Why Resolution Minerals’ Idaho Project Could Transform Its Future

Strategic Acquisition in a Historic Mining District

Resolution Minerals Ltd (ASX, RML) has announced a binding agreement to acquire the Horse Heaven Project, a major antimony-gold-silver-tungsten exploration asset located in the historic Stibnite Mining District of central Idaho, USA. This brownfields project lies directly adjacent to the Stibnite Gold Mine owned by Perpetua Resources Corp, a NASDAQ-listed company with a market cap of approximately A$2 billion.

The Horse Heaven Project covers 5,644 hectares and includes 699 U.S. Federal lode mining claims. It hosts two principal mineralised corridors, the Antimony Ridge Fault Zone (ARFZ) and the Golden Gate Fault Zone (GGFZ). Both zones have demonstrated significant mineralisation through historical drilling, trenching, and rock chip sampling, indicating the potential for large tonnage deposits of gold, antimony, silver, and tungsten.

Encouraging Historical Data and Exploration Potential

Historical exploration at Horse Heaven spans over a century, with intermittent mining of antimony and tungsten dating back to the early 20th century. Notably, tungsten was produced at Golden Gate Hill between the 1950s and 1980s, while antimony shipments occurred during both World Wars. More recent exploration by Stallion Uranium Corp included detailed trench mapping, rock chip sampling, and a Controlled Source Audio-frequency Magnetotelluric (CSAMT) geophysical survey, revealing broad zones of mineralisation.

Rock chip samples from Antimony Ridge have returned impressive grades, including up to 5.99 g/t gold, 367 g/t silver, and 19.15% antimony over narrow intervals. Drilling results at Golden Gate Hill show broad gold mineralisation intervals, such as 152 meters at 0.94 g/t gold from surface, highlighting the project's large tonnage potential. However, these historical resource estimates are non-JORC compliant and considered immaterial by the company, pending further exploration.

Planned Drilling and Development Pathway

Resolution Minerals plans a significant 2025 exploration program, including up to 6,000 meters of drilling focused on the Golden Gate prospect, complemented by additional soil surveys and metallurgical testing. The drilling will target depths up to 300 meters, representing the deepest holes drilled to date at Horse Heaven. The company aims to upgrade the historical resource estimates to JORC-compliant standards, a critical step towards defining economic mineral resources.

The acquisition consideration includes AUD 1 million in cash and over 444 million shares, alongside options, supported by a $1.9 million placement to sophisticated investors. Oakley Capital Partners Pty Limited acts as lead manager and corporate advisor, with fees subject to shareholder approval. Completion of the acquisition is conditional on due diligence, shareholder approvals, and regulatory consents, expected by August 2025.

Strategic Timing Amid Rising Critical Mineral Demand

The Horse Heaven Project acquisition strategically positions Resolution Minerals within the US critical minerals sector, particularly for antimony and tungsten; commodities experiencing record high prices amid tightening Chinese export controls. The project’s proximity to the soon-to-reopen Stibnite Gold Mine, which is expected to become the only domestic US source of antimony, enhances its strategic value.

Executive Director Aharon Zaetz highlighted the transformative potential of this acquisition, noting the global push for onshoring critical mineral supply chains. The company’s entry into the US market aligns with recent re-ratings of ASX-listed critical minerals companies, driven by supportive US policies under the Trump administration.