Red Mountain Mining has acquired the Thompson Falls Antimony Project on the Montana-Idaho border, adjacent to the only operating antimony smelter in the US. Early assays reveal exceptional grades, positioning the company to capitalise on critical mineral supply chain demands.
- Acquisition of Thompson Falls Project near US Antimony Corporation’s smelter
- Initial assays show up to 36.5% antimony and 0.65g/t gold
- Project located within historic Coeur d’Alene polymetallic district
- Strategic alignment with US and Australian critical minerals policies
- Further exploration and sampling planned to define drill targets
Strategic Acquisition in a Critical Minerals Hotspot
Red Mountain Mining Ltd (ASX – RMX) has made a significant move by acquiring the Thompson Falls Antimony Project, straddling the Montana-Idaho border. This project is uniquely positioned adjacent to the United States Antimony Corporation’s operations, which include the nation’s only antimony smelter. Given antimony’s designation as a critical mineral by both the US and Australian governments, this acquisition places Red Mountain at the heart of a strategically vital supply chain.
The proximity to US Antimony Corporation’s Thompson Falls Smelter and the Stibnite Hill Mine; one of the largest known stibnite vein deposits in the US; offers Red Mountain a rare opportunity to leverage existing infrastructure and market demand. The US government’s recent $12 billion strategic minerals stockpile initiative underscores the urgency of securing domestic sources of critical minerals like antimony and silver.
Promising Early Exploration Results
Initial reconnaissance and sampling at Thompson Falls have yielded impressive assay results, with antimony grades reaching as high as 36.5% and gold up to 0.65 grams per tonne. These results come from grab samples taken near three historical underground mines and a pit within the project area. While these samples are not yet representative for resource estimation, they strongly indicate the presence of high-grade mineralisation similar to that found at the nearby Stibnite Hill Mine.
The project also lies at the eastern edge of Idaho’s renowned Coeur d’Alene mineral district, historically one of the richest silver-producing regions in the US. This polymetallic district has produced substantial quantities of silver, lead, zinc, gold, copper, and antimony over more than a century, suggesting the Thompson Falls Project could host a diverse suite of valuable metals.
Exploration Plans and Broader Portfolio Context
Red Mountain is actively advancing exploration, with further assay results expected this quarter. The company plans additional reconnaissance to identify any undocumented historical workings and mineralised exposures, alongside detailed sampling of the underground mines already located. These efforts aim to refine drill targets and better understand the mineralisation’s extent and quality.
This acquisition complements Red Mountain’s existing US and Australian critical minerals portfolio, which includes projects in Utah, Idaho, and New South Wales. The company is accelerating development at its Armidale Antimony-Gold Project in NSW, where high-grade antimony samples have also been reported. Together, these assets position Red Mountain to benefit from growing government support and market demand for secure, Western-sourced critical minerals.
Navigating Supply Chain Security and Market Dynamics
Antimony’s critical status stems from its essential role in flame retardants, batteries, and other industrial applications, coupled with supply risks due to geopolitical factors, including China’s export restrictions. The US government’s strategic stockpile initiative and the restart of mining operations at Stibnite Hill by US Antimony Corporation highlight the urgency of developing domestic sources.
Red Mountain’s Thompson Falls Project, secured for a modest $158,000, offers a foothold in this high-demand sector. However, the path from exploration to production remains to be charted, with further drilling and resource definition required. The company’s ability to advance these projects amid evolving market and regulatory landscapes will be critical to unlocking value.
Bottom Line?
Red Mountain’s Thompson Falls acquisition marks a pivotal step in securing critical mineral supply chains, but the journey from promising assays to production will require careful navigation.
Questions in the middle?
- What will forthcoming assay results reveal about the project’s resource potential?
- How quickly can Red Mountain advance drilling and define a viable resource at Thompson Falls?
- What impact will US government policies have on project development and financing?