Announcement PDF ASX: RMX investorhub.redmountainmining.com.au info@redmountainmining.com.au Red Mountain Mining Ltd ACN 119 568 106 OUTCROPPING GARNET SKARN IDENTIFIED AND MAGNETIC MODELLING HIGHLIGHTS SIGNIFICANT POTENTIAL AT PIONEER HIGHLIGHTS: • Red Mountain Mining has identified outcropping garnet skarn at the Mammoth and Greenstone prospects – two of the three areas that comprise the Company’s 100% owned Pioneer Tungsten Project in Montana, USA • The Pioneer Tungsten Project comprises three claim areas – Greenstone, Mammoth and Lost Creek – located along the eastern margin of the Mount Torrey Batholith, which locally features massive limestone-hosted garnet skarns, up to 25m thick. These local skarns are known to contain Tungsten (W) mineralisation as scheelite (CaWO4) • Red Mountain has submitted 24 rock chip samples, collected from Mammoth and Greenstone, for multielement analysis to confirm the presence of Tungsten mineralisation in garnet skarns that outcrop at surface within the Company’s claims • Analytical results from the initial sampling are anticipated to be received before the end of June • A magnetic modelling study reveals subsurface magnetic bodies beneath the Greenstone and Mammoth claims, interpreted to represent shallow extensions of the granodiorite source of the skarn mineralisation, indicating that Red Mountain’s claims also have clear geological potential for limestone-hosted Tungsten-bearing garnet skarn mineralisation at shallow depths beneath outcropping quartzite • Red Mountain’s Pioneer Tungsten Project claims encompass similar geology and lie adjacent to claims purchased in November 2025 by Almonty Industries (Market Cap AU$6.6 billion), hosting the Gentung Tungsten Deposit, with a mineral resource of 6.83Mt @ 0.315% WO3; as well as the Ivanhoe and Lost Creek Mines, which are estimated to have collectively produced 680kt of Tungsten ore in the 1950s and 1970s • Further reconnaissance mapping and surface sampling is planned for June, with the Company expecting to be able to move rapidly to drill testing of downdip extensions of skarn mineralisation at one or more prospects, subject to positive analytical results ASX Announcement 9 June 2026 RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 2 Red Mountain Mining Limited (ASX: RMX, US OTCQB: RMXFF, or “the Company”), 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 the Company’s US field team has identified and sampled outcropping garnet skarn at the Mammoth and Greenstone prospects – two of the three areas that comprise the Company’s 100% owned Pioneer Tungsten Project in Montana, USA. The Pioneer Tungsten Project comprises three groups of claims - the Greenstone, Mammoth and Lost Creek prospects - along the eastern margin of the Mount Torrey Batholith (Figure 1), all with documented tungsten-bearing garnet skarn mineralisation1 . Massive garnet skarns, up to 25m thick2 are known to occur in adjacent ground. These skarns contain Tungsten (W) mineralisation as scheelite (CaWO4), locally assaying over 0.5% WO3 2 . In addition to the exposures of garnet skarn at surface, Red Mountain’s claims also have clear geological potential for limestone-hosted tungsten-bearing garnet skarn mineralisation at shallow depths beneath overlying quartzite units, where magnetic modelling undertaken by Arrow Geosciences, indicates subsurface magnetic bodies, interpreted to represent the granodiorite source of the skarn mineralisation. Reconnaissance mapping confirms garnet skarns at Mammoth and Greenstone During late May, as part of Red Mountain’s due diligence process, the Company’s US field crew completed a three-day reconnaissance field visit to the Mammoth and Greenstone project areas. During the visit, the team were able to visually confirm the presence of outcropping garnet skarn at both Mammoth and Greenstone (Figure 2) and collected 24 rock chip samples of skarn and other altered material (Figure 3, Figure 4, Appendix 1), which have been submitted for multielement analysis, with results expected before the end of June. The primary goal of this reconnaissance sampling is to measure the tungsten content of the skarn samples to provide a first-pass indication of the potential of Red Mountain’s claims to host economically significant garnet skarn hosted tungsten mineralisation, similar to the estimated 680kt of tungsten ore that was mined at Ivanhoe and Lost Creek in the 1950s 1 Pattee, E.C., 1960. U.S. Bureau of Mines, Report of Investigation 5552. https://digital.library.unt.edu/ark:/67531/metadc38682/m2/1/high_res_d/metadc38682.pdf 2 Nelson et al., 2012. https://almonty.com/wp-content/uploads/2025/11/Lentung-43-101.pdf RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 3 and 1970s3 and the mineralisation that comprises Almonty’s Gentung tungsten deposit, which has an estimated mineral resource of 6.83Mt @ 0.315% WO3 3 . Figure 1: Surface geology of the eastern margin of the Pioneer Batholith in Montana, showing the location of Red Mountain’s Mammoth, Lost Creek & Greenstone claim areas, Almonty Industry’s claims, the Ivanhoe, Lost Creek and Greenstone mines, and published USGS tungsten occurrences. Geology after McDonald and Yakovlev (2019)4 , Zen (1988)5 & McDonald et al. (2012)6 . 