Sentinel Metals Limited has intersected 46.8 metres at 5.5 g/t gold from 88.2 metres down-hole in the maiden diamond drill-hole at the Columbia Gold-Silver Project in Montana, USA.

The initial hole, designated DDCO26-001, included a higher-grade core of 21.4 metres at 11.1 g/t gold from 97.6 metres, which brackets a 13.5-metre interval grading 16.6 g/t gold from 105.5 metres. The high-grade zone is supported by mineralisation above and below, returning 17.3 metres at 1.1 g/t gold with 88% recovery and 16.0 metres at 1.0 g/t gold with 99% recovery respectively.

Core recovery through the central 105.5 to 119.0-metre interval averaged 20%. Sentinel stated that sampling bias cannot be discounted here, meaning reported grades over low-recovery intervals are indicative only. The company has transitioned to triple-tube drilling to optimise core recovery and intends to re-drill the interval.

The drilling confirmed that gold mineralisation persists into fresh rock below the redox boundary at approximately 135 metres down-hole, achieving 95% to 100% core recovery in fresh material. Historical operators typically stopped drilling at this boundary to target oxide heap-leach feed.

“Our first hole at Columbia has achieved two things. Firstly it has returned a strong maiden intercept of 46.8 metres at 5.5 grams per tonne, including 13.5 metres at 16.6 grams per tonne. Secondly it confirms that gold continues into fresh rock beneath the oxide blanket - rock that historical operators typically stopped at as they were drilling for oxide heap-leach feed.

Beyond the strong gold result, our first hole has provided important insights into the geological and drilling characteristics of the Columbia system. The program has already enhanced our understanding of the oxide profile and ground conditions, allowing us to further refine drilling techniques. We have now transitioned to triple-tube drilling to optimise core recovery as we progress the program and, importantly, there is no indication at this stage that recovery characteristics have adversely impacted the reported gold grades.

We are excited to have made such a strong start to our maiden drilling program at Columbia, and we look forward to receiving additional assay results in the weeks and months ahead.”

— Matt Herbert, Managing Director

Sentinel commenced environmental baseline studies at Columbia in February 2026 to support permitting pathways, following a $10 million initial public offering in October 2025.

Upcoming catalysts include multi-element and fire assays for hole DDCO26-001, alongside the completion of the 21-hole maiden diamond drilling program. Assays for holes DDCO26-002 to DDCO26-005 remain pending.

Read the full announcement: Maiden Columbia drill-hole returns 46.8m at 5.5 g/t gold