This is part of the first earn-in stage for Rio Tinto to acquire a project interest of 55 per cent in Frisco, by spending $US6 million ($9 million) of exploration expenditure.

Rio Tinto assessed ground conditions to determine the logistics and safety requirements of its drill program, and reviewed select drill holes to understand the geology of the area in March.

The company now plans to drill high-grade intersections at the Cactus breccia and Accrington skarn targets, and complete deeper hole testing at the Reciprocity induced polarisation (IP) anomaly.

The initial 200-metre, four-hole drill program commenced last week, with Rio Tinto testing the Cactus breccias hole for potential continuity of mineralisation between the Cactus and Comet breccias.

Meanwhile, Rio Tinto will test a step-out zone 50 metres from historic intercepts at Accrington skarn to determine continuity in the area.

At the Reciprocity target, the company’s remodelled geophysical data shows a previous hole drilled by Alderan might have been terminated before reaching the depth of the anomaly.

Rio Tinto and Alderan are working with the Utah Division of Oil, Gas and Mining to permit near-term drilling activities.

Fifteen previously permitted drill sites have been transferred from Alderan to Rio Tinto to advance the project.

Rio Tinto can earn up to 70 per cent of interest in Frisco by spending $US30 million in exploration expenditure.