Red Mountain Mining Ltd (ASX: RMX) — Outcropping Garnet Skarn Identified and Magnetic Modelling Highlights Significant Potential at Pioneer Tungsten Project, Montana

9 June 2026

Price Sensitive Announcement $

Highlights:

• Red Mountain’s US field team has confirmed outcropping garnet skarn at both the Mammoth and Greenstone prospects within the Company’s 100% owned Pioneer Tungsten Project in Montana, USA
• The Pioneer Tungsten Project comprises three claim areas — Greenstone, Mammoth and Lost Creek — located along the eastern margin of the Mount Torrey Batholith, where massive limestone-hosted garnet skarns up to 25m thick are known to contain tungsten mineralisation as scheelite (CaWO4)
• 24 rock chip samples collected from Mammoth and Greenstone have been submitted for multielement analysis to confirm the presence of tungsten mineralisation, with results expected before end of June
• Magnetic modelling by Arrow Geosciences reveals subsurface magnetic bodies beneath the Greenstone and Mammoth claims, interpreted to represent shallow extensions of the granodiorite source of skarn mineralisation — indicating clear geological potential for tungsten-bearing garnet skarn at drillable depths
• RMX’s claims lie immediately adjacent to claims purchased in November 2025 by Almonty Industries (Market Cap AU$6.6 billion), which host the Gentung Tungsten Deposit with a mineral resource of 6.83Mt @ 0.315% WO3, as well as the Ivanhoe and Lost Creek Mines, which collectively produced an estimated 680kt of tungsten ore in the 1950s and 1970s
• Subject to positive analytical results, the Company expects to move rapidly to define drill targets and secure the necessary approvals to execute a drilling program during the current northern hemisphere summer
• Further reconnaissance mapping and surface sampling across all three claim areas is planned for June

Overview:

Red Mountain Mining has delivered a significant exploration update from its Pioneer Tungsten Project in Montana, with field crews confirming outcropping garnet skarn at both the Mammoth and Greenstone prospects and magnetic modelling pointing to shallow subsurface extensions of the tungsten-prospective granodiorite beneath the Company’s claims.

The Pioneer Tungsten Project sits along the eastern margin of the Mount Torrey Batholith — a district with a well-established history of tungsten production and a highly credible geological setting for skarn-hosted mineralisation. Most significantly, RMX’s claims sit immediately adjacent to Almonty Industries’ recently acquired Gentung Tungsten Deposit, which carries a mineral resource of 6.83Mt @ 0.315% WO3 and lies at approximately 200m depth on a near flat-lying contact between Snowcrest Range Group limestone and the Uphill Creek Granodiorite — the same geological configuration present beneath Red Mountain’s Mammoth and Greenstone claims.

Magnetic modelling completed by Arrow Geosciences using USGS airborne magnetic data has identified subsurface magnetic ridges beneath both Mammoth and Greenstone that are spatially consistent with shallow extensions of the Uphill Creek Granodiorite — the interpreted fluid source for skarn tungsten mineralisation across the district. At Greenstone, there is a direct spatial relationship between the modelled magnetic high and mapped garnet skarn at surface, strengthening the case for drill testing of down-dip extensions. The Lost Creek prospect, by contrast, shows a steeply dipping granodiorite margin, making it less immediately prospective for shallow skarn targets.

With 24 rock chip samples already submitted and results expected before the end of June, Red Mountain is positioned to move quickly into drill target definition at one or more prospects if analytical results confirm tungsten grades consistent with the district’s known mineralisation. Additional surface mapping and sampling across all three claim areas is planned this month to further refine targets ahead of permitting.

About Red Mountain Mining Ltd (ASX: RMX):

Red Mountain Mining Limited is a Critical Minerals exploration and development company with an established portfolio in Tier-1 Mining Districts in the United States and Australia. In Australia, the Company’s flagship Armidale Antimony-Gold Project spans an 85km corridor in the Southern New England Orogen of New South Wales, sitting in close proximity to Larvotto Resources’ Hillgrove deposit — Australia’s largest known antimony deposit and the 8th largest globally. In the United States, Red Mountain holds the Pioneer Tungsten Project in Montana, comprising the Greenstone, Mammoth and Lost Creek prospects along the eastern margin of the Mount Torrey Batholith — a historically productive tungsten district now attracting renewed interest from major producers including Almonty Industries.

Full ASX Announcement: Red Mountain Mining Full ASX Announcement