IsoEnergy Advances Flatiron Drilling & Completes Tony M Bulk Sample Mining as US Strategy Takes Shape

• IsoEnergy (NYSE American: ISOU; TSX: ISO) has mobilised drill equipment to its Flatiron Project in Utah's Henry Mountain uranium district and will complete seven surface rotary holes with core tails, totalling 11,000 feet, building on three holes drilled in late 2025.
• Flatiron spans 8,800 acres - one of the largest contiguous land positions in the Henry Mountain District - and is positioned along the structural projection of uranium mineralisation from IsoEnergy's Tony M deposit and Energy Fuels' Bullfrog deposit.
• The drilling targets the lowest sandstone unit of the Salt Wash Member of the Morrison Formation, the primary uranium host across the district, following up on wide-spaced historical exploration by Plateau Resources in the early 1980s that was halted by uranium price weakness.
• IsoEnergy has completed the mining phase of its Tony M bulk sample, recovering approximately 2,100 tons of mineralised material with no injuries or lost-time incidents; the material is stored on-site and will be delivered to Energy Fuels' White Mesa Mill for processing, potentially after a larger-scale ore-sorting or upgrading step.
• Data from the bulk sample - covering mining rates, sequencing, equipment sizing, costs, dilution, grade control, and operational procedures - will feed directly into an NI 43-101 Preliminary Economic Assessment (PEA) that the company is targeting for completion before the end of 2026.

Systematic Drilling Resumes at Flatiron

IsoEnergy (NYSE American: ISOU; TSX: ISO) has completed drill mobilisation to the Flatiron Project in Utah's Henry Mountain uranium district and is advancing a seven-hole surface rotary programme with core tails totalling 11,000 feet. The 2026 campaign is designed as a systematic follow-up to three holes completed at the project in late 2025 and to historical district-scale exploration conducted by Plateau Resources in the early 1980s.

Flatiron sits approximately seven miles northwest of IsoEnergy's past-producing Tony M uranium mine and is strategically positioned along the projection of uranium mineralisation trends shared with Tony M and Energy Fuels Inc.'s (NYSE American: UUUU; TSX: EFR) Bullfrog deposit. IsoEnergy staked the project's 370 lode claims in 2024 before adding two Utah state leases, bringing the total land position to 8,800 acres - one of the largest contiguous holdings in the Henry Mountain District, where cumulative uranium production has reached approximately 1.4 million pounds of uranium oxide (U3O8) to date, per the Utah Geological Survey Open-File Report 735 (2021).

The target horizon is the lowest sandstone unit of the Salt Wash Member of the Morrison Formation, the primary uranium host unit across the Henry Mountain district. The formation contains sufficient reductant material and hydrogeologic conditions to support commercially viable uranium grades; low-grade vanadium mineralisation is also anticipated in the host unit. Plateau Resources - the original developer of Tony M and Bullfrog - previously drilled on centres of more than one mile to identify concealed uranium mineralisation across this formation, with two of the highest-priority historical intercepts falling within the current Flatiron claim boundary. Declining uranium prices in the 1980s forced the closure of regional operations before those targets could be advanced; the 2026 IsoEnergy programme represents the first systematic follow-up on that historical work. Results from the three 2025 holes have informed interpretation of the sandstone channel geometry and been used to plan collar locations for the current campaign.

Tony M Bulk Sample: Mining Phase Completed

IsoEnergy has confirmed completion of the mining component of its Tony M bulk sample, which was originally announced on 7 January 2026. Working with contractor Gen X Mining Contractors, the company extracted approximately 2,100 tons of mineralised material from Tony M without any injuries or lost-time incidents. The material is currently stored safely on-site at Tony M.

The bulk sample programme served as an operational test bed, allowing the company to evaluate health and safety protocols, ground control, ventilation, drilling and blasting procedures, and grade control systems. Multiple types and sizes of mining equipment were trialled, generating a dataset on mining rates, sequencing, equipment sizing, costs, dilution, and operational procedures that the company expects to incorporate into the forthcoming NI 43-101 PEA.

The company is evaluating an ore-sorting or upgrading step using the bulk sample material prior to delivery to Energy Fuels' White Mesa Mill. Small-scale testing conducted during 2025 produced encouraging results from two technologies: high-pressure slurry ablation demonstrated the potential to recover more than 90% of uranium into roughly 25% of the original mass, while mineralised material sorting achieved more than 90% recovery into roughly 50% of the original mass for amenable material. If these results hold at larger scale, the company expects them to translate into materially lower hauling and processing costs during potential future mine operations.

Philip Williams, Chief Executive Officer and Director of IsoEnergy, commented:

"Restarting drilling at Flatiron and the completion of the Tony M Bulk Sample represent two important components of IsoEnergy's U.S. strategy. Our exploration program is focused on systematically building on decades of historical work to unlock the potential of the Henry Mountain District, while the results from the bulk sample simultaneously aid in de-risking Tony M for production. The data we are generating today will directly shape the economics of our PEA and our path to becoming a uranium producer and credit our team with having achieved all of this with zero lost-time incidents."

Next Steps and Upcoming Milestones

The seven-hole Flatiron drill programme is the immediate near-term catalyst, with mobilisation complete and drilling expected to begin shortly. Results from those holes will refine the company's understanding of the Salt Wash Member sandstone channel geometry and guide further exploration decisions in the Henry Mountain District.

At Tony M, the company is investigating the feasibility of a larger-scale ore-sorting or upgrading programme using the 2,100-ton bulk sample material before it is transported to Energy Fuels' White Mesa Mill for toll processing. The outcome of that investigation will determine the processing pathway for the material.

The primary corporate milestone is the NI 43-101 PEA for Tony M, targeting completion before the end of 2026. The company is currently in the final stage of consultant selection. The PEA will detail the scope and economics of potential production and identify the uranium price required to incentivise operations to begin, drawing directly on the operational and cost data generated by the bulk sample programme.

About IsoEnergy Ltd.

IsoEnergy Ltd. [NYSE American: ISOU; TSX: ISO] is a globally diversified uranium company with current and historical mineral resources across top uranium mining jurisdictions in Canada, the US, and Australia at varying stages of development. The company is advancing its Larocque East project in Canada's Athabasca Basin, home to the Hurricane deposit, which hosts the world's highest-grade indicated uranium mineral resource. IsoEnergy also holds a portfolio of permitted past-producing conventional uranium and vanadium mines in Utah, operating under a toll milling arrangement with Energy Fuels. Those mines are on standby and positioned for rapid restart as market conditions permit.

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