The area is mainly underlain by Lower Jurassic Hazelton Group volcanics of the Telkwa Formation which are intruded by Early Jurassic Topley Intrusions. Mineralization occurs in veins and fractures in andesitic volcanic rocks and consists of chalcopyrite, bornite, calcite, and hematite. A 1928 report referred to mineralization along bedding planes and a sample gave 137.1 grams per tonne silver and 6.0 per cent copper (Minister of Mines Annual Report 1928, page 177).