ASX-listed Resolution Minerals on Wednesday announced a binding agreement to acquire the Horse Heaven antimony/gold/tungsten project in Idaho, US.

Horse Heaven is located in the historical Stibnite mining district and shares a boundary with the Stibnite gold/antimony project, owned by Nasdaq-listed Perpetua Resources.

Resolution will acquire the brownfield project for $1-million in cash and will issue 444.8-million shares and 222.4-million options exercisable at $0.018 each, expiring at the end of July 2028. The project was previously explored by TSX-V-listed Stallion Uranium.

The acquisition gives Resolution access to two prospective mineralised corridors –the Antimony Ridge Fault Zone (ARFZ) and Golden Gate Fault Zone (GGFZ) – with known gold, silver, antimony and tungsten mineralisation associated with sheared and hydrothermally altered granodiorite.

Highlight rock chip samples from the ARFZ include grades of up to 5.99 g/t gold, 367 g/t silver and 19.15% antimony. Historical drilling at the GGFZ returned intersections including 85.34 m at 0.937 g/t gold, with a higher-grade section of 38.10 m at 1.459 g/t.

The company noted that the GGFZ also hosted a historical, non-Joint Ore Reserve Committee-compliant resource of 216 000 oz of gold, while the ARFZ area hosts a 70 000 oz historical resource.

“The board considers that the acquisition of the Horse Heaven project has the potential to be a transformative event for RML,” said executive director Aharon Zaetz.

“As many governments around the world look to onshore their supply of critical minerals, such as antimony and tungsten, we have secured a commanding ground position with known antimony occurrences and next to what is likely to become the largest antimony producer in the US.”

Resolution intends to start drilling in 2025, targeting both corridors.

The company described Horse Heaven as complementary to its existing Australian antimony, gold and copper projects. It also pointed to the favourable market dynamics for critical minerals such as antimony and tungsten, with prices currently at record highs amid tightening export controls by China.

“RML’s entry into US critical minerals comes at a terrific time, with the market attributing huge premiums to ASX-listed companies operating in the space over the last eight weeks, such as Dateline Resources, Trigg Minerals and Locksley Resources which have all seen significant re-ratings in recent weeks, thanks to the supportive pro-mining policies of new President Donald Trump,” Zaetz added.

Once restarted, Perpetua’s Stibnite project is expected to become the only domestic producer of antimony in the US.