The region in which the showing occurs is within the Inter- montane Belt, underlain dominantly by Lower to Middle Jurassic volcanic and sedimentary rocks of the Hazelton Group. These as- semblages are overlain by the Upper Cretaceous to Lower Tertiary Ootsa Lake Group and Miocene plateau basalt. Intruding Lower Jurassic rocks of the Hazelton Group in the northeastern part of the map sheet is a belt of granodiorite, diorite and quartz diorite plutons of the Lower Jurassic Topley intrusive suite. Felsic plutons of probable Cretaceous age intrude both Lower and Middle Jurassic Hazelton strata.
An Upper Triassic aged belt of massive to banded grey limestone extends northeastward for 6.4 kilometres, 2.5 to 6.5 kilometres south of Kuskoil Lake. The belt varies up to 1300 metres wide, averaging 800 metres in width. The limestone is bounded to the northwest by conglomerate, shale and greywacke of the Upper Triassic Takla Group. To the southeast it lies in fault contact with Jurassic argillite, greywacke and conglomerate of the Hazelton Group.