Red Mountain Mining Ltd (ASX: RMX) — IP Extends Antimony Target Strike at Oaky Creek South; Drill Testing to Commence in Two Weeks

9 July 2026

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Highlights:

• 2D and 3D modelling of dipole-dipole induced polarisation (DDIP) data from Oaky Creek South has revealed a coherent NNE-SSW-striking, steeply SE-dipping chargeability anomaly extending beneath and southwest from outcropping quartz-carbonate-stibnite veins and shallow historical workings
• The anomaly shows a peak observed chargeability of over 7.2mV/V against background values of 2–3mV/V, modelled to extend over a strike extent of at least 400m — more than three times the ~120m surface footprint of outcropping veins at Oaky Creek South — with a vertical extent of over 100m and remaining open to the SSW
• Maiden RC drilling program to commence the week of 20 July 2026, with Durock Drilling contracted to complete up to 32 RC holes to a maximum depth of 300m across four of five priority targets at Oaky Creek
• The approved program provides flexibility to adjust drill locations in response to initial results, with initial holes planned at 100–150m depth to establish near-surface continuity, and maximum approved depth of 300m available for testing down-dip extensions
• Drilling is expected to be completed before end of August, with assay results anticipated this quarter
• Oaky Creek hosts rock chip results of up to 39.3% Sb and 1.09ppm Au across a ~3km orogenic antimony-gold corridor, analogous to Larvotto Resources’ (ASX: LRV) Hillgrove Project — Australia’s largest known antimony deposit

Overview:

Red Mountain Mining has delivered a significant pre-drill update from its Oaky Creek South antimony prospect, with 2D and 3D modelling of recently completed dipole-dipole induced polarisation (DDIP) survey data revealing a coherent chargeability anomaly that materially extends the known size of the Oaky Creek South drill target — and the maiden RC drilling program is now just two weeks away.

The DDIP survey comprised four lines across Oaky Creek South totalling 6.2 line-km, designed to test the subsurface electrical response across the Oaky Creek South Main Grid soil anomaly, the historical surface workings and vein mineralisation, and a major splay of the Namoi Fault interpreted as a potential feeder structure for the orogenic antimony system. Modelling of the chargeability data has returned a striking result: a strong, coherent anomaly with a peak chargeability of 7.2mV/V — more than double the 2–3mV/V background — that is most strongly developed at the Oaky Creek South Workings and extends for at least 400m along strike to the SSW, well beyond the ~120m surface expression of the outcropping vein mineralisation. The anomaly is interpreted to represent chargeable sulphide within steeply dipping quartz-carbonate-stibnite veins persisting to depths exceeding 100m, and potentially much deeper — significantly increasing the scale of the drill target.

With the NSW Resources Regulator having already granted full approval for the 32-hole, up to 300m deep RC program, and Durock Drilling contracted with a start date of 20 July 2026, Red Mountain is now in the final stages of pre-drill preparation. The program will test four of the five high-priority orogenic antimony targets defined from the Company’s extensive surface geochemical program — including the Oaky Creek South Main Grid, the Oaky Creek South Workings and the newly defined chargeability anomaly extending to the SSW, the Oaky Creek North Workings and the Sb-bearing Creek exposure. A fifth target, the Oaky Creek North South Extension, remains temporarily inaccessible due to crop cover.

Initial holes will be drilled to 100–150m to establish near-surface continuity before testing deeper extensions justified by early results — a sensible sequencing approach given orogenic antimony vein systems of this type are known to have significant depth extent, with the analogous Hillgrove deposit extending to over 1km vertical depth.

With drilling commencing imminently and assay results expected this quarter, Red Mountain is entering what is likely to be its most newsworthy period to date at the Armidale Antimony-Gold Project.

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. The Company’s flagship Armidale Antimony-Gold Project spans an 85km corridor in the Southern New England Orogen of New South Wales — Australia’s premier antimony province — sitting in close proximity to Larvotto Resources’ Hillgrove deposit, Australia’s largest known antimony deposit and the 8th largest globally. Oaky Creek is the Company’s highest priority prospect within the project, with a ~3km orogenic antimony-gold corridor defined by extensive surface geochemical work and maiden RC drilling now imminent. In the United States, Red Mountain holds the Pioneer Tungsten Project in Montana, adjacent to Almonty Industries’ Gentung Tungsten Deposit.

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