American Rare Earths Ltd has lifted the mineral resource estimate (MRE) at its Halleck Creek Rare Earth Project in Wyoming, USA, by 12.2% to 2.63 billion tonnes at 3,922 ppm total rare earth oxides (TREO), highlighting the transformational scalability of the project, which remains open at depth and along strike.
The major resource update further establishes Halleck Creek as one of the largest rare earth deposits in North America and underscores ARR’s progress in unlocking its potential as a strategic US asset.
“This resource update demonstrates the continued growth, scale and strategic importance of Halleck Creek as a cornerstone project for the US rare earth supply chain,” American Rare Earths CEO Chris Gibbs said.
“With the deposit still open at depth, and along strike, the upside potential is truly remarkable.
“With the Halleck Creek mineral resource estimate covering approximately 16% of the greater Halleck Creek project surface area, we believe opportunities exist to expand mineral resource estimates with additional exploration.”
Halleck Creek’s favourable geology and near-surface mineralisation support the potential for a low-cost open-pit mining operation, while ongoing metallurgical test work continues to demonstrate the potential for efficient processing of rare earths.
The project’s location on Wyoming State land provides a streamlined permitting process, accelerating ARR’s ability to unlock the project’s full value.
Mineral resource upgrade
The Red Mountain Area within Halleck Creek saw a 29.7% growth in resources to 1.24 billion tonnes, with an 8.3% uplift in grade to 3,252 ppm TREO.
Cowboy State Mine (CSM) remains central to ARR’s development strategy and will represent the first phase of project development within Red Mountain.
The CSM resource continues to deliver robust growth of 29.4% to 543 million tonnes and a 2.7% increase in TREO grade to 3,438 ppm.
Importantly, these results reinforce ARR’s ability to support the US Government’s efforts to secure domestic critical mineral independence, reducing reliance on imports and supporting economic growth and national security objectives.
What’s ahead?
ARR is integrating the updated resource and high-grade data into the scoping study, originally released in March 2024. The updated study is nearing completion and will be released next month.
The updated resource model and mine plans are expected to have a positive impact on Halleck Creek’s project economics, further enhancing its strategic importance.
The updated resource estimates will also be incorporated into an ongoing pre-feasibility study (PFS), which remains on track for completion later this year. The PFS will provide a more detailed evaluation of Halleck Creek’s technical and economic potential, supporting ARR’s phased approach to development and commercial production.
Gibbs said, “The expanded resources will strengthen the project's economics as we finalise the updated scoping study, which is set for release shortly, and continue integrating this data into the pre-feasibility study, scheduled for completion later this year.
“Halleck Creek is positioned to become one of the most significant rare earth assets in North America, supporting US critical mineral independence and economic growth.”
In parallel, ongoing metallurgical test work continues to deliver promising results, highlighting the potential for cost-efficient processing at Halleck Creek.
As outlined in the 2024 scoping study, around 90% of the gangue (waste) material can be removed during gravity and magnetic separation, significantly increasing REE grades through physical separation methods prior to leaching — significantly reducing operational costs.
Optimising these processing techniques is ongoing and ARR will announce further results as the next round of metallurgical testing is completed later this quarter.