Red Mountain Mining Hits 0.55% WO3 at Pioneer Tungsten Next to AU$7B Neighbour
Key Takeaways
- 50 rock chip samples returned greater than 500ppm WO3 and 31 samples exceeded 1,000ppm WO3 across three prospects at Pioneer, with the best result hitting 5,473ppm (0.55%) WO3 at Greenstone — grades consistent with the adjacent Almonty Gentung Deposit (6.83Mt @ 0.315% WO3).
- Pioneer sits immediately adjacent to Almonty Industries' (NASDAQ: ALM, AU$7 billion market cap) Gentung Tungsten Deposit on the same Cretaceous Mount Torrey Batholith structural trend, providing a direct geological and valuation reference point.
- Polymetallic assays confirmed copper up to 6.72%, silver up to 462g/t, and gold up to 3.88g/t alongside the primary tungsten results, adding base and precious metal optionality to the project.
- The project footprint has more than doubled to 517 Ha since acquisition in late May 2026, with the Mammoth prospect — which returned up to 2,856ppm WO3 from initial reconnaissance — remaining largely unsampled ahead of the October field programme.
- Drill target prioritisation is the confirmed next step, with the southern Greenstone zone and northern Lost Creek identified as likely highest-priority targets, though no drill programme has been formally confirmed.
Strong tungsten and polymetallic assays across three prospects at Pioneer
Red Mountain Mining (ASX: RMX) has announced exceptional and consistent rock chip assay results from its 100% owned Pioneer Tungsten Project in Montana, USA, with 50 samples returning greater than 500ppm WO3 and 31 samples greater than 1,000ppm WO3 across three prospects: Greenstone, Glow Worm, and Lost Creek.
The best individual results came in at 5,473ppm (0.55%) WO3 at Greenstone, 4,036ppm (0.40%) WO3 at Glow Worm, and 3,241ppm (0.32%) WO3 at Lost Creek. Alongside those tungsten results, the programme also returned polymetallic highlights of up to 6.72% Cu, 462g/t Ag, and 3.88g/t Au. The project now covers 517 Ha, more than doubling the original footprint since acquisition in late May 2026, and sits immediately adjacent to Almonty Industries’ (NASDAQ: ALM, Market Cap AU$7 billion) Gentung Tungsten Deposit, which holds a total mineral resource of 6.83Mt @ 0.315% WO3.
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Q1 FY27 field results: prospect-by-prospect breakdown
Systematic rock chip sampling was focused on areas where published US Bureau of Mines mapping records outcropping garnet skarn. At all three prospects, there is a strong correlation between mapped garnet skarn and anomalous to mineralised tungsten results.
The outcropping tungsten skarn confirmation at Pioneer, reported ahead of the Q1 FY27 programme, established the surface geological framework that guided the systematic rock chip sampling approach across Greenstone, Glow Worm, and Lost Creek.
Greenstone
- 30 of 113 outcrop, float, and spoil samples returned >500ppm WO3; 17 samples returned >1,000ppm WO3; best result 5,473ppm (0.55%) WO3
- Tungsten mineralisation is most consistently developed along approximately 400m of strike immediately SSW of the Greenstone Mine Claim, associated with mapped garnet skarn — identified as a priority drill target
- The Greenstone Mine has reported historical production of 96 metric tonnes of copper ore in 1908, 1909, and 1949
- Copper and silver mineralisation are most strongly developed in the northern portion of Greenstone, with maximum values of 6.72% Cu and 462g/t Ag; gold peaked at 3.88g/t Au in this northern zone
- The southern portion of Greenstone shows consistently low copper, silver, and gold values, coinciding with where tungsten mineralisation is most strongly developed
Glow Worm
- Newly pegged prospect located approximately 1km north of Greenstone; garnet skarn mapped over a 700m strike extent
- 12 of 57 outcrop, float, and spoil samples returned >500ppm WO3; 8 samples returned >1,000ppm WO3; best result 4,036ppm (0.40%) WO3
- 7 of 23 soil samples returned >50ppm WO3 (maximum 383ppm) where no rock material could be located
- Notable base metal values in the southern and central portions: maximum 3.97% Cu and 199g/t Ag
Lost Creek
- 8 of 13 outcrop, float, and spoil samples returned >500ppm WO3; 6 samples returned >1,000ppm WO3; best result 3,241ppm (0.32%) WO3
- The Lost Creek Mine recorded historical production of 19kt at an average grade of 0.18% WO3 between 1952 and 1956
- Like the southern Greenstone zone, Lost Creek shows consistently low copper, silver, and gold values alongside high tungsten results — a potential indicator of a “tungsten-only” skarn environment
- The majority of the claim area remains unsampled; further mapping and sampling is planned for the October field programme
| Prospect | Best WO3 Result | Samples >500ppm WO3 | Samples >1,000ppm WO3 | Strike Extent of Mapped Skarn |
|---|---|---|---|---|
| Greenstone | 5,473ppm (0.55%) | 30 of 113 | 17 | ~400m (SSW of Greenstone Mine Claim) |
| Glow Worm | 4,036ppm (0.40%) | 12 of 57 | 8 | ~700m |
| Lost Creek | 3,241ppm (0.32%) | 8 of 13 | 6 | Extends into northwest corner of RMX ground |
What is tungsten skarn mineralisation — and why does it matter for investors?
