Red Mountain Mining (ASX: RMX) reported strong exploration momentum across its US and Australian portfolio during the December 2025 quarter, led by expanded land positions and multiple new antimony targets.
The company completed detailed geological mapping across its Utah antimony project, confirming host rocks and alteration styles consistent with high-grade antimony mineralisation seen at the nearby Antimony Canyon district.
Red Mountain expanded the project footprint to 106 claims after securing an additional 19 claims covering the southern extension of these key fault corridors.
Multispectral satellite analysis by consultant Dirt Exploration defined 100 high-priority surface spectral targets across the project area, while gas and mercury vapour datasets also identified targets beneath cover, supporting the potential for concealed antimony mineralisation along mapped fault trends.
Idaho Antimony Projects Build Strategic Scale
At the Yellow Pine antimony project in Idaho, Red Mountain increased its landholding by 75% to 426 hectares after recognising potential for undiscovered gold and antimony mineralisation during early reconnaissance work.
The project lies less than 2 kilometres from Perpetua Resources’ Stibnite gold-antimony project, which hosts the largest known antimony deposit in the USA.
Geological mapping indicates Red Mountain’s claims cover similar metasedimentary and intrusive units cut by regional fault systems known to control antimony-gold-tungsten mineralisation in the district.
At the Silver Dollar antimony-silver project, the company outlined historical high-grade stibnite vein mineralisation, including reported grades equivalent to approximately 17.7% antimony.
Structural interpretation suggests these veins are linked to fault systems analogous to those hosting mineralisation at Stibnite, supporting potential for further discoveries.
Large Antimony-Gold System at Armidale
Red Mountain continued aggressive exploration at its Armidale antimony-gold project in New South Wales, Australia’s premier antimony province.
Soil, auger, and rock-chip sampling at Oaky Creek outlined a coherent orogenic antimony-gold system extending over 3km of strike, returning antimony values of up to 39.3% with associated gold mineralisation and confirming the presence of high-grade material at surface.
Follow-up auger sampling defined strong antimony and arsenic anomalies that remain open along strike, reinforcing the scale potential of the system.
Initial soil results at East Hills also confirmed antimony and gold anomalism, although Oaky Creek remains the company’s highest priority target.
Corporate Positioning And Outlook
Red Mountain raised $1.35m during the quarter through an oversubscribed placement supported by professional and sophisticated investors.
The transaction involved the placement of approximately 52 million shares at a 13 per cent discount to the last sale of $0.03 at that time, with participants entitled to receive 1-for-2 attaching unlisted options at an exercise price of $0.05 and expiry of 31 December 2028.
The company also commenced trading on the OTCQB market in the US under the code RMXFF, increasing its exposure to US investors.
With multiple antimony projects now advanced to the target-definition stage, Red Mountain plans further surface work, geophysics and initial drilling during the first half of 2026.
