Red Mountain Mining turns attention to Idaho’s ‘Silver Dollar’ antimony project

The past-producing site churned out ore with an average grade of 17.7% Sb during the WWII era

Rowan Dunne

Published

October 7, 2025

Red Mountain Mining Ltd (FRA: RM0) (ASX: RMX) has expanded its antimony mining footprint with the acquisition of a past-producing mine site in Idaho. The purchase has increased the junior’s land holding in the state by about 80 per cent.

Red Mountain is not the only Australian mining company to prioritize American antimony (Sb) prospecting as the commodity continues to pull attention from investors. Near its newly obtained Silver Dollar project and the smaller Yellow Pine operation in the state of Idaho, the prospector is joined by Trigg Minerals Ltd (OTCMKTS: TMGLF) (ASX: TMG).

Meanwhile, other ASX-listed companies are engaged with drill campaigns in Alaska, Nevada and California. Namely Nova Minerals Ltd (OTCMKTS: NVAAF) (FRA: QM3) (ASX: NVA), EV Resources Ltd (FRA: R1EA) (ASX: EVR) and Locksley Resources Ltd (OTCMKTS: LKYRF) (ASX: LKY).

Red Mountain’s newly obtained Idaho mine site produced antimony during the 1940s as the Allied forces needed vast quantities for the war effort. Silver Dollar yielded ore with an average grade of 17.7 per cent Sb, as specified by the company.

“RMX’s Silver Dollar claims encompass four known alluvial gold and two antimony mineral occurrences,” Red Mountain explained in an ASX announcement, “including the Silver Dollar Mine, which features a 10-metre deep shaft sunk into fractured granodiorite in 1944, targeting a massive stibnite vein up to 1 metre thick.”

Red Mountain will be completing a mapping and sampling campaign at the project to start. The company aims to identify suitable drill targets. At Yellow Pine to the southeast, acquired late last month, the junior is currently completing a similar exploratory program.

“Antimony prices have surged to US$60,000 per tonne in recent months with the backdrop of the Chinese Government banning its export to the United States,” Red Mountain said on social media recently.

“In 2024, the USA produced zero antimony metal from mining operations” the company highlighted.

“Red Mountain’s US based team is now rapidly deploying to advance exploration.”

In addition to antimony, Silver Dollar is estimated to hold significant gold, silver and uranium potential. More broadly, Idaho is renowned for its abundant gold mineralization. One precious metal and antimony mining company active in the state, NevGold Corp (CVE: NAU) (OTCMKTS: NAUFF) (FRA: 5E50), recently boosted its resources in the jurisdiction with an updated MRE.

Red Mountain has also been pursuing stibnite veins and Sb mineralization in Utah and at home in New South Wales.

Stockhead put Red Mountain on its list of the top 50 best performing ASX stocks on Oct. 3.