Mr. Philip Williams reports

ISOENERGY INITIATES BULK SAMPLE PROGRAM AT THE TONY M URANIUM MINE IN UTAH, A KEY STEP TOWARD A POTENTIAL RESTART DECISION

IsoEnergy Ltd. has begun a bulk sample program at its 100-per-cent-owned Tony M uranium mine in Utah. The bulk sample is designed to collect key technical, operational and economic data required as one of the steps to support a potential production restart decision at one of the few fully permitted, past-producing conventional uranium mines in the United States.

The bulk sample program will involve the extraction of up to 2,000 tons of mineralized material over a 12- to 14-week period (which commenced late December, 2025) and will be executed using contract mining services provided by GenX Mining Contractors LLC of Spring Creek, Nev. Mineralized material recovered during the program will be transported to the White Mesa mill in Utah, owned by Energy Fuels Inc., for processing.

With U.S. utilities increasingly focused on securing domestic uranium supply and limited near-term production capacity available, IsoEnergy believes Tony M represents a rare opportunity to advance a permitted, infrastructure-ready uranium mine toward potential restart without the need for costly and timely mill construction/refurbishment or major permitting initiatives. The bulk sample is a critical step in defining the scope and economics of a future production plan at Tony M. This work aligns with U.S. federal initiatives focused on rebuilding domestic nuclear fuel supply chains and enhancing energy security through increased domestic uranium production.

Upon completion of the bulk sample, IsoEnergy expects to evaluate the results alongside continuing optimization studies to determine next steps, which may include advancing detailed mine planning, finalizing restart sequencing and assessing the timing of a potential production decision.

Highlights:

• Bulk sample designed as a decision gate toward potential restart:
  • Low-risk, limited-scope program structured to generate real-world mining, processing and cost data required to evaluate a potential restart decision;
  • Results expected to inform mine planning, sequencing and commercial production assumptions;
• Derisking mining methods and cost structure under operating conditions:
  • Establishes actual contract mining costs and validates assumptions used in economic models;
  • Refines mineral material control strategies to minimize dilution and maximize delivered grade, including testing dilution control techniques in a production-style environment;
• Processing pathway established through existing toll milling agreement:
  • Mineralized material to be processed at the White Mesa mill, eliminating the need for new mill construction and materially reducing capital intensity and execution risk;
  • Enables IsoEnergy to focus capital and effort on mine restart and optimization rather than downstream infrastructure;
• Production-ready underground systems and execution tested:
  • Trial ventilation, ground control and underground operating procedures ahead of full-scale mining.

Philip Williams, chief executive officer and director of IsoEnergy, commented: "The bulk sample at Tony M is a major milestone in advancing one of the few restart-ready uranium mines in the United States. This program is designed to generate the real-world data we need to evaluate a potential full-scale production restart under current market conditions. With permitting, infrastructure and toll milling already in place, Tony M has the potential to be among the next conventional uranium mines in the U.S. to return to production as demand for secure domestic supply continues to grow."

Progress on Tony M mine work programs

During 2025, IsoEnergy advanced a series of initiatives designed to strengthen the operating and economic profile of Tony M, including, reducing the uranium production royalty on the Utah Trust Lands Administration lease from 8 per cent to 3 per cent, high-pressure slurry ablation testing, which has demonstrated the potential to recover more than 90 per cent of the uranium into roughly 25 per cent of the original mass, and mineralized material-sorting testwork completed in October, which achieved over 90 per cent recovery into roughly 50 per cent of the original mass for material amenable to sorting. In parallel, an enhanced evaporation study has shown that Landshark evaporators eliminate the need for evaporation pond expansion and reduce both permitting timelines and capital requirements. Together, these work programs support the company's strategy of systematically derisking Tony M and improving the economic framework for a future production decision.

About Tony M mine

The Tony M mine is located in eastern Garfield county, southeastern Utah, approximately 66 air miles (107 kilometres) west-northwest of the town of Blanding and 215 miles (347 kilometers) south-southeast of Salt Lake City. The project is the site of the Tony M underground uranium mine that was developed by Plateau Resources, a subsidiary of Consumer Power Company, in the mid-1970s.

Uranium and vanadium mineralization at the Tony M mine is hosted in sandstone units of the Salt Wash member of the Jurassic age Morrison formation, one of the principal hosts for uranium deposits in the Colorado plateau region of Utah and Colorado.

Tony M has the following current mineral resource estimate.

Qualified person statement

The scientific and technical information contained in this news release was reviewed and approved by Dean T. Wilton, PG, CPG, MAIG, a consultant of IsoEnergy, who is a qualified person (as defined in National Instrument 43-101 (Standards of Disclosure for Mineral Projects).

About IsoEnergy Ltd.

IsoEnergy is a leading, globally diversified uranium company with substantial current and historical mineral resources in top uranium mining jurisdictions of Canada, the United States and Australia 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. IsoEnergy also holds a portfolio of permitted past-producing, conventional uranium and vanadium mines in Utah with a toll milling arrangement in place with Energy Fuels. These mines are currently on standby, ready for rapid restart as market conditions permit, positioning IsoEnergy as a near-term uranium producer.

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