Au-Ag-Cu Mineralisation Confirmed at West Huntoon

Great Western Mining Corporation PLC (AIM - GWMO, Euronext Growth - 8GW) is pleased to announce the assay results of a Reverse Circulation ("RC") drilling campaign at its West Huntoon Gold-Silver-Copper Project in Nevada USA ("the Project").

HIGHLIGHTS

• Six RC drill holes successfully drilled at West Huntoon, totalling 3,630 ft (1,106.4 metres) (Figure 1) providing valuable new insights into the precious and base metal mineralisation of the Project.
• Precious metal Au-Ag mineralisation is now found to be associated with Cretaceous "Crown Point" granite (Figure 1, Table 1).
• Highlight metal intercepts include:

o 25 ft @ 1.01 g/t Au and 11.00 g/t Ag (including 5 ft @ 2.55 g/t Au and 19.00 g/t Ag);

o 15 ft @ 1.67 g/t Au and 2.34 g/t Ag (including 5ft @ 4.01 g/t Au and 2.74 g/t Ag);

o 5 ft at @ 1.06 g/t Au and 8.54 g/t Ag; and 85 ft @ 3.00 g/t Ag (Table 1).

• Elevated pathfinder elements including barium (Ba, consistently >2,000 ppm), arsenic (As, various 5ft intervals >1000 ppm and up to 3670 ppm), lithium (Li, consistently >20 ppm) and antimony (Sb, various intervals >4 ppm) in all drill holes indicate a shallow component of a magmatic-hydrothermal system.
• Previously unexamined material from historic RC and diamond core drilling has recently been obtained by the Company and will be logged and assayed.
• Detailed geological mapping and sampling of epithermal features across the property is ongoing.

Great Western Chairman Brian Hall commented: "The results of our focused but limited drilling campaign over part of the vast area which makes up the Huntoon Copper Project have delivered strong potential for significant gold and silver mineralisation in addition to the copper potential which we had already established. Confirmation of precious metals mineralisation over the Crown Point area is a major advance for the Company and will add an important new dimension to our 2026 exploration plans as we move forward, which will include further testing of the Crown Point granite.

"In particular, these results establish the gold and silver fertility of the Crown Point granite which had never previously been recognised until identified by the GWM team in 2023. This will help us better understand the soil and rock anomalies we have extensively mapped at surface. Assessment of the fertile granite will be a focus at West Huntoon, together with additional work targeting and delineating copper. Further testing of the Crown Point granite will be a major play moving forward.

"Notably, this work sits alongside a broader, multi-commodity exploration portfolio located within the Walker Lane Trend, a tier-one, mining-friendly jurisdiction with world-class geology, established infrastructure and low geopolitical risk, aligned with the U.S. 'America First Metals' strategy to strengthen domestic supply chains. This includes our strategic tungsten targets, where we expect to receive results shortly from trench sampling following previously identified anomalous soil results."

Table 1: Highlight intervals from the West Huntoon 2025 RC drilling campaign. Co-ordinates in EPSG 26911

Figure 1: Satellite image and simplified geological map of the West Huntoon project, with previously reported grab and soil samples and drill hole collars from this campaign plotted. Coordinates in EPSG 26911.

BACKGROUND

The West Huntoon Gold-Silver-Copper Project is part of the Huntoon Copper Project, located in Mineral County, Nevada, within the Walker Lane Structural Belt. Late Proterozoic to Mesozoic rocks, mainly Permian Mina Formation and Jurassic Dunlap Formation, outcrop in the project area, intruded by Cretaceous granites, granodiorites and diorites, which are largely covered by post-mineral Tertiary volcanics. The Cretaceous "Crown Point" granite, recently discovered and mapped by the Company, contains textural evidence for having hosted magmatic-hydrothermal fluid flow and mineralisation.

The 2025 RC drilling programme at the West Huntoon Prospect was designed to test the potential for magmatic-hydrothermal type mineralisation associated with coincident geologic mapping, soil and rock chip Cu-Au-Ag geochemical anomalies and IP geophysical targets. Six holes together totalling 3,630 ft/1,106.4 metres were completed.

Additionally, in 2025, the Company obtained previously unexamined material from historical RC and diamond drilling at West Huntoon. The Company plans to log and assay this material in the near-term, whilst also undertaking further detailed mapping and sampling of epithermal mineralised features across the wider West Huntoon area.

ADDITIONAL INFORMATION

RC chip samples were collected at 5ft intervals and submitted to ALS laboratories, Reno, Nevada. Samples were analysed by methods ME-MS61 and Au-AA25. Quality control samples (duplicates, blanks and certified reference materials) were inserted by the Company and results reviewed prior to release. Down hole surveys were completed for every hole.

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.