- 01RML targets US antimony and tungsten at Idaho’s Horse Heaven.
- 02100%-owned since June 2025; 729 claims span 14,580+ acres.
- 03Rock chips graded up to 50% antimony.
Mineral exploration company Resolution Minerals (ASX: RML) (NASDAQ: RML) is directing its primary exploration activities toward the Horse Heaven gold-antimony-tungsten project in Valley County, Idaho, USA.
The company acquired a 100% interest in the project in June 2025, aiming to establish a potential supply of domestic antimony and tungsten to support industrial and defence sector supply chains in the US.
Company Background
Resolution Minerals is an ASX and NASDAQ-listed exploration issuer with an executive team led by executive directors Aharon Zaetz and Mendel Rogatsky, along with non-executive directors Brett Lynch, a well-known operator with a track record of success in North America, and Syed Hizam Alsagoff.
The company’s North American operational footprint is supported by a US-based management team, including chief executive officer for US operations Craig Lindsay, chief operating officer Steve Rieber, and technical lead Bill Breen.
Resolution has structured its recent operational strategy around advancing North American mineral assets, seeking to align exploration activities with domestic supply chain initiatives for critical raw materials.
On a parallel basis, it is developing an emerging gold deposit at Horse Heaven in mineralization associated with its tungsten and antimony.
Horse Heaven Project Context
The Horse Heaven project comprises 729 federal lode mining claims spanning over 14,580 acres in a historic mining district near Cascade, Idaho.
The tenement holding shares its eastern boundary with the fully-permitted Stibnite Gold Project owned by Perpetua Resources.
According to company information, the property encompasses several past-producing antimony and tungsten, as well as multiple district-scale exploration targets:
- Golden Gate Prospect: Historical exploration at Golden Gate Hill documented non-JORC compliant historical gold resource estimates comprising 216,000 ounces of gold across approximately 7.25 million tons at an average grade of 0.93 g/t Au, alongside a historical estimate of 70,000 ounces of gold at Antimony Hill. Historical mining at the prospect between the 1950s and 1980s also produced tungsten from the Golden Gate Tungsten Mine, which began as an open pit and then went underground.
- Antimony Ridge Prospect: The target area incorporates historic small-scale open pit operations within approximately 1,000m of trenches that produced antimony across periods spanning World War I, World War II, and the early 1950s.Surface rock-chip sampling conducted by the company returned grades up to 50% antimony (Sb), 1,420 g/t silver (Ag), and 3.1 g/t gold (Au).
The project benefits from regional infrastructure upgrades associated with local development, including road access from nearby Cascade, Idaho and a new transmission line being installed in connection with the adjacent Stibnite Gold Project.
Operational Progress
According to corporate disclosures and updates provided by Resolution Minerals:
- Drilling Campaigns: The company completed a maiden 14 hole diamond and reverse-circulation (RC) drilling program at the project in 2025, reporting that drilling successfully tested mineralised zones across the Golden Gate and Antimony Ridge prospects. In 2026, the company reports that it has completed a further 12,000m of diamond core drilling across 42 drill holes at Golden Gate.
- Assay Results: Laboratory results from field sampling and drilling campaigns confirmed surface gold and antimony mineralisation, with assays extending historical mineralised trends at the Golden Gate target. In connection with its 2026 drill campaign, assays have been released from 6 holes with results from a further 36 holes pending.
- Processing Infrastructure Strategy: Corporate updates stated that the company acquired the Johnson Creek Mill and Antimony Camp, located immediately adjacent to its Horse Heaven Project, securing access to a 25-acre private site housing a formerly operational antimony-tungsten mill facility.
- US Government Support: The company has announced that both the Antimony Ridge and Golden Gate Prospects have received FAST-41 coverage by the US Permitting Council, potentially accelerating permitting timelines for ongoing and future development activities.
- Dual-Listing: The company announced the commencement of trading on the NASDAQ market in the US to increase market exposure to North American institutional and retail investors.
Critical Minerals and Antimony Demand
Antimony and tungsten are classified as critical minerals by multiple international governments, including the US, due to their industrial applications in defence tech, flame retardants, semiconductors, and clean energy storage technologies.
Because North American industries currently depend heavily on imports for raw antimony feedstock, US government policy initiatives have increasingly focused on securing domestic supply chains and supporting domestic extraction and processing capability.
Proximity to existing regional infrastructure and established mineral belts in mining-friendly jurisdictions like Idaho remains a central focus for mineral exploration issuers in the sector.
Summary
Resolution Minerals is progressing exploration and development activities across its Horse Heaven gold-antimony-tungsten project in Idaho.
By focusing field operations on historical mining targets and advancing technical studies alongside processing option agreements, the company continues to evaluate the potential of its US critical minerals portfolio.
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