ASX-listed American Rare Earths outlines in an updated scoping study on the Cowboy State mine (CSM), in Wyoming, a larger development platform for a domestic source of rare earths in the US.

The study contemplates a 50%-higher throughput scenario at 4.5-million tonnes a year, with an estimated after-tax net present value of about $1.07-billion.

For a capital cost of $900-million, the expanded production at CSM can deliver average yearly neodymium and praseodymium (NdPr) oxide production of 2 500 t, marking a 36% increase compared with the company's 2025 base case scoping study of 1 800 t/y.

The updated study also estimates a 26-year mine life compared with a 20-year estimate previously.

The updated study incorporates a larger mine plan, more detailed engineering and revised cost estimates. It also adopts lower product recoveries and a higher capital contingency than the 2025 study, providing an updated basis for the next phase of project assessment.

American Rare Earths confirms through the study that a larger first phase within its broader Halleck Creek resource can be achieved. Halleck Creek hosts a mineral resource of about 2.63-billion tonnes grading 3 292 parts per million total rare earth oxides.

While the broader Halleck Creek mineral resource includes inferred mineral resources, the production target for CSM is based entirely on indicated mineral resources, with no inferred mineral resources or exploration target material having been scheduled as mill feed in the production target. The updated study is intended to evaluate an initial CSM mine plan, and not the development of the entire Halleck Creek resource.

American Rare Earths is currently working with Novex to evaluate the next step in the supply chain, which is converting rare earth oxide into metal. In particular, Novex has received a 50 kg concentrate sample for recovery optimisation work and a programme intended to progress the feedstock into NdPr metal.

In due course, the company will publish economics for its complete mine-to-magnet business.

"Our ambition is to turn Halleck Creek's resource scale into a long-term source of rare earth materials for American industry. This scoping study gives investors a clearer view of the first development phase and the work that is moving it forward.

"Just as important is the work beyond the study. We are testing how to recover more value from the ore, refining the infrastructure and processing configuration, and working with Novex on the pathway from oxide to metal. Our focus is on the decisions that can improve the project before major capital is committed," says American Rare Earths CEO Mark Wall.