Placer mining, the mining of stream beds for minerals, was common practice in the area since the mid nineteenth century.
The Mount Polley ore deposit was discovered subsequent to an airborne magnetometer study completed by the Canadian government in 1964 which detected a significant reading for the surveyed map in the region of Polley Mountain. Investigating further, Karl Springer discovered an alkalic porphyry deposit there the same year.
Quintana Resources prospected the area in 1976, discovering numerous copper float boulders but let their claim to the property lapse in 1978. In 1980, E&B Exploration optioned the property from Highland Crow, a subsidiary of Teck. Through the early 1980s, the potential for gold mining on the site was explored due to the rising global price of the commodity.
The first feasibility study for the site was completed in 1991 and the first permits for developing the deposit were approved the same year. Financing from Imperial Metals however was not yet in place.