Figure 1) designed to build on the Company’s successful 2024 season. A total of

8,800 metres of drilling are planned on the Larocque East project, which contains the high-grade Hurricane

deposit, with mobilization to the project underway. The focus of the program is twofold , with drilling to

test resource expansion potential near the Hurricane deposit and the evaluation of greenfield targets

along the Larocque Trend (“Larocque Trend”) east of Hurricane. Geophysical surveys are also planned on

the Hawk, Evergreen and East Rim projects to advance these early-stage projects to the drill ready stage.

A total budget of $ 5.3 million has been approved for the winter exploration program s in the Athabasca

Basin.

Highlights

• Hurricane Deposit Resource Expansion

o Approximately 2,800 metres of drilling in s even holes will target gaps in historic drilling

near the Hurricane deposit and 2024’s Target Area B (Figure 2).

o Drilling will test areas where prior results indicate geochemical anomalies and alteration

associated with fault extensions that control mineralization within the Hurricane resource

(Figure 2).

• Greenfield Targets Along the Larocque Trend

o Up to 6,000 metres of drilling in 15 holes will test a six-kilometre segment of the Larocque

Trend east of the Hurricane deposit (Figures 3 and 4).

o Drilling will focus initially on three target areas (D, E, and F) identified through 2024’s

integration of geophysical and geochemical data. The trend on which these target areas

lie extends eastward on to IsoEnergy and Purepoint Uranium’s joint venture announced

late last year (Figure 2).

• Geophysical Surveys on Highly Ranked, Early-Stage Projects

o Ground geophysical surveys are planned on the East Rim , Evergreen, and Hawk projects

(Figure 1) to advance targets to the drill-ready stage.

Dan Brisbin, Vice President of Exploration, stated , “We are eager to launch our winter exploration

program, which includes testing deposit expansion targets around the margins of the Hurricane deposit

and exploring for new deposits along the highly prospective Larocque Trend. Targets on this corridor were

identified through a comprehensive integration of drill hole geology, geochemistry, alteration mineralogy,

and geophysical data, including electromagnetic, DC resistivity, and ANT surveys. The approach builds on

the understanding that Athabasca uranium deposits often consist of multiple zones distributed along

trends several ki lometres in length, suggesting the potential for additional discoveries beyond the

Hurricane deposit. Drilling in the easternmost target areas of the Larocque East project will also enhance

our understanding of favo urable structural trends extending onto the Turnor Lake project to the east,

where our joint venture partner, Purepoint Uranium, is advancing plans for future drilling.”

Figure 1 – Location of IsoEnergy’s exploration projects in the eastern Athabasca Basin.

Resource Expansion Targets at Hurricane

Drilling will commence with testing resource expansion targets near the Hurricane deposit and between

it and 2024 Target Area B (Figure 2). Review of 2024 and past drill results has highlighted gaps in drill hole

patterns where nearby holes intersected indicative geochemistry and alteration along projected

extensions of faults which control mineralization within the Hurricane resource.

Historical results on the south side of the Hurricane deposit are encouraging, with drill hole LE22 -115A

intersecting 1% U₃O₈ over 2.0 m and LE21-101 intersecting 0.6% U₃O₈ over 4.5 m, including a higher-grade

interval of 3.1% U₃O₈ over 0.5 m (see November 16, 2021, and July 15, 2022, press releases) . These

intersections are proximal to a fault that controls a southern high-grade lens in the resource, underscoring

the structural influence on mineralization and opening the possibility to extend the existing lens or identify

additional mineralized lenses along this southern fault outside of the existing resource footprint.

Holes from the east end of the Hurricane resource footprint and to the east end of ambient noise

tomography (“ANT”) target Area B drilled in 2024 have strong illite clay alteration and uranium partial

(“Up”) geochemical signatures, and structural disruption so additional holes are planned to test drilling

gaps in this area that is along the eastward strike extension of the faults that control the main portion of

the Hurricane deposit.

Finally, review of historical drill hole data reveals that the northern faults at Hurricane – intersected in

holes drilled from the north to intersect the deposit at depth (e.g. LE19-15) - remain largely untested at

the unconformity, presenting a compelling target which will be tested this winter.

Figure 2 – Location of planned winter 2025 drill holes with respect to the Hurricane deposit resource

footprint (blue) and the ANT seismic low velocity zone in which the deposit occurs.

