Great Boulder Launches 40,000m Drilling to Expand 481,000oz Peak Hill Resource

Major Drilling Campaign Targets Resource Growth at Peak Hill

Great Boulder Resources (ASX:GBR) has mobilised two reverse circulation (RC) rigs and will soon add a diamond rig to launch a 40,000-metre drilling program at the Peak Hill Gold Project in Western Australia. The campaign aims to infill and extend the existing 481,000oz gold resource, with a particular focus on high-grade zones such as the Golden Treasure area, where previous drilling by Westgold Resources returned impressive intersections including 19 metres at 13.34 grams per tonne (g/t) gold.

The company plans to deliver a resource update by the end of calendar year 2026, setting the stage for mining studies scheduled for early 2027. This ambitious timetable underscores Great Boulder’s commitment to rapidly advancing Peak Hill from acquisition to production readiness.

High-Grade Targets and Historical Drilling Highlights

The drilling program targets multiple deposits within the Peak Hill project, including Jubilee, Durack, Enigma, Harmony, and Five Ways, alongside brownfields exploration at Golden Treasure. Historical drill results from Golden Treasure are particularly compelling, with intercepts such as 10 metres at 18.79 g/t gold and 3 metres at 25.04 g/t gold recorded in 2025.

These results indicate substantial high-grade mineralisation outside the current resource boundaries, providing a strong rationale for the ongoing campaign. The RC rigs are actively drilling at Golden Treasure, Jubilee, and Durack, with further work planned at Enigma, Harmony, Mt Pleasant, and Five Ways.

Strategic Agreements Support Capital-Light Production Pathway

Great Boulder’s acquisition of Peak Hill includes a Mining and Heritage Agreement with the Jidi Jidi Aboriginal Corporation, facilitating community collaboration as development plans advance. Critically, an Ore Purchase Agreement (OPA) with Westgold grants access to processing capacity at one of Westgold’s regional mills, enabling Great Boulder to commence production without the capital-intensive and time-consuming process of building a standalone mill.

This arrangement provides a capital-light pathway to cash flow, reducing upfront investment hurdles and accelerating the project’s timeline. The company also holds a non-binding collaboration agreement that could extend similar processing arrangements to its 1.02 million ounce Side Well gold project, where drilling continues with 20,000 metres planned for the current half-year.

Resource Base and Forward-Looking Development Plans

The current Peak Hill resource stands at 481,000 ounces gold, classified as indicated and inferred across multiple deposits. The resource estimates incorporate extensive historical drilling data and geological modelling compliant with JORC Code standards. Bulk density and metallurgical assumptions reflect the project’s long history of successful open-pit gold mining.

Following the resource update targeted for late 2026, Great Boulder intends to commence mining studies in early 2027 to define open pit development sequencing and support mining approvals. The company has demonstrated operational agility by establishing a camp with essential infrastructure within weeks of acquisition completion, signalling readiness for sustained exploration and development activity.

Parallel Exploration at Side Well and Regional Positioning

Alongside Peak Hill, Great Boulder is advancing its Side Well project with ongoing drilling designed to expand its 1.02 million ounce resource. The company anticipates mobilising an additional RC rig in August to accelerate testing of priority targets. The proximity of Peak Hill to Side Well and regional mills positions Great Boulder favourably within the Murchison gold district, leveraging existing infrastructure and geological continuity.