• Red Mountain Mining (ASX:RMX) has spent the past year refining targets at its Oaky Creek prospect, where surface exploration has outlined an antimony system extending for around 3km.
• The company has now started its maiden 17-hole reverse circulation drilling program, targeting soil anomalies, historical workings and antimony-bearing veins, with assays expected early next quarter.
• Previous exploration returned rock chip results of up to 39.3% antimony and 1.09ppm gold, but the current program is the first drilling test and therefore represents an important step toward determining whether the surface mineralisation continues below ground.
• For investors, the key question is whether drilling can convert encouraging surface indicators into meaningful subsurface mineralisation, while results from Red Mountain's separate Pioneer Tungsten Project in Montana provide another near-term exploration catalyst.
Red Mountain Mining has started its maiden reverse circulation drilling program at the Armidale Antimony-Gold Project in New South Wales, moving its most advanced prospect from surface exploration into its first subsurface test.
The company plans to drill 17 holes over approximately three weeks at Oaky Creek, targeting areas identified through rock chip, conventional soil and auger soil sampling conducted over the past 12 months. Assay results are expected early next quarter.
The program follows a substantial amount of target definition work. Red Mountain completed roughly 1,300 infill hand-auger samples across the approximately 3km Oaky Creek trend in late 2025 and early 2026, helping it identify five high-priority antimony targets for drilling.
Among the areas being tested is the Oaky Creek South Main Grid, where the company has defined a coherent 300m by 30m antimony-arsenic auger soil anomaly. Previous rock chip sampling in the area returned results of up to 39.3% antimony and 1.09ppm gold.
Drilling will also target historical workings and exposed quartz-carbonate-stibnite veins at Oaky Creek North, alongside an antimony-bearing creek exposure further north.
The significance of the program is less about the number of holes and more about what Red Mountain is attempting to establish beneath the surface.
Previous soil sampling identified an approximately 1.5km-long antimony anomaly around Oaky Creek North and another roughly 1km-long anomaly extending north from the Oaky Creek South workings. Multiple rock chip samples from five areas have returned values above 25% antimony and 0.1g/t gold, with mineralised samples showing a spatial relationship to the soil anomalies.
Taken together, Red Mountain interprets the surface results as evidence of an orogenic antimony system extending for around 3km.
Geophysics has added another layer to the targeting.
A dipole-dipole induced polarisation survey completed over Oaky Creek South identified a chargeability anomaly extending beneath and at least 300m southwest from exposed veins and historical workings. The modelled anomaly extends from surface to at least 200m depth and across at least 400m of strike, compared with approximately 120m of mapped surface vein mineralisation. It also remains open toward the south-southwest.
The drilling program should provide the first direct test of whether these geochemical and geophysical signals correspond to meaningful antimony-gold mineralisation at depth.
For an early-stage explorer such as Red Mountain, encouraging surface grades alone do not establish the scale, continuity or economic potential of a mineral system.
That makes this drilling program a potentially important inflection point in the exploration process.
If drilling encounters mineralisation consistent with the surface anomalies, it could strengthen the geological interpretation of Oaky Creek and provide Red Mountain with information needed to plan follow-up drilling. Results across multiple targets would be particularly relevant when assessing whether mineralisation extends along a meaningful portion of the broader 3km trend.
The reverse is also true. Surface rock-chip grades can be highly localised, and geochemical or geophysical anomalies do not guarantee economically significant mineralisation underground. The maiden program therefore remains an exploration test rather than confirmation of a deposit.
Timing is another factor to watch. Red Mountain said drilling commenced later than indicated by its contractor due to rig availability, following prior wet-weather delays and other unforeseen circumstances. The company nevertheless expects the current program to take approximately three weeks.
Oaky Creek sits within Red Mountain's 100%-owned, 391km² Armidale Antimony-Gold Project in the Southern New England Orogen, an area the company describes as Australia's premier antimony province.
The project extends for around 85km along the western side of the Peel Fault. Red Mountain notes that more than 400 known orogenic gold and base-metal occurrences have been identified along the fault system's more than 400km strike extent, while historical drilling has been relatively limited.
The company also draws geological comparisons between Oaky Creek and Larvotto Resources' Hillgrove project, which lies east of Red Mountain's project area. That comparison provides regional context, but drilling will ultimately need to establish Oaky Creek's own scale and mineralisation characteristics.
Red Mountain is also building exposure to critical minerals outside Australia. Its US portfolio includes tungsten and antimony projects, with assay results from a comprehensive sampling program at the Pioneer Tungsten Project in Montana expected in early September.
That gives investors two near-term exploration readouts across different projects, although both remain dependent on assay results translating geological targets into evidence of mineralisation.
The immediate focus is likely to be completion of the 17-hole Oaky Creek program and the assay results expected early next quarter. Beyond headline grades, investors may want to watch the width and continuity of any mineralised intersections, whether drilling validates the soil and geophysical anomalies, and whether results justify a larger follow-up program.
Pioneer Tungsten assays expected in early September provide a separate near-term milestone. Together, these results could offer a clearer indication of whether Red Mountain's exploration portfolio is progressing from promising surface targets toward more substantive discoveries.
Red Mountain Mining Limited (ASX:RMX, OTCQB:RMXFF) is a critical minerals exploration and development company with projects in Australia and the United States. Its portfolio includes the Armidale Antimony-Gold Project in New South Wales and tungsten and antimony exploration projects in the US.
Have feedback on this article? Concerned about the content? Get in touch with us directly. Alternatively, email [email protected]
Simply Wall St analyst Andrew Legget and Simply Wall St have no position in any of the companies mentioned. This article is general in nature. We provide commentary based on historical data and analyst forecasts only using an unbiased methodology and our articles are not intended to be financial advice. It does not constitute a recommendation to buy or sell any stock and does not take account of your objectives, or your financial situation. We aim to bring you long-term focused analysis driven by fundamental data. Note that our analysis may not factor in the latest price-sensitive company announcements or qualitative material.