Several large mining and exploration companies have completed regional appraisals of the district for mineral sands, gold, uranium and base metals. In the 1990s, exploration was common for lignite and brown coals, with several coal mining leases taken out in the eastern part of the Mt Ridley Project area. In the early 2000’s, well before the discovery of Nova-Bollinger, a significant 60x15km coincident gravity-magnetic feature, known as the Grass Patch Complex, was recognised by large resource companies. It was researched for a new, large layered mafic intrusion with the potential to host nickel-copper sulphide deposits and PGE deposits.