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

21 October 2025

GREAT WESTERN MINING CORPORATION PLC

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

Drilling Update

West Huntoon Drilling Completed; Rhyolite Dome Programme Underway

Great Western Mining Corporation PLC, a strategic minerals exploration and development company, is pleased to announce the successful completion of its reverse circulation ("RC") drilling programme at the West Huntoon copper prospect in Mineral County, Nevada and the commencement of drilling at the highly prospective Rhyolite Dome gold target.

The six-hole programme at West Huntoon, the Company's flagship copper asset, was completed ahead of schedule and without incident, totalling 3,615 feet (1,102 metres). West Huntoon lies within a richly mineralised valley system that hosts multiple copper prospects within a 6 km radius, underscoring the broader potential of this emerging copper district. Samples from all holes are being dispatched for laboratory assay, with results expected in the coming weeks.

Following completion of the West Huntoon phase, the drill rig has been mobilised to the high-priority Rhyolite Dome target, a large, previously undrilled, silica-flooded system displaying strong epithermal indicators at the Olympic Gold Project. The six-hole programme now underway is designed to test several shallow anomalies identified by a recent induced polarisation ("IP") geophysical survey and is expected to conclude during October.

Brian Hall, Chairman of Great Western Mining, commented: "Our exploration campaign in the Walker Lane Belt continues to gather real momentum. Completing the West Huntoon programme represents another significant milestone as we systematically test a pipeline of highly prospective targets across our Nevada portfolio. Mobilising immediately to Rhyolite Dome keeps our field operations moving at pace and we are excited by the potential of this previously undrilled system. With assay results due in the coming weeks, we look forward to sharing further progress with shareholders in what promises to be a very active quarter for the Company."

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.