3 Nelson et al., 2012. https://almonty.com/wp-content/uploads/2025/11/Lentung-43-101.pdf 4 https://ngmdb.usgs.gov/Prodesc/proddesc_108777.htm 5 https://ngmdb.usgs.gov/Prodesc/proddesc_21817.htm 6 https://ngmdb.usgs.gov/Prodesc/proddesc_97585.htm RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 4 Figure 2: (A) Strongly weathered skarn layers with intermixed clinopyroxene and garnets close to the Mammoth Adit. Samples 732288-732291 were collected here. (Photo taken looking west - 355686mE 5043604mN; refer to Figure 3). (B) Sample location 663911: Pale green to green skarn with <0.5 % garnet stringers up to 2mm thick in wall of 1951 Cut#9, immediately above historical drill holes WDH3 and WDH4 (Photo taken looking west - 358709mE 5030088mN; refer to Figure 4). RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 5 Figure 3: Surface geology over topography of Red Mountain’s Mammoth claims area, showing Red Mountain rock chip sample locations relative to the location of the Company’s claim area; Almonty’s claims; and the Ivanhoe mine claim. The locations of the Mammoth Adit, the photograph shown in Figure 2A and the surface projection of Almonty’s 6.83Mt @ 0.315% WO3 Gentung mineral resource7 are also highlighted. Sample coordinates and field descriptions are provided in Appendix 1. Figure 4: Surface geology over topography of Red Mountain’s Greenstone claims area, showing Red Mountain rock chip sample locations relative to the location of the Company’s claim area; and the Greenstone mine claim. The locations of outcropping garnet skarn in the Greenstone area (after Pattee, 19608 ) and the photograph shown in Figure 2B are also highlighted. Sample coordinates and field descriptions are provided in Appendix 1. 7 Nelson et al., 2012. https://almonty.com/wp-content/uploads/2025/11/Lentung-43-101.pdf 8 Pattee, E.C., 1960. U.S. Bureau of Mines, Report of Investigation 5552. https://digital.library.unt.edu/ark:/67531/metadc38682/m2/1/high_res_d/metadc38682.pdf RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 6 Magnetic modelling indicates shallow granodiorite beneath Mammoth and Greenstone Magnetic data from the 2023 USGS Butte extension of the airborne magnetic and radiometric survey of the Boulder Batholith region of Montana9 clearly show a strong magnetic response from the Uphill Creek Granodiorite, while the Grayling Lake Granite and the metasedimentary host rocks for the Mount Torrey Batholith are non-magnetic (Figure 5). Figure 5: First vertical derivative USGS magnetic imagery relative to the mapped extents of the Uphill Creek Granodiorite and Grayling Lake Granite over Red Mountain’s (A) Mammoth, (B) Greenstone and (C) Lost Creek claim areas. The images clearly show the strong magnetic response from the Uphill Creek Granodiorite and the muted response from the Grayling Lake Granite and metasedimentary host rocks for the Mount Torrey Batholith. at all three prospects. The Gentung tungsten resource lies at ~200m depth on the contact between Snowcrest Range Group limestone and the Granodiorite. As can be seen on (A), the shallow subsurface extension of the Granodiorite beneath Gentung is expressed as a magnetic high. Similar magnetic features extend well beyond the surface margin of the Granodiorite beneath Red Mountain’s Mammoth and Greenstone claims, suggesting similar subsurface extensions with potential to form skarn mineralisation. In contrast, the margin of the Granodiorite at Lost Creek appears to generally dip very steeply from surface. 