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RED MOUNTAIN MINING LIMITED
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Red Mountain Mining Limited (RMXFF) Further Strong Tungsten and Copper Assays at Pioneer Project

2026-09-13 18:56 ET - News Release

Perth, Australia, Sep 14, 2026 - (ABN Newswire) - Red Mountain Mining Limited (ASX:RMX) (OTCMKTS:RMXFF), a Critical Minerals exploration and development company with an established portfolio in Tier-1 Mining Districts in the United States and Australia, is pleased to announce outstanding assay results from a program of systematic rock chip sampling at the Company's 100% owned Pioneer Tungsten Project, in Montana, USA. Exceptional and consistent results were received with 50 rock chip samples over 500ppm WO3, and 31 samples over 1,000ppm WO3, with the best values of 0.55% WO3 at Greenstone 0.40% WO3 at Glow Worm and 0.32% WO3 at Lost Creek. Precious Metals and Base Metals assay results also received from Greenstone and Glow Worm, showed evidence of the project's strong polymetallic prospectivity, with results of up to 6.72% Cu, 462g/t Ag and 3.88 g/t Au.

HIGHLIGHTS:

- Pioneer Tungsten Project in Montana, USA, has returned exceptional and consistent results with 50 rock chip samples over 500ppm WO3, and 31 samples over 1,000ppmWO3, with the best values of o 5,473ppm (0.55%) WO3 at Greenstone

o 4,036ppm (0.40%) WO3 at Glow Worm and
o 3,241ppm (0.32%) WO3 at Lost Creek.

- Exceptional Precious Metals and Base Metals assay results also received from Greenstone and Glow Worm, showing evidence of the project's strong polymetallic prospectivity, with results of up to

o 6.72% Copper
o 462g/t Silver and
o 3.88 g/t Gold

- These results confirm the highly prospective nature of the project for Tungsten mineralisation with the claims encompassing similar geology and positioned adjacent to Almonty Industries' (Market Cap AU$7 billion) Gentung Tungsten Deposit, with a mineral resource of 6.83Mt @ 0.315% WO3; as well as the Ivanhoe and Lost Creek Mines, which are estimated to have collectively produced 680kt of Tungsten ore in the 1950s and 1970s.

- Red Mountain's Greenstone, Glow Worm and Lost Creek prospects collectively extend approximately 5km along the eastern margin of the Cretaceous Mount Torrey Batholith, which locally features massive limestone-hosted garnet skarns, up to 25m thick. These skarns are known to contain tungsten mineralisation as scheelite (CaWO4).

- Red Mountain's Pioneer Tungsten Project, which also includes the Mammoth prospect, approximately 6km northwest of Lost Creek, has been expanded to cover a total of 517 Ha of prospective geology, more than doubling the original project footprint.

- The majority of Red Mountain's Mammoth and Lost Creek prospects remain unexplored and will be sampled during the Company's next field program, planned for October.

Following the execution of the agreement in late May that secured ownership of the Pioneer Project, Red Mountain has staked additional prospective geology along the margin of the Mount Torrey Batholith and has more than doubled the project footprint to its current size of 517 Ha, with expanded coverage over the Greenstone and Mammoth prospects and the addition of a new prospective area, the GlowWorm prospect, which lies approximately 1km north of Greenstone and 4km south of the Lost Creek prospect (Figure 1*).

Red Mountain's systematic rock chip sampling was focused on areas within the Lost Creek, Glow Worm and Greenstone prospects, where published US Bureau of Mines mapping records outcropping garnet skarn. Sampling was carried out on east-west traverses at a nominal line spacing of 50m and, where possible, sample spacing of 5m over the area of mapped skarn, with a handful of additional samples collected between these areas where potentially altered or mineralised rocks were identified (Figure 2* and Figure 3*). Due to the predominance of steep terrain and often thick living vegetation and leaf litter cover across the Projectarea, it was often difficult to confidently identify outcropping material away from historical workings and excavations. Where outcropping material could not be located, float or workings spoil samples were collected, if available. In addition, forthe Glow Worm prospect, soil samples were collected where no rock material could be located (Figure 3) and two stream sediment samples were collected south of Greenstone (Figure 2). Sample locations and details, along with tungsten/tungstate, gold, silver, copper, lead, zinc and molybdenum assay results are provided in Appendix 1.

Consistent and Strong Assays demonstrate Tungsten Mineralisation at Pioneer

Tungstate (WO3) assay results for samples from Greenstone, Glow Worm and Lost Creekare shown on Figure 4* and Figure 5*. To allow quick visual comparison of stream sediment and soil sample results to rock chip (outcrop, float and spoils) results, symbology ranges for the stream and soil samples have been set an order of magnitudelower than for the rocks.

At all three sampled prospects, there is a strong correlation between the distribution of mapped garnet skarn after Pattee (1960) and strongly anomalous (>500ppm WO3 in outcrop, float and spoils) to mineralised (>1000ppmWO3 in outcrop, float and spoils) tungsten results.

