American Rare Earths Ltd has fielded robust rare earth mineralisation from its latest channel sampling campaign at the Cowboy State Mine, part of the company’s flagship Halleck Creek Rare Earths Project in Wyoming, US.
Next major US rare earths project
“Halleck Creek is shaping up to be the next major rare earths project in the United States,” CEO Chris Gibbs said.
“With the high-value core four magnet rare earths including neodymium, praseodymium, dysprosium and terbium consistently present across the Cowboy State Mine, we are advancing one of the few US projects capable of supplying these critical materials at scale.
“What’s especially encouraging is the continued confirmation of these core four rare earths across the sampled area.
“In particular, terbium and dysprosium are vital for high-temperature magnet performance and remain in extremely limited supply outside of China.
“Based on our scoping study, they are expected to contribute over 25% of project revenues, despite representing a small percentage of overall tonnage.
“Importantly, we don’t need federal permitting reform to move forward. Being located on State lands in Wyoming gives us a clear and streamlined path to development.
“With China’s recent export bans on terbium and dysprosium, the national importance of Halleck Creek as a secure domestic source has never been clearer.
“As outlined in our updated scoping study, a staged development could see first production as early as 2029.
Multi-generational resource
“With its scale, simplicity and multi-generational resource potential, Halleck Creek has the attributes to become one of America’s most significant rare earths projects.”
A total of 106 channel samples were collected across the Red Mountain area by ARR’s US subsidiary, Wyoming Rare (USA) Inc, in collaboration with Geosyntec.
Assay results confirmed high concentrations of Total Rare Earth Oxides (TREO), with peak grades reaching 13,651 parts per million (ppm), or 1.37%.
The Red Mountain Pluton (RMP), which hosts the rare earth-bearing allanite mineralisation, returned TREO grades ranging from 711 ppm to 13,651 ppm, with an average of 3,661 ppm.
What’s more, 15 samples exceeded 4,500 ppm TREO, highlighting zones of enriched mineralisation.
Key rare earth components included magnet rare earth oxides (MREO), which averaged 1,023 ppm and accounted for approximately 28% of total TREO content.
Heavy rare earth oxides (HREO) made up around 13% of the TREO, averaging 464 ppm.
The results will be incorporated into an updated geological model and mineral resource estimate (MRE) for the Cowboy State Mine area.
These updates will inform mine design and support the ongoing pre-feasibility study (PFS), which remains on schedule for completion by late 2025.
The sampling campaign builds on previous resource modelling and is expected to refine pit designs and guide further development drilling.
Permits submitted
The company also confirmed that a permit application has been submitted to the Wyoming Department of Environmental Quality, enabling future exploration and development drilling to proceed post-PFS.
With the Cowboy State Mine located entirely on state lands, the project benefits from streamlined permitting pathways, which makes Halleck Creek a key strategic asset for the secure domestic supply of rare earths in the United States.