9 Anderson et al., 2025. https://www.sciencebase.gov/catalog/item/63a10b4ad34e0de3a1f2796d RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 7 The strong magnetic contrast allows the margin of the Uphill Creek Granodiorite, which is the source of fluids for the tungsten-bearing garnet skarn mineralisation in the district, to be mapped subsurface using magnetic data. As can be seen on Figure 5A, the 6.83Mt Gentung tungsten mineral resource, which lies at a depth of ~200m on a near flat-lying contact between Snowcrest Range Group limestone and the Granodiorite10 , is expressed as a magnetic high, which effectively maps the relatively shallow subsurface extension of the Granodiorite. Similar magnetic features extend well beyond the surface margin of the Granodiorite beneath Red Mountain’s Mammoth (Figure 5A) and Greenstone (Figure 5B) claims, suggesting similar subsurface extensions with potential to form skarn mineralisation. In contrast, the margin of the Granodiorite at Lost Creek (Figure 5C) appears to generally dip very steeply from surface. To better understand the geometry of the Uphill Creek Granodiorite, Red Mountain engaged Arrow Geosciences to produce a 3D model of magnetic susceptibility from the USGS magnetic dataset over the Company’s three claim areas. To correct for the magnetics of the Granodiorite, Arrow completed its inversion using the Virtual Resultant Magnetisation Intensity (VRMI). The data were inverted using 25m3 cells, with topographic control provided by the globally available Shuttle Radar Topography Mission (SRTM) dataset, which has a spatial resolution of ~30m. The results of the magnetic modelling are summarised in Figure 6. The results confirm Red Mountain’s initial interpretation of the USGS magnetic data and show a ridge of magnetic material, interpreted to be a subsurface extension of the Uphill Creek Granodiorite, associated with the Gentung tungsten resource, where resource definition drilling has confirmed its presence at a depth of ~200m10 . Similar subsurface magnetic features lie at drillable depths beneath Red Mountain’s Mammoth and Greenstone Claim areas, with the latter area showing a spatial relationship between the magnetic high and mapped garnet skarn at surface. In contrast, the modelled magnetic edge of the Granodiorite at Lost Creek is very steeply dipping. The magnetic model at Mammoth also shows a central “hole”, which is interpreted to correspond to the intrusion of the later non-magnetic Grayling Lake Granite into the Uphill Creek Granodiorite. 10 Nelson et al., 2012. https://almonty.com/wp-content/uploads/2025/11/Lentung-43-101.pdf RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 8 Figure 6: 3D perspective views looking approximately northwest of the results of Arrow Geoscience magnetic modelling at Mammoth, Greenstone and Lost Creek. Each image shows Red Mountain’s claims as white outlines draped over topography (which is partially transparent) and shows 3D isosurfaces for modelled magnetic susceptibility from 1000 x 10-5 SI (red) to 300 x 10-5 SI (shallowest cyan surface). Vertical extent for all models is 1km, no vertical exaggeration. Further surface sampling planned prior to targeted drilling Red Mountain will undertake additional surface geological mapping and sampling across all three claim areas of the Pioneer Tungsten Project during June and, as noted above, expects to receive multielement analytical results for the 24 samples already collected before the end of this month. Subject to receiving positive surface analytical results for tungsten, the Company anticipates that it will be in a position to rapidly define drill targets to test for subsurface extensions of outcropping skarn mineralisation at one or more targets during the current northern hemisphere summer and plans to move as rapidly as possible to secure the necessary environment and regulatory approvals with the goal of executing any planned drilling program as expeditiously as is possible. RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 9 Pioneer Project geology The Pioneer Tungsten Project claims cover three discrete locations, the Greenstone, Mammoth and Lost Creek prospects, where the eastern margin of the Uphill Creek Granodiorite is in direct contact at surface with the Snowcrest Range Group (Figure 1). Red Mountain’s claims encompass Tungsten- bearing skarn mineralisation mapped and sampled in the middle of last century and a number of historical workings still visible today. The claims also lie immediately adjacent to claims purchased in November 202511 by Almonty Industries (NASDAQ: ALM / TSX: AII / ASX: AII / Frankfurt: ALI1; Market Cap AU$6.6 billion), which include the Gentung Tungsten Deposit, which has a total mineral resource of 6.83 Mt @ 0.315 % WO3 12 ; as well as the Ivanhoe and Lost Creek Mines, which are estimated to have collectively produced 680kt of tungsten ore in the 1950s and from 1970 to 197512 . The Torrey Batholith is a large volume composite complex that forms the core of the Pioneer Mountains in southwest Montana. The batholith ranges in composition from gabbro to granite, but is dominantly granodioritic in composition. Tungsten mineralisation occurs along the entire