At Greenstone, 30 of 113 outcrop, float and spoil samples collected contain >500ppm WO3, with 17 of these containing >1,000ppm (0.1%) WO3, and up to 5,473ppm (0.55%) WO3. As can be seen on Figure 4, tungsten mineralisation is most consistently developed along a strike extent of approximately 400m immediately SSW of the Greenstone Mine Claim, where it is associated with mapped garnet skarn. This area was identified as a potential drill target by Red Mountain during the Company's due diligence for the Pioneer Project and remains a priority target for drill testing.

The Glow Worm area was also identified by Red Mountain as prospective for tungsten mineralisation during due diligenceand the area has subsequently been pegged and granted. Like the Greenstone Prospect ~1km to the south, Glow Worm was initially prospected in the first half of the 20th century for copper mineralisation, and features at least six adits and four shallow shafts that are thought to date from this phase of exploration (Pattee, 1960). In 1952 and 1953, five bulldozer trenches and several pits were dug to prospect for tungsten.

As can be seen on Figure 5, garnet skarn is mapped by Pattee (1960) over a strike extent of 700m at Glow Worm. Twelve of 57 outcrop, float and spoil samples collected from the prospect contain >500ppm WO3, with eight of these containing >1000ppm (0.1%) WO3, and up to 4,036ppm (0.40%) WO3. In addition, seven of the 23 soil samples, collected where it was not possible to locate rock samples, contain over 50ppm WO3, with a maximum value of 383ppm WO3. Tungsten mineralisation is most consistently developed in the central and southern portions of the mapped garnet skarn, where it appears to be thinner than further to the north, potentially indicating a zone of more concentrated hydrothermal flow.

The Lost Creek Mine has recorded production from a series of adits and small open pits of 19kt at an average grade of 0.18% WO3 between 1952 and 1956. The current Lost Creek Mine Claim lies immediately north of Red Mountain's Lost Creek claim area, but the mine workings and the area of skarn mapped by Pattee (1960) extend into the northwest corner of Red Mountain's ground (Figure 5). The contact between the Uphill Creek Granodiorite and the Snowcrest Range Group limestone is mapped by the USGS as extending down the full length of the Company's Lost Creek claim area (Figure 5), so this unsampled area remains highly prospective.

Eight of 13 outcrop, float and spoil samples collected across and close to the mapped garnet skarn at Lost Creek contain >500ppm WO3, with six of these containing >1,000ppm (0.1%) WO3, and up to 3,241ppm (0.32%) WO3. These results highlight the strong potential of the Lost Creek prospect for tungsten mineralisation and further mapping and sampling is planned across the remainder of the prospect.

Exceptional Precious and Base Metal mineralisation results

As can be seen in Appendix 1*, a significant number of rock samples from Glow Worm and the northern portion of Greenstone returned highly anomalous results for base and precious metals, particularly for copper (Figure 6), silver (Figure 7), and gold (Figure 8).These results show evidence of the area's polymetallic prospectivity and are consistent with its early mining history, which saw prospecting and small-scale production of these metals, in particular copper.

Copper (Figure 6*) and Silver (Figure7*) mineralisation are best developed in the northern portion of the Greenstone prospect, along the western margin of the Greenstone Mine Claim, with maximum values of 6.72% Cu and 462 g/t Ag. The Greenstone Mine has reported historical production of96 metric tonnes of copper ore in 1908, 1909 and 1949, which reportedly yielded 3,032lb of copper, 4.3kg of silver and an ounce of gold. Copper is also consistently found in samples from the southern and central portions of the Glow Worm prospect, where it is also associated with early 1900s shaft and adit development. The maximum recorded values for Glow Worm are 3.97% Cu and 199 g/t Ag.

Gold mineralisation (Figure 8*) is most consistently developed for the northern portion of Greenstone,which returned a maximum value of 3.88 g/t Au. It is less well-developed at Glow Worm, which returned below detection limit results for most samples and a maximum value of 0.81 g/t Au.

As can be seen on Figures 6 to 8, the southern portion of theGreenstone prospect, where tungsten mineralisation is most strongly developed (Figure 4) shows consistently low values for copper, silver and gold. The same is true for all samples collected from the Lost Creek prospect, which like the southern partof Greenstone, shows consistently high tungsten results (Figure 5). This absence of other metals may be an indicator that these two areas are within a portion of the skarn system that is "tungsten only" and therefore potentially of higher prospectivity for economic-scale tungsten skarn development. Tungsten skarn mineralisation is known to form at a higher temperature than copper skarn mineralisation, so the copper-rich samples may be a reflection of retrograde skarn development during magmaticcooling.

Next steps for Pioneer

As can be seen on Figure 1, as well as the more detailed figures in this announcement, USGS mapping shows that the prospective Snowcrest Range Group, which hosts the tungsten skarn mineralisation at Pioneer when in contact with the Uphill Creek Granodiorite, extends well beyond the area mapped by Pattee (1960) throughout the strike length of Red Mountain's claims at Greenstone, Lost Creek and Mammoth. At Lost Creek and Mammoth, Snowcrest Range limestone is shown in contact with the Granodiorite at surface throughout the claim area, which implies potential for additional skarn development at the surface. In the southern part of the Greenstone area, the limestone is not in direct contact with the Granodiorite at surface. However, as reported in June, magnetic modelling undertaken by Arrow Geosciences, indicates shallow subsurface magnetic bodies, interpreted to represent the granodiorite source of the skarn mineralisation beneath the overlying limestone.

