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RED MOUNTAIN MINING LIMITED
Symbol	RMXFF
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Red Mountain Mining Limited (RMXFF) Drilling Completed at Armidal Antimony-Gold Project

2026-09-22 17:57 ET - News Release

Perth, Australia, Sep 23, 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, announced the completion of the maiden reversecirculation (RC) drilling program at the Company's Oaky Creek antimony prospect, west of Armidale in northeastern NSW.

HIGHLIGHTS:

- Drilling has successfully completed at Red Mountain's maiden reverse circulation (RC) drilling program at the Oaky Creek Antimony Prospect, west of Armidale in New South Wales.

- 20 holes, totaling 1776m, were completed into four priority targets defined by the Company's extensive surface geochemical sampling program at Oaky Creek.

- Sample splitswere screened on site using a portable XRF (pXRF) to prioritise samples for laboratory analysis, with 578 one-metre intervals from 19 of the 20 holes completed submitted to Intertek for four-acid digest multielement analysis and gold analysis by fire assay.

- Assay results for the samples are expected to be received by mid-November.

- Oaky Creek is Red Mountain's most advanced target within the 391 km2 Armidale AntimonyGold Project, located in the Southern New England Orogen of NSW, considered to be Australia's premier antimony mineral province. Previously announced conventional and auger soil sampling and rock chip analytical results of up to 39.3% Sb and 1.09ppm Au from Oaky Creek indicate potential for a large-scale orogenic antimony-gold vein system with a strike extent of ~3km at surface, which is analogous to Larvotto Resources' Hillgrove project, Australia's largest known antimony deposit.

A total of 20 RC drillholes, totaling 1776m, were completed to test four of five priority orogenic antimony-gold targets defined from Red Mountain's comprehensive surface rock chip, conventional soil and auger soil sampling program, completed over the past 12 months (Figure 1; Table 1). In summary, the drilling comprised:
- Ten drillholes into the coherent 300m x 30m Oaky Creek South Main Grid antimony-arsenic auger soil anomaly, which has also returned surface rock chip results of up to to 39.3% Sb & 1.09ppm Au.

- Three drillholes beneath the historical workingsand outcropping quartz-carbonate-stibnite veins at the Oaky Creek North Workings.

- Four drillholes to test beneath the Sb-bearing Creek exposure to the north of the Oaky Creek North Workings.

- Three drillholes to test the historical workings, outcropping quartz-carbonate-stibnite veins and associated IP chargeabilty anomaly at the Oaky Creek South Workings.

Due to the presence of crops in the ground, Red Mountain's fifth target - the geochemical target at the Oaky Creek North South Extension - was not accessible for drilling.

During the drilling program, Red Mountain's field team utilised a portable XRF (pXRF) instrument in combination with visual geological logging to select one-metre drill sample splits for laboratory analysis. On the basis of the logging and pXRF results, a total of 578 one-metre intervals, representing 32.5% of the total drilling, were sampled and have been submitted to Intertek for four-acid digest multielement and gold by fire assay analysis. Assay results are expected to be received by midNovember.

Following receipt and interpretation of the drill assay results, the Company will plan its next stage of exploration at Oaky Creek and more broadly across the Armidale Antimony-Gold Project.

Oaky Creek represents a significant 3km long orogenic antimony system with multiple drill ready targets

The Oaky Creek prospect features quartz-carbonate-stibnite veins and breccias hosted within a tightly folded and faulted sequence of metamorphosed Carboniferous mudstone, siltstone and fine sandstone. The mineralisation has been targeted by two groups of shallow historical pits and shafts at Oaky Creek North and Oaky Creek South.

The Company's initial sampling program at Oaky Creek comprised a 50m x 100m spaced grid soil sampling program centered on a major splay of the Namoi Fault, accompanied by rock chip sampling. As initially reported in June 2025, the soil sampling defines a coherent, ~1.5km long, 100-200m wide, NNW-trending >2ppm Sb in soil anomaly extending both north and south of the historical workings at Oaky Creek North and a similarly-oriented ~1km long >2ppm Sb in soil anomaly extending north from the Oaky Creek South workings.

Sampling campaigns at Oaky Creek, returned multiple rock chip samples with values of over 25% Sb and 0.1g.t Au for five different areas, with mineralised and anomalous rock samples showing a strong spatial correlation to the antimony soil anomaly (Figure 1*). When considered collectively, the soil and rock chip results indicate a significant orogenic antimony mineral system with a strike extent of 3km, which is analogous to Larvotto Resources' (ASX:LRV) Market Cap. ~AU$620 million) Hillgrove Project, which lies east ofRed Mountain's project area.

Red Mountain's ~1300 sample infill hand auger soil sampling campaign across the full ~3km strike extent of the Oaky Creek prospect was completed across the late 2025 and early 2026 to tighten the Company's existing 100m x 50m spaced soil grid in order to better constrain individual drill targets. This detailed systematic work allowed the company to define five high priority orogenic antimony targets for drill testing at Oaky Creek (Figure 1*), four of which wereinitially drilled during the current maiden drilling program.

In July 2026, Red Mountain also reported the results of a trial, four line dipole-dipole induced polarisation (DDIP) survey over Oaky Creek South. Modelling of the data revealed a coherent NNESSW-striking, steeply SE-dipping chargeability anomaly that extends beneath and at least 300m southwest from outcropping quartz-carbonate-stibnite veins and shallow historical antimony workings at the Oaky Creek South Workings (Figure 1*). The anomaly shows a peak observed chargeability of over 7.2 mV/V, compared to background values that typically range from 2 to 3 mV/V. The anomaly significantly increases the size of the Oaky Creek South Workings target and is modelled to extend fromsurface to a depth of at least 200m, and over a strike extent of at least 400m, compared to the ~120m strike of surface vein mineralisation. It strengthens to the SSW and remains open in that direction.

Red Mountain Armidale Antimony-Gold Projectbackground

Red Mountain's 100%-owned Armidale Antimony-Gold Project lies in the Southern New England Orogen (SNEO) in northeastern New South Wales, approximately west of Australia's largest known antimony deposit, Larvotto's (ASX:LRV) Hillgrovedeposit, which is also the 8th largest antimony deposit globally. The SNEO is recognised as Australia's premier Antimony province (Figure 2*).

Red Mountain's Armidale Antimony-Gold Project has an extensive 85km length along the western side of the Peel Fault. The geology of the project area is dominated by isoclinally folded Carboniferous metasediments of the Tamworth Belt, which is a forearc basinal package related to west-dipping subduction of oceanic crust beneath the Lachlan Orogen. Ultramafic melanges of the Great Serpentinite Belt, which outcrop along the Peel Fault, are considered to be remnants of this oceanic crust. The Peel Fault System has recognised world-class mineral potential, with over 400 known orogenic gold and base metal mineral occurrences along its over 400km strike extent, but is underexplored, with less than 200 mostly shallow drillholes over its length, the majority of which are focused on discrete prospects. Oaky Creek is the company's highest priority andmost advanced prospect within the project and is one of several known orogenic gold and antimony mineral occurrences within the tenement (Figure 3*).

*To view tables and figures, please visit:
https://abnnewswire.net/lnk/IB08SZCO

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