eastern contact of the Pioneer Batholith where it is in contact with mid-Paleozoic carbonate-rich sedimentary rocks (Figure 1), but to date significant mineralisation, occurring in scheelite-bearing massive garnet skarns, has only been found where the limestones of the Snowcrest Range Group contact the Uphill Creek Granodiorite. Significantly, there does not appear to be any skarn development or tungsten mineralisation associated with the Grayling Lake Granite, which cuts and is therefore younger than the granodiorite and associated skarn mineralisation at the Mammoth Prospect. Historical tungsten production The earliest recorded interest in the garnet skarn hosted tungsten mineralisation surrounding the Mount Torrey Batholith dates from the early 1950s, driven by the US Federal Government’s strategic metal stockpiling program, with significant production recorded from the Ivanhoe and Lost Creek mines (Figure 1). Exploration for tungsten was carried out between 1951 and 1953 around the Ivanhoe Mine (also known as the Brown’s Lake Mine), which had been mined for copper, silver and gold in 1928 and 1929, recording production of 5.7t Cu; 647 oz Ag and 1 oz Au13 . Open pit tungsten 11 ALM press release 17/11/2025. https://press.almonty.com/almonty-advances-intent-to-become-the-leading-u-s-integrated-tungsten-producer-with-acquisition-of-gentung-browns- lake-tungsten-project-in-montana/ 12 Nelson et al., 2012. https://almonty.com/wp-content/uploads/2025/11/Lentung-43-101.pdf 13 Geach, R.D., 1972. Montana: Montana Bureau of Mines and Geology Bulletin 85. https://www.mbmg.mtech.edu/mbmgcat/public/ListCitation.asp?pub_id=10086&#gsc.tab=0 RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 10 production from the Ivanhoe Mine commenced in October 1953 and initially ceased in 1957, with total production during this period of 567kt at an average grade of 0.35% WO3 14 . Similar skarn-hosted tungsten mineralisation was mined by the Minerals Engineering Company between 1952 and 1956 from a series of adits and small open pits at the Lost Creek Mine, ~5km southeast of Ivanhoe. The total recorded production from Lost Creek during this period is 19kt at an average grade of 0.18% WO3 8 . Both mines remained idle until 1971, when General Electric purchased the properties and rebuilt the mill at Ivanhoe, which operated until 1975. Minor Tungsten production is also recorded from the Greenstone Mine during the 1950s, with recorded production of 900kg of sorted ore, containing 1.2% WO3 14 . It is estimated that total production from the district from the 1950s and 1970s is approximately 680kt of tungsten ore15 . Authorised for and on behalf of the Board, Mauro Piccini Company Secretary Disclaimer In relying on the above mentioned ASX announcement and pursuant to ASX Listing Rule 5.23.2, the Company confirms that it is not aware of any new information or data that materially affects the information included in the above-mentioned announcement. Forward–Looking Statements Some of the statements appearing in this announcement may be in the nature of forward-looking statements. You should be aware that such statements are only predictions and are subject to inherent risks and uncertainties. Those risks and uncertainties include factors and risks specific to the industries in which Red Mountain operates and proposes to operate as well as general economic conditions, prevailing exchange rates and interest rates and conditions in the financial markets, among other things. Actual events or results may differ materially from the events or results expressed or implied in any forward- looking statement. No forward-looking statement is a guarantee or representation as to future performance or any other future matters, which will be influenced by a number of factors and subject to various uncertainties and contingencies, many of which will be outside Red Mountain’s control. 14 Pattee, E.C., 1960. U.S. Bureau of Mines, Report of Investigation 5552. https://digital.library.unt.edu/ark:/67531/metadc38682/m2/1/high_res_d/metadc38682.pdf 15 Nelson et al., 2012. NI 43-101 Technical Report of the Lentung (Gentung) Tungsten & Garnet Deposit https://almonty.com/wp-content/uploads/2025/11/Lentung-43-101.pdf RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 11 Competent Person Statement The information in this announcement that relates to Exploration Results and other technical information complies with the 2012 Edition of the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code). It has been compiled and assessed under the supervision of contract geologist Mark Mitchell. Mr Mitchell is a Member of the Australasian