During the current field season, Red Mountain's exploration team will undertake further mapping and sampling beyond the areas of skarn mapped by Pattee (1960) at Greenstone and Lost Creek to define additional areas with potential for tungsten skarn mineralisation. Further geological mapping and follow-up sampling is also planned for Mammoth, where initial reconnaissance rock chip sampling, reported on 1 July, returned anomalous values of up to 2,856ppm (0.29%) WO3.

Following completion of the surface sampling program, Red Mountain will prioritise targets for drill testing. Based on the results reported in this announcement, it is likely that the southern portion of Greenstone and the northern portion of Lost Creek will be among the highest priority targets for drilling.

Pioneer Project geology

The Pioneer Tungsten Project claims cover four discrete locations, the Greenstone, Glow Worm, Mammoth and Lost Creek prospects, where the eastern margin of the Uphill Creek Granodiorite is in direct contact at surface with the Snowcrest Range Group (Figure 1). Red Mountain's claims encompass Tungsten-bearing skarn mineralisation mapped and sampled in the middle of last century and a number of historical workings stillvisible today. The claims also lie immediately adjacent to claims purchased in November 2025 by Almonty Industries (NASDAQ:ALM) (TSE:AII) (ASX:AII) (FRA:ALI1); Market Cap AU$7 billion), which include the Gentung Tungsten Deposit, which has a total mineral resource of 6.83 Mt @ 0.315 % WO3 32; as well as the Ivanhoe and Lost Creek Mines, which are estimated to have collectively produced 680kt of tungsten ore in the 1950s and from 1970 to 1975.

In addition to the exposures of garnet skarn atsurface, Red Mountain's claims also have clear geological potential for limestone-hosted tungsten-bearing garnet skarn mineralisation at shallow depths beneath overlying quartzite units, where magnetic modelling undertaken by Arrow Geosciences, indicates subsurface magnetic bodies, interpreted to represent the granodiorite source of the skarn mineralisation.

The Torrey Batholith is a large volume composite complex that forms the core of the Pioneer Mountains in southwest Montana. The batholith ranges in composition from gabbro to granite, but is dominantly granodioritic in composition. Tungsten mineralisation occurs along the entire eastern contact of the Pioneer Batholith where it is in contact with mid-Palaeozoic carbonate-rich sedimentary rocks (Figure 1), but to date significant mineralisation, occurring in scheelite-bearing massive garnet skarns, has only been found where the limestones of the Snowcrest Range Group contact the Uphill Creek Granodiorite. Significantly, there does not appear to be any skarn development or tungsten mineralisation associated with the Grayling Lake Granite, which cuts and is therefore younger than the granodiorite and associated skarn mineralisation at the Mammoth Prospect.

Historical Tungsten Production

The earliest recorded interest in the garnet skarn hosted tungsten mineralisation surrounding the Mount Torrey Batholith dates from the early 1950s, driven by the US Federal Government's strategic metal stockpiling program, with significant production recorded from the Ivanhoe and Lost Creek mines (Figure 1). Exploration for tungsten was carried out between 1951 and 1953 around the Ivanhoe Mine (also known as the Brown's Lake Mine), which had been mined for copper, silver andgold in 1928 and 1929, recording production of 5.7t Cu; 647 oz Ag and 1 oz Au. Open pit tungsten production from the Ivanhoe Mine commenced in October 1953 and initially ceased in 1957, with total production during this period of 567kt at an averagegrade of 0.35% WO3. Similar skarn-hosted tungsten mineralisation was mined by the Minerals Engineering Company between 1952 and 1956 from a series of adits and small open pits at the Lost Creek Mine, ~5km southeast of Ivanhoe. The total recorded production from Lost Creek during this period is 19kt at an average grade of 0.18% WO3. Both mines remained idle until 1971, when General Electric purchased the properties and rebuilt the mill at Ivanhoe, which operated until 1975. Minor Tungsten production is also recorded from the Greenstone Mine during the 1950s, with recorded production of 900kg of sorted ore, containing 1.2% WO3. It is estimated that total production from the district from the 1950s and 1970s is approximately 680kt of tungstenore.

*To view tables and figures included in the announcement, please visit:
https://abnnewswire.net/lnk/8ZSC9984

About Red Mountain Mining Limited:

Red Mountain Mining Limited (ASX:RMX) is a mineral exploration and development company. Red Mountain has a portfolio of US, Canada and Australia projects in Critical Minerals and Gold. Red Mountain is advancing its Armidale Antimony-Gold Project in NSW, Utah Antimony Project in the Antimony Mining District of Utah, US, Fry Lake Gold Project and US Lithium projects.

Contact:

 
Mauro Piccini 
Company Secretary