Diablo Resources (ASX: DBO) has identified a broad, high-grade polymetallic system at its Horn Silver Project in Utah, with initial reconnaissance sampling returning significant silver, gold and copper mineralisation across several prospects.

The company collected 66 rock samples across the project's unpatented claims, targeting historical workings, extensions of known anomalies and areas that had not previously been recognised as mineralised. Horn Silver is a historic mining area, with past production dating back to the late 1800s, and Diablo's programme was designed to test whether mineralisation extends beyond the old workings at surface. The results are rock chip samples, which indicate the presence and grade of mineralisation at surface but are an early-stage indicator that requires drill testing to establish continuity at depth.

According to Diablo, the results have strengthened its exploration pipeline and identified several areas that could now progress towards drilling. The company described the findings as confirmation of a broader district-scale mineralised footprint.

The strongest results came from the Washington Prospect, where samples returned up to 1,730 g/t silver and 5.74 g/t gold, while another sample delivered 1,475 g/t silver, 7.57 g/t gold and 3.37% copper.

At the Buckhorn Prospect, a standout sample returned 4,190 g/t silver, 1.40 g/t gold and 2.41% copper.

The Michigan Prospect also produced high-grade gold alongside silver and copper, while sampling at Accrington returned further strong silver and copper results.

At Washington, Diablo has identified a roughly 950-metre west-northwest trending corridor containing historical workings and surface mineralisation associated with altered carbonate and skarn rocks. Skarn-hosted systems of this type are a recognised setting for polymetallic mineralisation in mining districts of the western United States. The company believes the latest results underscore the importance of the structural corridors associated with the historic mine and provide additional evidence that mineralisation extends across a much larger area.

Diablo CEO Lyle Thorne said the results had strengthened the company's pipeline of critical minerals targets and highlighted multiple zones containing silver, gold, copper and antimony. Antimony is designated a critical mineral by the US government, adding policy-level relevance to the project's polymetallic inventory.

The company is now moving towards drill planning at Horn Silver, with the objective of testing the most prospective mineralised structures identified through the sampling and geological work. With Horn Silver drill planning underway and North Star drilling approaching, Diablo is positioning itself for a potentially active period of exploration news flow.