Great Western Mining Corporation PLC / AIM: GWMO / Euronext Growth: 8GW

1^st  September 2025

GREAT WESTERN MINING CORPORATION PLC

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

Exploration Update

Drilling set to test high-potential gold and copper targets across Nevada portfolio

Great Western Mining Corporation PLC, a strategic and precious metals exploration and development company, is pleased to provide an update on exploration activities at key targets in the Walker Lane belt of Nevada, USA.

HIGHLIGHTS

·    Signed a rig contract for approximately 1,800 metres of RC drilling at Rhyolite Dome and West Huntoon commencing early October.

·    Completed an IP survey at the previously undrilled Rhyolite Dome gold prospect, defining drill targets.

·    Completed soil sampling at the Defender-Pine Crow tungsten prospect, with laboratory analysis now underway.

·    Work ongoing at recently staked Yellow Peak claims, using recent soil sampling and evaluation of historical drill data to expand the West Huntoon copper footprint.

Great Western Chairman Brian Hall commented: "We are pleased to announce that our planned drilling programmes at Rhyolite Dome and West Huntoon will commence in early October, following the recent signing of a contract with HD Drilling LLC. These two campaigns will test high-potential gold and copper targets, convert surface anomalies into measurable mineralisation and de-risk our assets. Combined with the recently completed IP survey at Rhyolite Dome and strategic staking at Yellow Peak, we are taking a disciplined, data-driven approach to unlock the significant value potential across our Nevada portfolio. Results from these programmes are eagerly anticipated and will guide the next stage of exploration."

DETAILS

Upcoming Drilling - Rhyolite Dome Gold & West Huntoon Copper Prospects

Great Western has signed a drilling contract with HD Drilling LLC of Winnemucca, Nevada, for programmes at the Rhyolite Dome gold prospect and the West Huntoon copper porphyry prospect. Drilling is scheduled to commence in early October, using a track-mounted reverse circulation (RC) rig, and is expected to total approximately 1,800 metres across both projects over a four to six-week campaign.

At West Huntoon, drilling will focus on validating surface copper mineralisation at depth, supporting an independent report which indicates the presence of a porphyry system and reducing exploration risk by converting surface anomalies into measurable subsurface mineralisation. Great Western has previously drilled a single hole at West Huntoon in search of gold, which intersected 45.7 metres at 0.27% Cu. In addition to the new drilling, the Company has secured access to unassayed cuttings from two historical holes drilled by a prior operator. These are being analysed to enhance geological understanding and complement ongoing exploration.

At Rhyolite Dome, a scout drilling programme is planned. Located in the southern part of the 840-acre Olympic Gold Project, this prospect lies within a structural crossover zone between northwest and north-northeast trending faults but has never been drilled. Drill targets will be based on the recently completed IP survey. Notably, the Olympic Gold Project encompasses the historic OMCO Mine, which produced high-grade gold between the two world wars. Great Western has already intercepted gold at nearby Trafalgar Hill and along extensions of the OMCO system.

Geophysical Survey - Rhyolite Dome Gold Prospect

An induced polarisation (IP) geophysical survey has been successfully completed at the Rhyolite Dome prospect. This undrilled epithermal gold target is being advanced using proven geophysical techniques to define drill targets accurately and optimise hole placement as part of a structured exploration strategy.

Yellow Peak Prospect

Earlier this year Great Western staked strategic new claims at Yellow Peak, located north of and on trend with West Huntoon's porphyry potential. This acquisition provides access to a significant set of historical drill cores from a previous operator. The Company's technical team is currently evaluating these cores, with results being integrated into the geological database. The expanded dataset will support the design of an optimised exploration programme across the broader Huntoon area.

Soil Sampling - Tungsten Prospect

In August, the Great Western field team completed a systematic soil sampling grid adjoining and between the historic Defender and Pine Crow tungsten workings, where earlier grab samples returned high tungsten grades. All samples have been delivered to a laboratory in Reno, Nevada, for analysis. Results will be released once received, timing of which will depend on the lab's current workload.

ENDS

For further information visit www.greatwesternmining.com or contact:

Notes

Great Western Mining Corporation PLC (AIM: GWMO / Euronext Growth: 8GW) is a diversified exploration and development company focused on strategic minerals across several 100%-owned claim groups in Mineral County, Nevada, one of the world's most prolific and mining-friendly jurisdictions. Backed by an experienced team, the Company is pursuing a multi-commodity strategy targeting near-term development and longer term exploration while assessing farm-out and joint venture opportunities to unlock broader portfolio value. As well as its flagship Huntoon Copper Project, which hosts a JORC-compliant resource of 4.3 Mt at 0.45% Cu, with upside from undrilled porphyry targets, it has a pipeline of gold, silver, and early-stage tungsten assets aligned with US critical minerals priorities.