Red Mountain Mining Ltd (ASX:RMX) Drilling Approval Received and IP Sample Completed at Armidale

18 May 2025

Price Sensitive Announcement $

Highlights:

• Red Mountain has received NSW Resources Regulator approval for a reverse circulation drilling program at Oaky Creek of up to 32 holes to a maximum depth of 300m. The approved program targets priority drill targets generated from the Company’s extensive surface geochemical sampling program at the Armidale Antimony-Gold Project in New South Wales
• The Company anticipates that the drilling program will commence at the end of this quarter.
• Red Mountain is also expecting the results of an orientation Induced Polarisation (IP) survey across surface mineralisation at Oaky Creek South, using both Gradient Array and DipoleDipole techniques. The survey was completed by Fender Geophysics to test the efficacy of the two IP methods in detecting alteration and Antimony mineralised structures and mapping them subsurface
• The results of the IP survey will be used to assist in targeting drillholes to test potential deeper mineralisation at Oaky Creek South. Subject to results, Red Mountain will also consider completing a more comprehensive IP survey over the entire Oaky Creek prospect that could potentially map out further Antimony mineralisation that does not have a surface geochemical expression
• Conventional and auger soil sampling and rock chip analytical results of up to 39.3% Sb and 1.09ppm Au for Oaky Creek indicate the presence of 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 (See ASX Announcement: 2 October 2025)
• RMX is well funded to complete planned US and Australian exploration activity at its Critical Minerals Projects, following a recent successful raising and execution of a Stand-by-Facility (subject to shareholder approval) which will provide ~$4m in total funding capacity
• Red Mountain is finalising Due Diligence at the Pioneer Tungsten Project in Montana and expects to report on the final outcome by the end of this month

Overview:

Red Mountain Mining Limited 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 that it has received approval from the NSW Resources Regulator for a 32 hole reverse circulation (RC) drilling program with a maximum hole depth of 300m at the Oaky Creek Antimony prospect at the Company’s 100% owned Armidale Antimony-Gold project in the Southern New England Orogen of New South Wales. The Company is finalising scheduling details prior to planned commencement of drilling at the end of this quarter.

The approved RC drilling program is designed to test a series of compelling 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). The program will drill test the
coherent 300m x 30m Oaky Creek South Main Grid antimony-arsenic auger soil anomaly, which has
also returned rock chip results of up to to 39.3% Sb & 1.09ppm Au; as well as the three targets
defined by rock chip and auger soil sampling at Oaky Creek North.

The approved drilling approval application does not limit Red Mountain to specific collar locations,
allowing the Company the flexibility to adjust drill locations in response to initial results, for example
to test for depth or strike extensions to early mineralised intercepts. Initial drillholes are planned to
be between 100m and 150m deep, significantly shallower than the maximum requested approved
hole depth of 300m, in order to establish continuity of mineralisation from surface. However the
maximum depth of 300m will allow for testing of further down-dip extensions of mineralisation, if
justified by early results. Orogenic antimony vein systems such as those present at Oaky Creek are
known to have significant depth extent, with Larvotto Resources’ (ASX: LRV; Market Cap ~$739
million) analogous Hillgrove deposit known to extend over vertical depths of more than 1km1

Red Mountain completes orientation Induced Polarisation survey

Red Mountain has observed with interest the use of Gradient Array Induced Polarisation (GAIP) at
Hillgrove by Larvotto Resources at Hillgrove over the past twelve months as a tool to identify
extensions to known orogenic antimony-gold mineralisation and as a targeting tool for previously
unrecognised parallel mineralised veins2, 3, 4, 5, 6, 7. Based on their ASX announcements, Larvotto’s GAIP
surveys appear to have detected subtle conductivity and resistivity variations associated with narrow
(~1m) vein-style mineralisation and the broader (up to 20m) silica-sericite alteration envelopes that
typically surround high grade veins.

Red Mountain has engaged Fender Geophysics, who completed the GAIP surveys at Hillgrove, to
undertake an orientation IP survey at Oaky Creek South. The survey was completed in the first half of
May and comprised three 1.6km long, 100m spaced, NW-SE oriented lines and a 1.5km long SW-NE
oriented cross line (Figure 2). Fender collected GAIP along all three NW-SE lines and Dipole-Dipole IP
(DDP) along all four lines. Generally speaking, DDP is more effective than GAIP at detecting both
resistivity and chargeability responses for steeply dipping narrow structures such as orogenic antimony
veins8. However, the longer recording times required for DDP means that the technique is significantly
more expensive, particularly for large surveys. Red Mountain is therefore trialing both techniques to
maximise the potential to directly detect mineralisation and to compare the effectiveness of DDP and
the less expensive GAIP technique, which would be more cost effective for a potential future survey
across the entire 3km strike extent of the Oaky Creek prospect.

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 10, 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 Creek1112, returned multiple rock chip samples13, 14, 15 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$739 million) Hillgrove
Project, which lies east of Red 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 past two quarters to tighten the
Company’s existing 100m x 50m spaced soil grid in order to better constrain individual high priority
drill targets. This detailed systematic work has allowed the company to define five high priority
orogenic antimony targets16 for drill testing at Oaky Creek (Figure 1).

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