Riverside Resources has announced preparation for the next phase of drilling at the La Union Project in Sonora, Mexico is underway, with operations expected to commence in November 2026.
The company, operator of the project, is collaborating with option partner, Questcorp Mining, with funding provided through an existing option agreement.
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With the conclusion of the rainy season, Riverside Resources has begun road works and construction of drill pads required for the new exploration campaign, named Phase 2B.
The programme will include approximately 600m of reverse circulation (RC) drilling, split between two holes around 300m each.
The drilling is set to focus on two key targets, including Luis Hill and the Union Mine.
RC drilling has been chosen for this phase due to its ability to penetrate at a faster rate and provide larger sample volumes compared to core drilling.
According to the company, core drilling in earlier phases encountered significant faulting and issues with recovery.
RC drilling is also expected to enable dry drilling, as previous core holes did not intersect water, which the company cites as potentially beneficial for speed and cost.
At Luis Hill, the planned RC hole will target a chargeability anomaly identified by an induced polarisation (IP) survey, which stretches over 1km and coincides with sediment-hosted gold mineralisation discovered during earlier drilling stages.
The Union Mine hole aims to extend exploration following previous chip-channel sampling, which returned grades including 20.2g/t gold and 226g/t silver, as well as 2.7% zinc over a 30m length.
Diamond drilling in the prior Phase 2A, totalling 530.1m, was limited by geological complications. One hole at Luis Hill did not reach its intended depth.
The company will use results from the forthcoming programme to assess the wider applicability of RC drilling at La Union.
The La Union Project is situated within the Clemente Formation, with mineralisation targets in both sedimentary and carbonate replacement deposit environments.
Riverside Resources president and CEO John-Mark Staude said: “The Phase 2A exploration programme outlined a large IP target at Luis Hill and continuity of mineralisation at Union.
“Phase 2B plans to test both of these targets with RC drilling. We expect RC drilling to advance more efficiently through the faulted ground encountered during core drilling.”
In July 2026, Riverside received expanded property package mineral titles for its Revel and Red Jacket projects in south-central British Columbia.
