Red Mountain Mining has announced the acquisition of the Thompson Falls Antimony Project on the Montana-Idaho border in the US.
The project is located next to US Antimony Corporation’s (UAMY) facilities, home to the only antimony smelter currently operating in the country.
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The strategic acquisition aims to bolster Red Mountain’s portfolio in critical minerals, aligning with both US and Australian Government initiatives to secure mineral supply chains.
Initial assay results have shown high-grade findings including 36.5% antimony with 0.48 grams per tonne (g/t) gold, 21.0% antimony with 0.65g/t gold and 13.7% antimony with 0.14g/t gold.
The Thompson Falls project is located within the same geological formation as UAMY’s Stibnite Hill Mine, known for high-grade antimony deposits, which recently restarted operations.
Red Mountain has identified three historical underground mines and a pit within the project area, with samples indicating potential for silver-rich polymetallic vein mineralisation similar to that found in Idaho’s Coeur d’Alene district.
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By GlobalDataThe acquisition process was finalised using existing funds amounting to $158,000, coordinated by the Bureau of Land Management in both Idaho and Montana, amid a period that included a US federal government shutdown.
Red Mountain is set to continue exploration efforts including geological mapping and further sampling to evaluate additional historical workings and mineralised exposures.
The Thompson Falls project is positioned just 4.2km from UAMY’s smelter operations and is expected to benefit from the $12bn US Government initiative targeting critical minerals stockpiles.
Red Mountain plans further exploration activities to establish drill targets while awaiting additional assay results expected this quarter.
In September 2025, Red Mining announced the acquisition of 87 claims at the Utah Antimony Project in the US.