Regional Targets on the Larocque Trend

With addition of a second drill rig, drilling of greenfield targets are expected to proceed from west to east

across the Larocque Trend, as drill trails are prepared. The Larocque Trend is an important regional

structure that hosts the world-class Hurricane deposit and other notable high-grade occurrences including

those on Cameco/Orano’s Dawn Lake joint venture (Figure 3).

Figure 3 – Location of the Larocque Trend which hosts the high-grade Hurricane deposit and high-

grade uranium occurrences on adjacent projects. IsoEnergy’s winter 2025 drilling will be focussed on

this trend east of the Hurricane deposit on the Larocque East project.

* See Qualified Person Statement below.

Three of the target areas (D, E, and F) defined in 2024 that will be prioritized are characterized by

anomalous Up geochemistry, indicative clay species alteration mineralogy, and prospective structure

projected from nearby holes within the Larocque Trend and within seismic low velocity zones defined by

2024 ANT surveys and resistivity lows outlined by past DC -resistivity surveys . A joint inversion of

electromagnetic and DC resistivity data to develop improved resistivity mapping of alteration is in progress

and will be used in refining drill targets. Planned drill holes will be focussed initially in areas D, E and F and

plans will evolve depending on results as the program proceeds. Unconformity target depth shallows to

the east and is at 175 m vertical depth in hole LE24-180 at Area E versus a 325 m at the Hurricane deposit.

Area D, corresponding to adjacent portions of areas D, I and J as defined by 2024 ANT surveys ( see

November 6, 2024, press release). The target area coincides with ANT low velocity and low DC-resistivity

zones on the conductor corridor zone. Drill hole LE22-116 intersected 369 parts per million uranium partial

(“ppm Up”) in basal sandstone from 281.5 to 282.0 m and 2,750 ppm U p from 282.0 to 282.5 m in the

basement (see July 15, 2022, press release). Similarly, drill hole LE24-177, completed during the summer

of 2024, intersected up to 42.8 ppm Up in basal sandstone. This hole also encountered strong alteration

features, including hydrothermal hematite and clay, along with significant sandstone structural

characteristics.

Area E corresponds to an ANT velocity low roughly coincident with the hinge of an east -trending,

moderately west-plunging fold at the east end of the property , where IsoEnergy’s 2024 summer drilling

following up on historic hole KER-17 intersected significant structures in all drill holes. Drill hole LE24-192

recorded up to 334 ppm Up over 0.5 m in sandstone and up to 1,110 ppm Up in the basement. Drill hole

LE24-180 intersected up to 462 ppm Up in sandstone, while LE24-190 encountered strong clay alteration

and structural features from 209 m to the unconformity at 268.6 m. Additionally, this hole recorded >1

ppm Up below 180 m in sandstone, with a maximum of 7.0 ppm Up from 265.1 to 265.6 m.

Area F, located in the northeast, is centered on the conductor corridor and aligns with roughly coincident

ANT velocity low and resistivity anomalies. 2025 drilling i n areas E and F will also help correlations

between fertile trends on the Larocque East project and conductors on the Turnor Lake project to the east

which is now part of a joint venture between IsoEnergy and Purepoint created in 2024 and on which

Purepoint, as the exploration operator, is proposing exploration plans for 2025.

Figure 4 – Location of winter 2025 target areas along the Larocque Trend east of the Hurricane deposit.

Developing Drill Targets on Additional Highly Ranked Projects

Ground gravity surveys are planned on the East Rim and Evergreen projects (Figure 1) that cover multiple

conductive and structural corridors on the southeast basin margin. Stepwise moving loop electromagnetic

surveys are planned for the Hawk project (Figure 1) to further refine the interpretation of conductor plates

(proxies for graphitic faults and rock units) that are used along with low seismic velocity zones mapped by

ANT surveys (proxies for rock alteration) and existing drill hole geology and geochemistry information to

identify drill targets on the Hawk project. The goal of these geophysical surveys is to advance targ ets on

these highly prospective early -stage projects to the drill -ready stage. Contractor selection is in progress

and work permits are expected to be received in February 2025.

Update on Plan of Arrangement with Anfield

IsoEnergy also wishes to provide an update in connection with the previously announced plan of

arrangement with Anfield Energy Inc. (“Anfield”) under the Business Corporations Act (British Columbia)

(the “Arrangement”). While the outside date under the arrangement agreement has passed, IsoEnergy is

continuing to consider the Arrangement and potential options and alternatives. IsoEnergy will update the

market as soon as further information becomes available.

Qualified Person Statement

The scientific and technical information contained in this news release was reviewed and approved by Dr.

