2025 Summer Exploration Programme & Placing

GREAT WESTERN MINING CORPORATION PLC

("Great Western", "GWM" or the "Company")

2025 SUMMER EXPLORATION PROGRAMME &

PLACING

Great Western Mining Corporation PLC (AIM - GWMO, Euronext Growth - 8GW), which is exploring multiple precious and critical mineral prospects in the Walker Lane Trend of Nevada, USA, announces the successful completion of a placing to raise £1.25 million before expenses and provides an update on its near-term exploration plans for enhancing the value of its portfolio.

HIGHLIGHTS

PLACING OF NEW SHARES

· Placing of 125 million new ordinary shares of €0.0001 par value in the capital of the Company at 1p (the 'Placing Shares') to raise £1,250,000.

· Grant of Fundraise Warrants for all subscribers of New Ordinary Shares in the Fundraising at 1.3 p per share on a 1 for 2 basis, subject to approval of an increase in the authorised share capital.

· Shard Capital Partners appointed as joint broker to the Company.

USE OF FUNDS

· Drilling planned at West Huntoon copper porphyry prospect to verify surface indications and help secure partners for accelerated development.

· Geophysical survey and first drilling planned at Rhyolite Dome gold prospect (Olympic Gold Project).

· Ongoing work at Defender & Pine Crow prospects to establish further potential of tungsten workings.

· Larger mining companies actively sought for participation in Eastside Mine/Tango copper porphyry prospect.

· Management of claims portfolio including adding and relinquishing acreage to focus on most prospective areas.

· Team strengthened, adding significant experience and industry knowhow.

Great Western Chairman Brian Hall commented: "We are very pleased to have secured the funds to move forward positively this summer with an accelerated exploration programme, which will include drilling for copper at the West Huntoon porphyry prospect and gold at Rhyolite Dome on the Olympic Gold claims, following a period of detailed and constructive geological work. We will also be focusing on our tungsten prospects and expect to be able to announce results of recent field work in the near future."

WEST HUNTOON COPPER PORPHYRY PROSPECT

The Company's West Huntoon copper prospect bears all the signs of a porphyry setting, as confirmed by a third-party expert report commissioned in 2024. Three km² of soil sampling in the hills to the West of the Huntoon Valley around a hosting granite intrusion has yielded consistent copper readings up to the margin of tertiary cover over the floor of the Huntoon Valley, where copper indications are buried and no longer detectable at surface. A geophysical (IP) survey has been conducted over the prospect, showing a continuation of prospectivity under tertiary cover on the valley floor. In 2017, the Company drilled a single hole at West Huntoon which resulted in significant copper intercepts. Subsequently, intensive field work, together with the recent geophysical survey and improved modelling of the copper zone, has identified much stronger drill targets for copper as well as identifying very high-grade precious metal grab samples (up to 16.17 g/t Au and 2,438 g/t Ag). A new drill programme is now planned to test the results at depth.

In the hills on the NE side of the Huntoon Valley at the M2 prospect, an inferred copper resource of 4.28M tonnes at a grade of 0.45% copper has already been established by the Company through 5,000m of drilling. Around 5km southwest of M2, three holes have been drilled at M4 with interesting shows which merit follow-up drilling in due course. Last year the Company staked new claims in an area known as Yellow Peak, located 5km north of M2, where further indications of a porphyry system have been observed by Great Western's field team. 

West Huntoon, M4 and the inferred resource at M2 occur within a circle which has a 6km radius. Great Western's aim is to establish a single copper deposit connected across the Huntoon Valley and the drilling programme proposed at West Huntoon this year is the next stage in pursuing this aim.

A copper mine in the Huntoon Valley on the scale envisaged will be a massive, long-term undertaking, beyond the capabilities of Great Western to accomplish alone, and for some time the Company has been engaging with larger companies with a view to finding an industry partner. Given that copper is now a designated critical mineral in the USA, the Company believes that the Huntoon Copper Project has considerable potential value for Great Western's shareholders, but it remains an early-stage project. Accordingly, the Company believes that a limited drill programme at West Huntoon to verify surface indications will be in its best interests and help secure a favourable deal with potential partners. Five drill holes at an average depth of 200 metres are planned for this Summer's work season, to move the prospect to the next stage. 

