McEwen Files NI 43-101 Technical Reports: Grey Fox Prefeasibility Study in Ontario and Lookout Mountain and Windfall Mineral Resource Estimate in Nevada

McEwen Inc. has filed NI 43-101 technical reports covering the Grey Fox Project in Ontario, as well as the Lookout Mountain and Windfall deposits in Nevada. The Grey Fox Pre-Feasibility Study outlines a 15-year mine life that would extend the Fox Complex through 2041. Probable Mineral Reserves total 9.41 million tonnes grading 3.24 g/t Au, containing 980,300 gold ounces.

Base-case economics at $3,000/oz Au show a Life-of-Mine AISC of $2,212/oz, a post-tax NPV(5%) of $282 million, and an IRR of 24.8%. Initial capital expenditure for Grey Fox is estimated at $181 million, scheduled to be self-funded via treasury and operating cash flow.

Nevada reports confirm 629,800 oz Indicated and 262,000 oz Inferred Mineral Resources for Lookout Mountain and Windfall. Oxide mineralization at both Nevada deposits is identified as potentially amenable to heap-leach processing.

McEwen Inc. (MUX) has released a pre-feasibility study for its Grey Fox project, which provides economic validation for a 15-year life extension. The study adds approximately 980,000 ounces of probable reserves at a competitive all-in sustaining cost (AISC) of $2,212 per ounce. Additionally, resource updates in Nevada support the company’s strategic goal of expanding heap-leach operations at the Gold Bar complex.

Because the Grey Fox analysis is a pre-feasibility study rather than a bankable feasibility, final investment decisions, firm capital expenditure commitments, and permitting timelines are not yet locked. The stock has declined approximately 19% since the Q1 2026 earnings release on May 6, suggesting the market has already discounted the resource growth and is awaiting bankable economics and near-term production catalysts. While the news is positive and expected, it does not alter the near-term capital deployment schedule or resolve Argentine regulatory risks.

McEwen Inc. (MUX) is a diversified precious and base metals producer with assets in Canada, the United States, Mexico, and Argentina. The company’s portfolio includes the 100%-owned Fox Complex in Ontario, which produces gold via the Froome and Stock mines, and the 100%-owned Gold Bar Mine Complex in Nevada, an open-pit heap-leach operation with Lookout Mountain, Windfall, and Unity Ridge expansion targets.

In Manitoba, McEwen owns the Tartan Mine Project, a former producer undergoing restart evaluation. In Argentina, the company holds a 46.3% interest in Los Azules via McEwen Copper, a world-scale undeveloped copper project with a completed feasibility study, as well as a 49% interest in the San José Mine, which produces gold and silver. Additionally, McEwen owns the El Gallo Complex in Mexico, a Phase 1 heap-leach reprocessing project targeting mid-2027 production.