Dan Brisbin, P.Geo., IsoEnergy’s Vice President, Exploration, who is a “Qualified Person” (as defined in NI

43-101 – Standards of Disclosure for Mineral Projects). All 'HK' and 'LE' series drill holes were completed

by IsoEnergy, and geochemical analyses were completed for the Company by SRC Geoanalytical

Laboratories (“SRC”) in Saskatoon, Saskatchewan, which is independent of the Company . All other dri ll

holes were completed by previous operators and geochemical assay data has been compiled from

historical assessment reports or provided by the previous operator(s).

For additional information regarding the Company’s Larocque East Project, including the current mineral

resource estimate for IsoEnergy’s Hurricane Deposit [and the quality assurance and quality control

(“QA/QC”) procedures applied to the exploration work described in this news release, please see the

Technical Report titled “Technical Report on the Larocque East Project, Northern Saskatchewan, Canada”

dated August 4, 2022, on the Company’s profile at www.sedarplus.ca.

Quality Assurance and Quality Control (QA/QC)

Quality Assurance in uranium exploration benefits from the use of down -hole gamma probes and hand-

held scintillometers/spectrometers, as discrepancies between radioactivity levels and geochemistry can

be readily identified.

IsoEnergy implemented its QA/QC program in 2019. CRMs are used to determine laboratory accuracy in

the analysis of mineralized and unmineralized samples. Duplicate samples are used to determine

analytical precision and repeatability. Blank samples are used to test for cross contamination during

preparation and analysis stages. For each mineralized drill hole at least one certified reference material

(CRM) blank, one CRM standard, and one duplicate sample (MDUP) is inserted in the MINZ sample series.

One of two CRM standards is used: OREAS 124 (O124) if maximum grade is <1% eU 3O8 or BL-5 (BL5) if

maximum grade is >1% eU3O8.

For unmineralized samples such as composite and spot samples, field insertions are made at the rate of

1% for blanks, 2% for duplicates and 1% CRMs. The following protocols are followed:

• Sample IDs ending in 00 will be certified blanks (BLA1).

•Sample IDs ending in 25 and 75 will be duplicates (DUPL) of the preceding sample.

• Sample IDs ending in 50 will be CRM OREAS 120 (O120).

In addition to IsoEnergy’s QA/QC program, SRC conducted an independent QA/QC program, and its

laboratory repeats (REPT), non -radioactive laboratory standards (LSTD), and radioactive lab standards

(BL2A, BL4A, BL5) were monitored and tracked by IsoEnergy staff.

No QA/QC samples are inserted for reflectance samples as analyses are semi-quantitative only.

Assaying and Analytical Procedures

Composite and spot samples were shipped to SRC Geoanalytical Laboratories in Saskatoon for sample

preparation and analysis. SRC is an independent laboratory with ISO/IEC 17025: 2005 accreditation for

the relevant procedures.

The samples were then dried, crushed, and pulverized as part of the ICPMS Exploration Package (codes

ICPMS1 and ICPMS2) plus boron (code Boron). Samples were analyzed for uranium content, a variety of

pathfinder elements, rare earth elements, and whole roc k constituents with the ICPMS Exploration

Package (plus boron). The Exploration Package consists of three analyses using a combination of

inductively coupled plasma - mass spectrometry, inductively coupled plasma -optical emission

spectrometry (“ICP- OES”), and partial or total acid digestion of one aliquot of representative sample pulp

per analysis. Total digestion is performed via a combination of hydrofluoric, nitric, and perchloric acids

while partial digestion is completed via nitric and hydrochloric ac ids. In-house quality control performed

by SRC consists of multiple instrumental and analytic checks using an in -house standard ASR316.

Instrumental check protocols consist of two calibration blanks and two calibration standards. Analytical

protocols require one blank, two QA/QC standards, and one replicate sample analysis.

Samples with radioactivity over 350 CPS measured by Radiation Solutions RS - 125 were also shipped to

SRC. Sample preparation procedures are the same as for the ICPMS Exploration Package, samples were

analyzed by ICP-OES only (Code ICP1) and for U 3O8 using hydrochloric and nitric acid digestion followed

by ICP-OES finish, capable of detecting U3O8 weight percent as low as 0.001%.

Selective samples to be analyzed for gold, and in some instances, platinum and palladium, by fire assay

using aqua regia digestion with ICP -OES finish. Analytical protocols utilized replicate sample analysis;

however, no in-house standards were used for these small batches. Boron analysis has a lower detection

limit of 2 ppm and is completed via ICP -OES after the aliquot is fused in a mixture of s odium superoxide

(NaO2) and NaCO3. SRC in-house quality control for boron analysis consists of a blank, QC standards and

one replicate with each batch of samples.

