Red Mountain Mining Highlights Copper Potential at Montana Tungsten Project
Key Takeaways
- Red Mountain's desktop study found copper rock chips up to 19.15% Cu at Mammoth, with 6.72% at Greenstone and 3.92% at Glow Worm, on top of confirmed tungsten skarn.
- This is a reinterpretation of assays already reported on 1 July and 14 September 2026, so no new sampling backs the copper story yet.
- Only 37 of 195 rock chips (19%) returned above 0.1% Cu, and Mammoth's 19.15% peak comes from just ten samples.
- Pioneer sits about 60km from Butte and adjacent to Almonty's Gentung deposit (6.83 Mt at 0.315% WO3), but Pioneer itself has no resource.
- Drilling is targeted for the 2027 Northern Hemisphere field season, subject to positive assays, while the company also reviews new copper asset opportunities.
Copper potential emerges at Pioneer Tungsten Project, with rock chips up to 19.15% Cu
A desktop study of previously reported sampling has put copper on the radar at a project known for tungsten. Red Mountain Mining (ASX: RMX, OTCQB: RMXFF) said the study confirmed tungsten skarn mineralisation across all sampled areas at its 100% owned Pioneer Tungsten Project in Montana, USA, and also highlighted multiple copper-rich rock chips of up to 19.15% Cu.
This is a reinterpretation, not fresh sampling. All assays were previously reported in announcements dated 1 July 2026 and 14 September 2026, and the company’s 15 October 2026 release focuses on the copper results within that dataset.
Of the 195 rock chip samples collected to date, 37 (19%) returned copper above 0.1% Cu. The remaining 158 assayed below 0.1% Cu.
What does that tell you? Copper may add a second commodity to a tungsten-focused project. The announcement discloses no new capital spend.
Key facts from the announcement:
- Maximum copper grade of 19.15% Cu at the Mammoth prospect
- 6.72% Cu at Greenstone and 3.92% Cu at Glow Worm
- 37 of 195 rock chips above 0.1% Cu
- Butte deposits sit about 60km northeast of Pioneer
- Drill testing is expected to commence during the 2027 Northern Hemisphere field season
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Where does the high-grade copper sit?
The high copper samples are concentrated at the Glow Worm prospect, the northern portion of the Greenstone prospect, and the Mammoth prospect. Historical artisanal mining at these sites recorded minor copper, silver and gold production in the early 20th century.
Greenstone and Glow Worm prospects
Rock chip sampling returned copper values of up to 6.72% Cu at Greenstone and 3.92% Cu at Glow Worm. The company said these high values are spatially associated with areas of mapped garnet skarn (a rock formed where hot intrusions alter carbonate-rich rocks).
Historical records show the Greenstone Mine reported production of 96 metric tonnes of copper ore across 1908, 1909 and 1949. That reportedly yielded 3.0t of copper, 4.3kg of silver and an ounce of gold.
At Glow Worm, exploration commencing in 1919 also targeted copper mineralisation, with six adits and four shallow shafts completed. There is no recorded production from those workings.
Mammoth prospect
Only ten rock chip samples have been collected at Mammoth, and two returned copper above 0.1% Cu. The maximum of 19.15% Cu came from a skarn outcrop.
The Ivanhoe Mine Claims in the Mammoth area produced 5.7t of copper, 18.3kg of silver and an ounce of gold from 79t of ore mined during 1928 and 1929. With so few samples, the Mammoth result is best read as an early reconnaissance signal.
| Prospect | Max Cu % | Sample context | Historical production | Notes |
|---|---|---|---|---|
| Greenstone | 6.72% | Rock chip; northern portion, associated with mapped garnet skarn | 96t ore (1908, 1909, 1949): 3.0t Cu, 4.3kg Ag, one ounce Au | Greenstone Mine |
| Glow Worm | 3.92% | Rock chip; central and southern portions, associated with mapped garnet skarn | No recorded production | Exploration from 1919; six adits, four shallow shafts |
| Mammoth | 19.15% | Rock chip from skarn outcrop | 79t ore (1928-1929): 5.7t Cu, 18.3kg Ag, one ounce Au | 10 samples collected, 2 above 0.1% Cu; Ivanhoe Mine Claims |
Why does Montana’s copper province matter?
What is skarn mineralisation?
Skarn forms where hot granitic intrusions react with carbonate rocks such as limestone. The process can produce minerals containing metals including tungsten and copper.
At Pioneer, the eastern margin of the Uphill Creek Granodiorite is in direct contact at surface with the Snowcrest Range Group. The company said the Snowcrest Range Group hosts both tungsten and copper skarn mineralisation at Pioneer when in contact with the granodiorite.
Proximity to Butte
Southwestern Montana is described in the announcement as a recognised globally significant copper province. The Butte deposits, hosted in the Boulder Batholith about 60km northeast of Pioneer, have an estimated total production and remaining resource of 37.9Mt Cu, 1.8Mt Mo, 45.7kt Ag and 79t Au.
Treat that as regional context only. Pioneer has no resource, and the Butte figures say nothing about the size of anything at Pioneer.
The tungsten backdrop
Tungsten remains the project’s established theme. Maximum rock chip WO3 results previously reported were:
- 0.55% WO3 at Greenstone
- 0.40% WO3 at Glow Worm
- 0.32% WO3 at Lost Creek
- 0.29% WO3 at Mammoth
The claims lie immediately adjacent to claims purchased in November 2025 by Almonty Industries, which include the Gentung Tungsten Deposit with a total mineral resource of 6.83 Mt @ 0.315% WO3. The announcement does not state that Pioneer holds a comparable resource.
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What are the next steps and portfolio plans?
Red Mountain’s exploration team is finalising plans for further mapping and sampling across Pioneer. The work will expand coverage beyond previously targeted areas and seek evidence of both tungsten and copper mineralisation.
The sequence outlined in the announcement is:
- Further mapping and surface sampling for tungsten and copper
- Prioritisation of targets for drill testing
- Drill testing, expected to commence during the 2027 Northern Hemisphere field season
Per the JORC table, drill testing of the downdip extension of surface mineralisation is subject to positive assay results.
The company is also reviewing new copper asset opportunities to increase exposure and complement its existing antimony and tungsten projects. This is a review only, and no transaction is disclosed.
For investors, the current portfolio comprises the Armidale Antimony-Gold Project, the Utah Antimony Project, the Thompson Falls Antimony Project and the Pioneer Tungsten Project.
Ready To Learn More About The Pioneer Tungsten Project?
Red Mountain Mining’s desktop study has put copper on the radar at Pioneer, with rock chips grading up to 19.15% Cu alongside confirmed tungsten skarn mineralisation. With drill testing expected in the 2027 Northern Hemisphere field season, the project’s dual-commodity potential is one to watch.
Explore the Red Mountain Mining company profile on Discovery Alert to see the latest updates across its tungsten and antimony portfolio. Find out how Pioneer fits into the company’s broader investment story.