Horizon Gold eyes bigger WA mine after spectacular hits

Horizon Gold has unleashed a volley of high-grade gold hits from recent drilling at its sprawling 100 per cent-owned Gum Creek project in Western Australia’s Murchison region, headlined by a stunning 44-metre intersection grading 5.08 grams per tonne (g/t) gold.

The eye-catching result came from Snook, a prospect highlighted by two historic pits 24.5km north of the Gidgee mill. It returned 11m at a stellar 16.3g/t gold from 174m downhole in the deepest drilling yet at the prospect, with a conga line of impressive intercepts pointing to potential for a much larger open pit and a possible underground operation.

Other standout results included 14m at 5.18g/t from 88m, featuring an 8-metre zone at 8.81g/t and 12m at 5.72g/t from 135m, including 5m at a solid 10.93g/t. A deeper hit returned 14m at 4.12g/t from 204m, with an impressive three-metre section at 15.33g/t.

Heading into the campaign, Snook carried a 54,000-ounce resource defined across 550m of strike and up to 70m wide. The 25-hole, 5151m reverse circulation (RC) program is aiming to push that resource down-plunge to the south. Horizon says the drilling has now confirmed mineralisation to a depth of up to 230m below surface and further defined a steeply south-plunging high-grade system beneath both historic pits.

‘Infill drilling at Alma May and Cobia is on track to deliver maiden resources over the coming months.’

Horizon Gold managing director Scott Williamson

Drilling at the Cobia prospect, 26km north of Gidgee, has confirmed mineralisation continuing south of the old pit, with a notable hit of 21m at 2.08g/t from 76m, including 15m at 2.68g/t. Although Cobia was previously open-pit mined, the prospect has no current resource.

At Alma May - another former open-pit operation 26.5km north of Gidgee with no current resource - 14 holes covering 964m tested shallow ground along strike to the north. Results included 5m at 2.79g/t from 26m, with a one-metre slice at 12.5g/t. Drilling confirmed gold in weathered, quartz-veined rock and room to extend mineralisation north of the pit.

Horizon Gold managing director Scott Williamson said: “With follow-up drilling already underway across multiple prospects and further programs planned, we see meaningful scope to enhance project economics well beyond the recent DFS.”

Horizon expects to deliver maiden resource estimates for Alma May and Cobia over the coming months, while a resource update is also planned for the high-flying Snook prospect. Once complete, drilling will resume, including diamond work south of the Cobia pit, shallow infill and extension programs, and pit optimisation at Alma May.

The latest results add another layer of intrigue to Horizon’s broader Gum Creek development ambitions, which are built around a substantial gold inventory and an established mining district with a long production history.

Gum Creek, 640km northeast of Perth, is a classic brownfields revival story. More than one million ounces have been produced from 37 open pits and three underground mines, while a 110-person camp, operational airstrip and extensive haul roads give Horizon a substantial development head start.

Operations ceased in 2005, when gold was languishing at A$560 an ounce. Today’s much stronger gold market gives Horizon a very different launchpad.

The company’s July definitive feasibility study (DFS) outlined a robust plan for a new 2.4-million-tonne-a-year processing plant at Gidgee, underpinned by a 728,000-ounce ore reserve. It envisages a 10-year operation producing an average of 88,000 ounces a year, peaking at 114,000 ounces in year two and recovering 880,000 ounces over the mine life. It forecasts pre-production capital of A$350M and an all-in sustaining cost of A$2,995 an ounce.

The real kicker is that this starter case draws on only a fraction of Gum Creek’s global resource of 37.97 million tonnes grading 1.89g/t for 2.3 million ounces of gold. A 416,000-ounce free-milling underground resource and the 400,000-ounce Wilsons sulphide deposit also sit outside the current mine plan, offering further growth beyond the DFS case.

Snook, Cobia and Alma May are similarly excluded from the initial mine plan, so success across the three prospects could add significant scale to the project’s already substantial gold inventory.

Alongside its work, Horizon is targeting a final investment decision on the company’s main Gum Creek development in the second quarter of 2027, with first gold targeted in the second half of 2028.

Horizon has a solid DFS in its back pocket and high-grade hits emerging beyond the initial mine plan at Cobia, Alma May and Snook. The new resource estimates could add further weight to the growth story, showing the DFS may be just the floor, not the ceiling.

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