Borehole Radiometric Probing Method

All successfully completed 2024 drillholes were radiometrically logged using calibrated downhole Mount

Sopris 2PGA-1000 probe which collects reading every 10 cm along the length of the drillhole. The 2PGA -

probe was sourced from Alpha Nuclear and was calibrated for the summer 2024 program by IsoEnergy

geologists at Saskatchewan Research Council facility in Saskatoon in May 2024. The total count gamma

readings using the 2PGA -1000 probe may not be directly or uniformly related to uranium grades of the

interval measured and are only a preliminary indication of the presence of radioactive minerals.

Sample Collection Methods

All drill core was systematically logged to record its geological and geotechnical attributes by IsoEnergy

geologists and geological technicians. All drill core is systematically photographed and scanned for

radioactivity with a handheld Radiation Solutions RS -125 spectrome ter. IsoEnergy geologists mark ed

sample intervals and sample types to be collected based on geological features in the core and on

radioactivity measured with the RS-125 in counts per second (CPS). Geologists and geological technicians

complete the on-site collection of several types of samples from drill cores.

Composite geochemistry samples consist of roughly one-centimetre-long chips of core collected every 1.5

m to geochemically characterize unmineralized sections of sandstone and basement. Composite sample

lengths are between five and ten m (typically 3 to 7 chips per sample). A minor revision to the sampling

protocols introduced in 2024 is that rather than maintaining five metre sample lengths from 50 m above

the unconformity to the unconformity, f or five metres above and two metres below the unconformity

composite sample intervals are now only 0.5 m long and the samples are composed of several chips of

core in each interval. This is to provide better resolution of anomalous geochemistry along the

unconformity, especially in greenfield exploration drill holes.

Split-core“spot” (i.e., representative) samples were collected through zones of significant but

unmineralized alteration and/or structure. Spot sample length varies depending on the width of the

feature of interest but are generally 0.5 m in length.

Split-core mineralization (“MINZ”) samples are collected through zones of elevated radioactivity

exceeding 350 CPS measured via RS -125 handheld spectrometer. MINZ samples are generally 0.5 m in

length. One half of the core was collected for geochemical analysis while the remaining half is returned to

the core box for storage on site. Intervals covered by MINZ samples are contiguous with and do not

overlap intervals covered by composite samples.

Systematic short-wave infrared (“SWIR”) reflectance (“REFL”) samples were collected from approximately

the middle of each composite sample for analysis of clays, micas, and a suite of other generally hydrous

minerals which have exploration significance. Spot reflectance samples were collected where warranted

(i.e., fracture coatings). Reflectance samples are not collected through mineralized zone.

For lithogeochemistry samples, sample tags with the sample number were placed in the sample bags

before they are sealed and packed in plastic pails or steel drums for shipment to the Saskatchewan

Research Council (“SRC”) Geoanalytical Laboratories in Saskatoon, Saskatchewan. A second set of sample

tags with the depth interval and sample number were stapled in the core box at the end of each sample

interval. A third set of sample tag with the drill hole number, sample depth interval, and sample number

were retained in the sample book for archiving. SWIR reflectance samples are tagged in a similar fashion

as lithogeochemistry samples.

Geologists enter ed all geological, geotechnical and sample interval data into IsoEnergy’s drill hole

database during core logging.

Sample Shipment and Security

Drill core was delivered from the drill to IsoEnergy’s core handling facilities at the Larocque Lake camp

thereafter. Individual core samples were collected at the core facilities by manual splitting. They were

tagged, bagged, and then packaged in five-gallon plastic buckets or steel IP-2 drums for shipment to SRC

labs in Saskatoon. Shipment to the laboratory was completed by IsoEnergy’s expeditor, Little Rock

Enterprises of La Ronge, Saskatchewan and by Points North Freight Forwarding Inc. of Points North

Landing, Saskatchewan.

About IsoEnergy Ltd.

IsoEnergy Ltd. (TSX: ISO) (OTCQX: ISENF) is a leading, globally diversified uranium company with

substantial current and historical mineral resources in top uranium mining jurisdictions of Canada, the

U.S., Australia, and Argentina at varying stages of development, providing near, medium, and long-term

leverage to rising uranium prices. IsoEnergy is currently advancing its Larocque East Project in Canada’s

Athabasca Basin, which is home to the Hurricane deposit, boasting the world’s highest grade Indicated

uranium Mineral Resource.