American Rare Earths Ltd (ASX:ARR, OTCQB:ARRNF), through its subsidiary Wyoming Rare (USA) Inc., has begun construction of a test mine at the Cowboy State Mine, part of the Halleck Creek deposit in Wyoming. The program, operating under a State of Wyoming License to Explore by Dozing, will extract about 3,200 tonnes of ore to provide feedstock for a planned demonstration plant. Bulk sampling will also support ongoing mineral processing optimisation.
The company has already completed the first of two scheduled blasts, fracturing weathered material to a depth of 3.6 metres, which is now being excavated and stockpiled. Once removed, underlying non-weathered ore will be blasted, crushed to five centimetres, and stockpiled for further work.
Excavation of the blasted, weathered material at the CSM Test Mine.
Ore use and processing optimisation
The crushed ore extracted from the test pit will be used across three primary activities: metallurgical testing and process optimisation, building a stockpile for the demonstration plant, and producing end-product samples for potential offtake partners.
License to Explore Extent and Cowboy State Mine Test Pit Map.
Weathered material removed during excavation will be returned as backfill upon project completion. The test mining activities will also generate valuable operational data, including drill penetration rates, blast fragmentation quality, and other information relevant to mine design. These insights will feed into refining future mine planning and cost estimates.
Strategic importance of test mining
The start of test mining marks a critical milestone in American Rare Earths’ development pathway.
Demonstration plants require substantial ore volumes to validate processing flowsheets, generate samples for industry stakeholders, and underpin future technical studies.
This program aims to de-risk future development by proving processing performance at scale, refine engineering and cost models, and support commercial discussions with potential offtake partners. Importantly, the project also serves to strengthen investor and stakeholder confidence in the viability of the Halleck Creek development.
About American Rare Earths
American Rare Earths is advancing the Halleck Creek Project in Wyoming through its subsidiary Wyoming Rare (USA) Inc. The deposit is considered one of the largest rare earth resources in the United States, with the Cowboy State Mine offering potential for cost-efficient open-pit mining.
Located on Wyoming state land, the project benefits from streamlined permitting and a favourable regulatory environment. With plans to establish onsite processing and separation facilities, Halleck Creek is strategically positioned to reduce US reliance on imports, particularly from China, while supplying materials essential for defence, technology, and economic security.
The company is committed to environmentally responsible mining practices and is engaged in US government-supported R&D initiatives focused on innovative rare earth extraction and processing methods