
Up to 13,700m of drilling across 45 holes targets gold and tungsten at Golden Gate North and South. Oxide leach tests return 94-95% gold recovery. First assays from the 2026 program are the next catalyst.
Resolution Minerals (ASX: RML) has started diamond core drilling at the Golden Gate area of its Horse Heaven antimony-tungsten-gold-silver project in Idaho, USA. An MP1500 diamond core drill rig is turning on the first hole of a 2026 program that could reach 13,700 metres across as many as 45 holes. The program launch coincides with initial metallurgical test work that returned gold recoveries of 94% to 95% from oxide leach tests and 86% to 88% from sulphide flotation tests.
The drill program is designed to define the scale and extent of gold mineralisation at Golden Gate North and Golden Gate South, test extensions of the broader system, and assess tungsten mineralisation around historical mine workings. The metallurgical results give Resolution a processing pathway for both oxide and sulphide material, reducing one layer of technical risk at a project that sits immediately adjacent to Perpetua Resources' Stibnite gold project.
The 2026 program is the most aggressive drill campaign Resolution has run at Golden Gate. The planned 13,700 metres across 45 holes will test two distinct target areas and follow up on historical tungsten production.
A key follow-up target is hole HH-GG25-001C, which previously returned 189.2 metres at 1.30 grams per tonne gold from 34.1m to 223.4m. That intercept started from surface and ended in mineralisation, leaving the system open at depth. The 2026 holes will step out from that collar to test the lateral and vertical continuity of the gold zone. Success here would move Golden Gate North toward a maiden resource estimate.
At Golden Gate South, a 500-metre by 600-metre target hosts a coincident gold and tungsten soil anomaly. Drilling here will test both metals simultaneously. The area has not been systematically drilled before, making it a genuine discovery target rather than a resource-definition exercise. The presence of tungsten adds a second revenue stream, though it also introduces metallurgical complexity.
Golden Gate has a history of tungsten production, with the most recent mining in 1980. The 2026 program will drill around the old mine workings to identify extensions of tungsten mineralisation. Composite samples from stockpiles stored at the Johnson Creek mill site have assayed 1.85% tungsten trioxide, confirming that high-grade tungsten material exists on the property.
Independent Metallurgical Operations in Perth conducted the initial test work on two composite samples prepared from 2025 diamond core. The results provide a clear processing route for both material types.
| Material | Test Type | Grind Size (µm) | Gold Recovery (%) | Concentrate Grade (g/t Au) | Residue Grade (g/t Au) |
|---|---|---|---|---|---|
| Oxide | Cyanide Leach | 150 | 94.2 | N/A | 0.04 (after 48h) |
| Oxide | Cyanide Leach | 75 | 95.5 | N/A | 0.04 (after 48h) |
| Sulphide | Rougher Flotation | 106 | 86.4 | 49 | N/A |
| Sulphide | Rougher Flotation | 75 | 88.7 | 26.4 | N/A |
Gold-bearing oxide samples with a composite feed grade of 0.55 g/t gold were subjected to direct cyanide leaching. At a grind size of 150 microns (µm), extraction reached 94.2% after 24 hours. A finer 75µm grind lifted extraction to 95.5%. After 48 hours, residue grades fell to 0.04 g/t gold, with recoveries ranging from 92.7% to 93.8%. The high recoveries at a relatively coarse 150µm grind suggest that a heap-leach operation could be viable for oxide material, keeping capital and operating costs low. The oxide composite weighed 21.4 kg and was taken from shallower material expected to have undergone significant weathering.
Gold-bearing sulphide samples with a composite feed grade of 1.91 g/t gold were subjected to rougher flotation testing. At a 106µm grind, recovery was 86.4%, producing a combined gold grade of 49 g/t. A finer 75µm grind increased recovery to 88.7%, although the gold grade decreased to 26.4 g/t due to higher silica recovery. The trade-off between recovery and concentrate grade is typical for sulphide flotation. The higher silica pull at finer grinds dilutes the concentrate grade, which would increase downstream processing costs. Further test work will now focus on reagent optimisation, followed by rougher, regrind, and cleaner testing to determine the optimum concentrate grade and recovery.
The sulphide composite represented material below the supergene zone and weighed 63.9 kg. Qualitative mineralogy by Diamantina Laboratories found the sample was approximately 90% quartz and more than 5% mica, with fresh sulphides including pyrite and arsenopyrite representing around 0.5%. The oxide sample was predominantly quartz with less than 10% sericitic mica and possible kaolin, with scanning electron microscopy detecting goethite, jarosite, scheelite, monazite, pyrite, and antimony-iron oxide inclusions.
Golden Gate is not a greenfields story. The area produced tungsten historically, with the most recent mining in 1980. Stockpiles at the Johnson Creek mill site assayed 1.85% tungsten trioxide, a grade that would be economic at current tungsten prices. The 2026 program will drill around the old workings to see whether the historical production only scratched the surface of a larger system.
Tungsten is a critical mineral with supply concentrated in China. A domestic US source would carry strategic value, and the Horse Heaven project's location in Idaho places it in a mining-friendly jurisdiction with existing infrastructure. For broader commodities trends, see commodities analysis.
The 2026 drill program will generate a steady flow of news. The first assay results from Golden Gate North and South are the nearest catalyst. Investors will watch for:
Resolution's board and major investors have visited the Horse Heaven project and witnessed the first drill hole of the season. The site visit included Golden Gate, the Johnson Creek mill, and Antimony Ridge, signalling that the company is treating 2026 as a defining year for the project.
The combination of a large drill program, high oxide recoveries, and a clear sulphide processing pathway gives Resolution a more concrete value proposition than it had before the metallurgical results. The market will now wait for the drill bit to confirm that the gold and tungsten mineralisation is as extensive as the geochemistry and historical data suggest. For more on gold market dynamics, see gold profile.
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