The Chilcotin River East showing is located within the Inter- montane Belt underlain by volcanic rocks of the Jurassic Hazelton Group and Tertiary volcanics of the Ootsa Lake and Endako Groups, overlain by Miocene plateau basalt. Intruding the Mesozoic volcanic and related sedimentary rocks of the Hazelton Group are small complexes of foliated granodiorite and diorite, often showing complex mixed relationships with intrusive and supracrustal rocks. Younger undeformed quartz porphyry dikes, possibly related to the overlying Ootsa Lake Group cut these older rocks.

The Chilcotin River East showing consists of copper mineraliz- ation within the Upper Cretaceous to Lower Tertiary Ootsa Lake Group intermediate to felsic volcanic and related rocks.