The California occurrence is at the north end of Silver Cup Ridge. It is probably west of the head of Sharon Creek, as indicated by Fyles and Eastwood (EMPR BULL 45). Sharon Creek is a northeasterly flowing tributary of Lardeau Creek. An adit was driven on the California vein sometime prior to 1962.
The Trout Lake area is underlain by a thick succession of sedimentary and volcanic rocks of the Badshot Formation and Lardeau Group near the northern end of the Kootenay arc, an arcuate, north to northwest trending belt of Paleozoic and Mesozoic strata that is now classified as a distinct, pericratonic, terrane. The arc rocks are bordered by Precambrian quartzite in the east and they young to the west, where they are bounded by Jurassic-age intrusive complexes. They were deformed during the Antler orogeny in Devonian-Mississippian time and refolded and faulted during the Columbian orogeny, in the Middle Jurassic. A large panel, the "Selkirk allochthon", was later offset to the northeast by dip-slip motion along the Columbia River Fault.
The Badshot Formation is composed of a thick Cambrian limestone that is a distinctive marker horizon in the Trout Lake area. It is underlain by Hamill Group quartzite and it is overlain by a younger assemblage of limestone, calcareous, graphitic and siliceous argillite and siltstone, sandstone, quartzite and conglomerate, and also mafic volcanic flows, tuffs and breccias, all of which belong to the Lardeau Group. The rocks are isoclinally folded and intensely deformed, but only weakly metamorphosed. They occur as intercalated beds of marble, quartzite and grey, green and black phyllite and schist. Fyles and Eastwood (EMPR BULL 45) subdivided the group into six formations (Index, Triune, Ajax, Sharon Creek, Jowett and Broadview) of which the lowermost (Index) and uppermost (Broadview) are the most widespread. The Triune (siliceous argillite), Ajax (quartzite) and Sharon Creek (siliceous argillite) are restricted to the Trout Lake area. The Jowett is a mafic volcanic unit.
Sharon Creek provides a partial cross section through the Lardeau Group. From northeast to southwest, it cuts through black siliceous argillite of the Triune Formation, massive grey quartzite of the Ajax Formation, black siliceous argillite and phyllite of the Sharon Creek formation and green phyllites of the Broadview Formation. The rocks are highly deformed and schistose. They have the regional northwest trending strike and moderately steep northeast dip found in this part of Silver Cup Ridge. The rocks are also cut by axial plane parallel shears.
The California vein is "immediately west of the head of Sharon Creek". According to Fyles and Eastwood (EMPR BULL 45), an adit was driven into a pyroclastic member of the lower Broadview Formation. The workings were inaccessible by 1962, but the dump rocks showed that it had been driven on a "cavernous" quartz-calcite vein containing pockets of massive galena.