Institute of Geoscientists and has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the JORC Code. Mr Mitchell consents to the inclusion in this announcement of the matters based on his information in the form and context in which it appears. About Red Mountain Mining Red Mountain Mining Ltd (ASX: RMX, US CODE: RMXFF) is a Critical Minerals exploration and development company focussed on accelerating development at its United States and Australia based Projects, located in Tier-1 Mining Districts. Red Mountain is fast-tracking its Critical Minerals projects in the US and Australia, and the Board and Management is determined to rapidly define a portfolio of advanced projects to assist the United States and other Western countries with a reliable, high-quality source of commodity supply, including from the Company’s Armidale Antimony-Gold Project located in NSW, Australia, which has delivered multiple high-grade antimony rock chip samples to date (up to 39.3% Sb); and its US Critical Minerals Portfolio. comprising the Pioneer Tungsten Project in Montana, which encompasses the same geology and exhibits the same skarn-style mineralisation as the 6.8Mt Gentung tungsten resource (owned by NASDAQ: ALM); the Utah Antimony Project in the highly prospective Antimony Mining District of Utah, adjacent to the Antimony Canyon Project (owned by ASX: AT4); the Thompson Falls Antimony Project with initial assay results of up to 36.5% Sb at historical mines located near the NYSE: UAMY Antimony Smelter, and two Idaho Antimony Projects. JOIN THE RED MOUNTAIN MINING INVESTOR HUB Visit https://investorhub.redmountainmining.com.au for access to the Investor Hub RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 12 Appendix 1 NAD83 UTM 12 coordinates and field descriptions of rock chip samples collected from the Mammoth and Greenstone claim areas. As WO3 grades are expected to be <1%, no attempt has been made to visually identify scheelite (CaWO4) or estimate tungsten content for any of the samples. The identification of skarn mineralogy (garnet and pyroxene) does not imply that Tungsten will be present in any sample. mE mN 663911 Greenstone 358709 5030088 Sample taken from probable 1951 bulk sample location taken from historical trench wall. Pale green to green skarn with <0.5 % garnet stringers up to 2mm thick. 663912 Greenstone 358712 5030117 Outcrop. Pale green garnet skarn. Quartz rich with <0.5% garnet veinlets up to 2mm thick. 663917 Greenstone 358692 5029901 Float. Moderately oxidized garnte skarn with ~0,5% garnet veinlets up to 1mm thick. Proximal to 1951 prospecting trenches. 663918 Greenstone 358686 5029845 Bleached and altered sandstone with ~5% semi-druzy stockwork quartz veinletsup to 5mm in width. 663919 Greenstone 358640 5029481 Waste pile from angled shaft still open to ~6m in depth. Granite with pervasive moderate chlorite alteration and ~5% pyroxene crystals up to to 2mm in size. 663920 Mammoth 355580 5043754 Test pit waste pile. Light mint green moderately argilized garnet skarn material. 663921 Mammoth 355616 5043586 Garnet skarn outcrop near the Mammoth Adit with poddy granualr quartz veins up to 5mm thick and ~2% brown pyroxene blebs and veinlets up to 1cmin size. 663922 Mammoth 355680 5043569 Skarn outcrop at entrance to a collapsed cave. Sample is dominated by malachite and manganese with minor chalcopyrite and rare bornite. 663923 Mammoth 355674 5043420 Outcrop of strongly oxidised and pervasive argillic altered granite. 663924 Mammoth 355682 5043363 Float sample of garnet skarn with pyroxene blebs up to 3cm in size. 732285 Greenstone 358706 5030094 Trench wall above 1951 drillholes WDH3 and WDH4. Garnet skarn with garnets up to 5mm in size. 732288 Mammoth 355692 5043609 Mammoth Adit outcrop, greenish gray skarn with ~2% 0.5-1mm garnet. 732289 Mammoth 355691 5043607 Mammoth Adit outcrop, greenish gray skarn with ~2% 0.5-1mm garnet. 732290 Mammoth 355683 5043603 Mammoth Adit outcrop, greenish gray skarn with ~2% 0.5-1mm garnet. 732291 Mammoth 355686 5043604 Mammoth Adit outcrop, greenish gray skarn with ~2% 0.5-1mm garnet. 732292 Mammoth 355680 5043572 Calc-silicate skarn or hornfels with traces of epidote. 732293 Mammoth 355680 5043572 Light mint green moderately argilized garnet skarn material. 732294 Mammoth 355676 5043427 Outcrop of strongly oxidised and pervasive argillic altered granite. 732295 Greenstone 358710 5029911 Float close to 1951 Cut #8. Moderately oxidised skarn with ~1-2% garnet veinlets up to 5mm in thickness. Proximal to historical prospecting trenches. 732296 Greenstone 358718 5030073 Pale green to green skarn (?) with <0.5% garnet stringers up to 1mm thick. 