RHYOLITE DOME GOLD PROSPECT

For the last two years, Great Western's main exploration focus has been on the significant Huntoon Copper Project but, in an era of record gold prices, the Company's gold prospects remain important to its portfolio. Rhyolite Dome is the most prospective undrilled target on the Company's Olympic Gold claims and one of the most prospective gold targets across Great Western's entire portfolio. Geophysics and drilling at Rhyolite Dome are planned this year. An IP survey will be used to target five drill hole locations at Rhyolite Dome, each hole estimated to be 100m. Rhyolite Dome is situated in the south of the Olympic Gold Project, 1.5km to the southeast of the OMCO Mine along the key Olympic Gold fault zone. Great Western has compiled a compelling set of overlapping exploration indicators at Rhyolite Dome. The Olympic Gold claims lie within a well-mineralised epithermal district in the Walker Lane Trend.

DEFENDER & PINE CROW TUNGSTEN PROSPECTS

Tungsten is another metal currently on the USA's critical list. On the fringes of Great Western's claims are two old, shallow tungsten mines, known as Defender and Pine Crow, approximately 1.2km apart. In 2024, the Company staked further claims to provide a halo around these two old workings and in early 2025 carried out field work, including grab and soil sampling, over the area. Lab. results are pending and will be released when available. This early-stage exploration project, in an area where surface tungsten has been produced in two separate workings in the past, offers another highly prospective licence to Great Western's portfolio.

EASTSIDE MINE/TANGO COPPER POOLING AGREEMENT

The Eastside Mine/Tango pooling agreement is a cooperation arrangement with Bronco Creek Exploration (BCE), a division of EMX Royalty Corporation, for promoting and farming out a copper porphyry prospect of similar quality to the Company's West Huntoon prospect, located approximately 18 km to the southeast. The Company has contributed its Eastside claims to this venture and is consequently a 30% participant in the pooling agreement which comprises 2,823 acres (1.142 hectares). Post-signing the BCE pooling agreement, Great Western and BCE have staked further claims to extend the prospect in the ratio of the pooling agreement ownership. The Company has carried out a recent IP survey over Eastside, identifying strong chargeability anomalies at positions never previously drilled and associated with surface copper anomalies. BCE is the lead partner in the venture and is actively seeking additional partners.

CLAIMS MANAGEMENT

Great Western's claims in Nevada currently cover approximately 60km². Over the last year, new claims have been staked (1) at Yellow Peak in the northern part of the Huntoon Copper project area where there are strong surface indications of a continuing copper porphyry setting, (2) around the Pine Crow and Defender former tungsten mines which lie on the fringes of the Company's existing claims (3) to extend the area of the Eastside/Tango pooling agreement and (4) at Rock House. In parallel, all existing claims have been reviewed and a decision taken to reduce claims where there is no clear prospectivity and no work imminently planned, in most cases keeping a small number of these claims as insurance in the event of third-party activity. This will reduce the area of the portfolio by approximately one third which is a sensible revision of the Company's portfolio and will consequently result in a net annual cost saving in claim rentals of approximately $50,000.

TECHNICAL PERSONNEL

Great Western is pleased to welcome Dr. Lawrence Carter as a retained consultant to the Company. Dr. Carter is a geologist and a recognised expert on copper porphyry systems, having already proved invaluable to the company in establishing a porphyry setting at West Huntoon, his report on which is available on the Company's website. His ongoing involvement will be of great advantage in developing the Huntoon copper story.

Gemma Cryan, a non-executive director since 2021, becomes Geology Manager of the Company for the duration of the proposed drill campaign. Gemma Cryan is a 20-year geologist who has worked globally in early-stage exploration for both precious and base metals. She was Head of Geology at Greatland Gold PLC and a senior geologist at Hummingbird Resources PLC, involved in multimillion ounce gold discoveries at both companies.

ISSUE OF WARRANTS

The Company's joint broker, Shard Capital Partners, will be issued warrants over 7,500,000 new ordinary shares in the Company. The warrants will be exercisable for a period of 24 months from the date of Admission with an exercise price of 1p per new ordinary share ("Broker Warrants").