Tungsten at Pioneer occurs as scheelite (CaWO4), a calcium tungstate mineral that forms within garnet skarns. Skarns develop where a hot igneous intrusion (in this case the Cretaceous Uphill Creek Granodiorite) contacts carbonate-rich sedimentary rock such as limestone. The heat and fluids from the intrusion drive metasomatic replacement of the carbonate rock, creating the distinctive garnet-rich skarn zones that host the tungsten mineralisation.
What makes the southern Greenstone and Lost Creek zones particularly noteworthy is the absence of copper, silver, and gold in the same samples that carry high tungsten values. The announcement notes that tungsten skarn mineralisation forms at a higher temperature than copper skarn mineralisation, so areas with “tungsten-only” geochemistry may indicate a portion of the skarn system with potentially higher prospectivity for economic-scale tungsten skarn development. Copper-rich samples may reflect retrograde skarn development during magmatic cooling, representing a lower-temperature and potentially less tungsten-enriched environment.
Tungsten is a critical mineral with strategic importance to Western supply chains. The Pioneer Project’s geological setting is directly comparable to the adjacent Almonty Gentung Deposit. Four aspects of the Pioneer geology stand out:
- Proven district — the Ivanhoe and Lost Creek mines collectively produced an estimated ~680kt of tungsten ore during the 1950s and from 1970 to 1975
- Consistent geology — Red Mountain’s prospects extend approximately 5km along the eastern margin of the Cretaceous Mount Torrey Batholith, the same structural setting that hosts the Gentung resource
- Surface-to-geology correlation — anomalous tungsten results correlate directly with mapped garnet skarn at all three sampled prospects, reducing geological uncertainty at surface
- Confirmed subsurface source — magnetic modelling undertaken by Arrow Geosciences indicates shallow subsurface magnetic bodies, interpreted to represent the granodiorite source of the skarn mineralisation beneath overlying limestone in the southern Greenstone area
Project expanded to 517 Ha — drill targets taking shape
Since acquiring the Pioneer Project in late May 2026, Red Mountain has staked additional prospective geology along the margin of the Mount Torrey Batholith, more than doubling the project footprint to its current size of 517 Ha. The expansion includes increased coverage over the Greenstone and Mammoth prospects and the addition of the Glow Worm prospect.
A fourth area, the Mammoth prospect, is located approximately 6km northwest of Lost Creek and remains largely unsampled. Initial reconnaissance rock chip sampling, reported on 1 July 2026, returned anomalous values of up to 2,856ppm (0.29%) WO3 at Mammoth, with further geological mapping and follow-up sampling planned for the October field programme.
Next steps across the project include:
- Further mapping and sampling at Greenstone and Lost Creek beyond the skarn extents mapped by Pattee (1960)
- Geological mapping and follow-up sampling at Mammoth (October field programme)
- Prioritisation of drill targets following completion of the surface sampling programme
- Based on results reported in this announcement, the southern portion of Greenstone and the northern portion of Lost Creek are identified as likely among the highest-priority targets for drill testing
The announcement is clear that drill target prioritisation will follow completion of the surface sampling work. No drill programme has been confirmed at this stage.
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Investment thesis: critical minerals, tier-1 address, transformative neighbour
Data Highlight
50 rock chip samples returned results above 500ppm WO3 — consistent with the grade profile of the adjacent Almonty Gentung Tungsten Deposit (6.83Mt @ 0.315% WO3).
The Pioneer results add substance to Red Mountain’s positioning as a critical minerals explorer with a purposeful US and Australian strategy. Pioneer is not an isolated play — it sits within a proven tungsten district, on the same geological trend as a AU$7 billion market cap neighbour’s flagship resource.
Key points for investors to consider:
- 100% owned project in Montana, USA — a Tier-1 mining jurisdiction
- Immediately adjacent to Almonty Industries’ (NASDAQ: ALM, Market Cap AU$7B) Gentung Tungsten Deposit (6.83Mt @ 0.315% WO3)
- Polymetallic upside confirmed, with copper, silver, and gold assays alongside the primary tungsten target
- Project footprint more than doubled since acquisition; the Mammoth prospect remains largely unsampled
- Drill target prioritisation anticipated following completion of the current surface sampling programme
Beyond Pioneer, Red Mountain’s broader critical minerals portfolio includes the Armidale Antimony-Gold Project in NSW, Australia; the Utah Antimony Project; the Thompson Falls Antimony Project in Montana; and the Yellow Pine Antimony Project in Idaho — all positioned in established US and Australian mining districts.
Ready to Explore the Pioneer Tungsten Project’s Drill Target Potential?
Red Mountain Mining’s (ASX: RMX) Pioneer Project in Montana has delivered compelling rock chip assay results across three prospects, with grades consistent with the adjacent Almonty Gentung Deposit — a resource held by a neighbour with an AU$7 billion market cap. The 517 Ha, 100% owned project also carries polymetallic upside, with copper, silver, and gold confirmed alongside the primary tungsten targets.
For a full breakdown of the prospect-by-prospect results and what comes next as drill targets are prioritised, explore the Red Mountain Mining project profile on Discovery Alert to stay ahead of developments at Pioneer.