Slate was quarried on a Reserve at Deserted Bay on the east shore of Jervis Inlet, 22 kilometres southeast of the head of the inlet. The region near the head of Jervis Inlet is underlain by an irregular, northwest trending roof pendant comprised of tuff, breccia and argillite of the Lower Cretaceous Gambier Group. The pendant occurs in Jurassic to Tertiary Coast Plutonic Complex rocks.

The stone at the Deserted Bay quarry consists of a finely laminated black carbonaceous slate free from significant impurities. Cleavage is developed perpendicular to indistinct horizontal to shallow dipping bedding. The slate is cut in places by quartz and calcite veins and by small granite dykes.

The quarry was first opened in 1890 and was reopened briefly in 1907, when slate was exported to California, and also used in a number of barracks of the North West Mounted Police. The quarry was active again in 1957 and 1958 when British Columbia Slate Company Ltd. produced slate for flagstone and tile. Approximately 600 tonnes of slate was quarried and shipped to Vancouver over these two years.