732297 Greenstone 358727 5030074 Dark greenish-gray, fine-medium grained calc silicate, with proxene blebsup to 1cm in size. 732298 Greenstone 358743 5030056 Float near 1951 Cut#8 road. Moderately oxidised skarn with garnet veinlets up to 2mm thick. Proximal to historical prospecting trenches. 732299 Greenstone 358770 5030047 Float near 1951 Cut#8 road. Moderately oxidised skarn with garnet veinlets up to 2mm thick. Proximal to historical prospecting trenches. 732300 Greenstone 358755 5030046 Float near 1951 Cut#8 road. Moderately oxidised skarn with garnet veinlets up to 2mm thick. Proximal to historical prospecting trenches. Sample Number Prospect NAD83 UTM Zone 12 Field Description RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 13 JORC Code, 2012 Edition - Table 1 1.1 Section 1 Sampling Techniques and Data Criteria JORC Code explanation Commentary Sampling techniques • Nature and quality of sampling (e.g. cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. • Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. • Aspects of the determination of mineralisation that are Material to the Public Report. • In cases where ‘industry standard’ work has been done this would be relatively simple (eg ‘reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay’). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information. • Representative surface rock chip samples collected by hand from insitu outcrop, waste piles from historical workings and float; as described in Appendix 1. Drilling techniques • Drill type (e.g. core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (e.g. core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc). • No drilling results are reported. RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 14 Criteria JORC Code explanation Commentary Drill sample recovery • Method of recording and assessing core and chip sample recoveries and results assessed. • Measures taken to maximise sample recovery and ensure representative nature of the samples. • Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material. • No drilling results are reported. Logging • Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource estimation, mining studies and metallurgical studies. • Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. • The total length and percentage of the relevant intersections logged. • No drilling results are reported. • Visual field descriptions of rock chip samples made by a qualified experienced geologist are provided in Appendix 1. Sub- sampling techniques and sample preparation • If core, whether cut or sawn and whether quarter, half or all core taken. • If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. • For all sample types, the nature, quality and appropriateness of the sample preparation technique. • Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. • Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. • Whether sample sizes are appropriate to the grain size of the material being • Outcrop rock chip samples are collected as representative of the sampled geological unit. • Float and waste dump samples are not representative of overall geology but are collected as potential indicators to nearby insitu material of unknown location and scale. • The surface sampling is reconnaissance in nature and designed to be indicative rather than fully quantitative. No duplicate samples were collected for analysis. RED MOUNTAIN MINING LTD ASX: RMX INVESTORHUB.REDMOUNTAINMINING.COM.AU 15 Criteria JORC Code explanation Commentary sampled. Quality of assay data and laboratory tests • The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total. • For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. • Nature of quality control procedures adopted (e.g. standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been established. • No assay results are reported. USGS Data Sets Used • The 2023 USGS Butte extension of the airborne magnetic and radiometric survey of the Boulder Batholith region of Montana was flown by helicopter on 200m spaced East-West lines at a nominal terrain clearance of 100m, with North-South oriented control lines spaced at 2000m. • All survey data, metadata and relevant contractor reports are available for download using THIS LINK • Surface geology was mapped by the US Geological Survey Co-operative Geological Mapping programme released in 2020 (GeMS) under the geological Map Schema. Verification of sampling and assaying • The verification of significant intersections by either independent or alternative company personnel. • The use of twinned holes. • Documentation of primary data, data entry procedures, data verificat