ADMISSION OF NEW SHARES AND TOTAL VOTING RIGHTS

Further to the Placing, admission of 125 million Ordinary Shares to trading on the AIM and Euronext Growth markets is expected to occur on 24 June 2025 ("Admission"). The Placing is conditional on Admission. 

Following Admission of the Placing Shares, the Company's issued ordinary share capital will comprise 177,189,274 Ordinary Shares of €0.0001. There are no Ordinary Shares held in treasury. Accordingly, this number will represent the total voting rights in the Company, and, following Admission, may be used by shareholders as the denominator for the calculation by which they can determine if they are required to notify their interest in, or a change to their interest in, the Company under the Transparency (Directive 2004/109/EC) Regulations 2007. The new Ordinary Shares will rank pari passu in all respects with the Ordinary Shares of the Company currently traded on AIM and Euronext Growth.

QUALIFIED PERSON STATEMENT

The technical information in this announcement that relates to exploration results is based on information reviewed by Dr James Blight MGeol PhD MAusIMM who is Chief Geologist of Great Western Mining Corporation PLC. Dr Blight is a "Qualified Person" as defined in the "Note for Mining and Oil & Gas Companies" which form part of the AIM Rules for Companies. Dr Blight has reviewed and consented to the inclusion in the announcement of the information in the form and context in which it appears.

THIS ANNOUNCEMENT CONTAINS INSIDE INFORMATION IN RELATION TO GREAT WESTERN MINING CORPORATION PLC.

For further information:

Notes to Editors

The Company has a large tract of acreage in Mineral County, Nevada. The area consists of rugged, mountainous terrain, which means that large parts of it remain under-explored. Mineral potential is hosted by the regional Walker Lane Structural Belt, the largest structural and metallogenic belt in Nevada, yet one of the least explored in recent times, with gold, silver and copper currently produced in Mineral County. Great Western has seven distinct concession areas which offer the potential for exploiting (1) short term gold and silver deposits and (2) long-term, world-class copper deposits. 

Six of the Company's properties are in the west of Mineral County and the seventh and most recent acquisition, the Olympic Gold Project, is in the east of the county, some 50 miles from the main group. All the Company's claims are 100% owned. Claims at the Eastside Mine Group have been contributed to a pooling agreement with Bronco Creek Exploration, Inc. and in addition the Company participates in the Huntoon Mine Area Cooperation Agreement with landowner-neighbour Crowne Point Resources with whom it shares resources. Great Western's small exploration team is supported by locally based consultants and contractors. 

The state of Nevada is one of the world's most mining friendly jurisdictions. While tightly regulated and environmentally conscious, Nevada welcomes the mining industry. Great Western takes care to ensure that its claims are maintained in good standing and all regulations observed. 

There are numerous gold and silver prospects on the Company's acreage, including extensive historic mine workings which offer the opportunity for secondary recovery. The Company is party to a 50-50 joint venture known as Western Milling LLC which is constructing a mill to process pre-mined material for secondary recovery of gold and silver.

Furthermore, through extensive drilling over a five-year period, GWM has established a Mineral Resource on its first target area known as M2, of 4.3 million tonnes at 0.45% copper, for 19,000 tonnes of contained copper metal. This resource has been independently reported in accordance with JORC guidelines. 

GWM has also established an Inferred Resource Estimate of 31,000 tonnes grading 1.6 g/t gold and 3.0 g/t silver in tailings associated with the OMCO Mine at the Olympic Gold Project. Additionally, exploration targets have been independently reported as follows:

· 3,400 - 6,400 tonnes grading between 0.5 and 1.2 g/t Au and 1.2 and 2.1 g/t Ag in the substrate beneath the tailings volume at the Olympic Mine.

· 9,000 - 12,000 tonnes grading between 0.9 and 2.4 g/t Au and 2.0 and 5.1 g/t Ag in a coarse stockpile at Olympic Mine.

· 4,200 - 7,700 tonnes grading between 40 and 140 g/t Ag and 0.3 and 0.3 g/t Au in spoil heaps at Mineral Jackpot.