Overview
Idaho Strategic’s Lemhi Pass project covers approximately 11,425 acres and is comprised of a mixture of unpatented lode mining claims, a State of Idaho mineral lease, and a mineral claim lease with a private company. Lemhi Pass is strategically located approximately 35 miles from the company’s Diamond Creek and Mineral Hill rare earth elements holdings and 124 miles from Idaho National Laboratory’s (INL) Advanced Test Reactor (ATR). The United States is tied for third in the world in identified thorium resources and the Lemhi Pass district represents the largest concentration of thorium resources in the United States, per the USGS.
Mineralization
The Lemhi district represents a major thorium resource where mineralization occurs in veins. The veins consist of mostly quartz and occupy primarily northwest-trending steeply-dipping shear zones in quartzite and finer grain metamorphic rocks of the Precambrian Belt Supergroup. In many cases the veins occur as small en echelon structures within a major through-going shear zone up to 6000 feet in length. Veins attain a maximum known width of 40 feet. Lengths of veins are unknown, but some have been traced discontinuously for nearly two miles.
Clean Core Thorium MoU
In May 2025, Idaho Strategic signed a Memorandum of Understanding (MOU) with Clean Core Thorium Energy, Inc. (CCTE) to explore the feasibility of sourcing thorium from Idaho Strategic's Lemhi Pass project and processing it for use in CCTE’s ANEEL fuel, a patented thorium and high-assay low-enriched uranium (HALEU) blend designed for pressurized heavy water reactors (PHWRs). The partnership aims to establish a "Made in America" supply chain for thorium-based nuclear fuel, leveraging Idaho Strategic’s dominant control over the Lemhi Pass District, considered by the United States Geological Survey to be largest domestic source of thorium resources, and CCTE’s innovative fuel technology that enhances safety, reduces waste, and improves efficiency. Both companies see nuclear power as a key to carbon-free energy, with the MOU enabling them to combine Idaho Strategic’s in-situ thorium mineralization with CCTE’s expertise to advance the U.S.' domestic nuclear industry.
Staatz, 1979 Report
The United States is tied for third in the world identified thorium resources. The Lemhi Pass district represents the largest concentration of thorium resources in the United States. The 10 largest veins in Lemhi Pass district represent 95 percent of the district’s identified thorium resources.
Largest Concentration of Thorium in the U.S., per the USGS
Geach, 1966: Size and Grade of Various Types of Thorium Deposits
The Table above is a copy of Figure 2 from Robert Geach's 1966 report titled, Thorium Deposits of the Lemhi Pass District, Beaverhead County, Montana.
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