Placer gold deposits of the Quesnel Highland region, including the former rich producers of the Barkerville Camp, have accounted for a large proportion of British Columbia's alluvial gold production. With the exception of a few producers in the Wingdam area, which are underlain by Upper Triassic sediments correlative with the Nicola Group, almost all the deposits are underlain by the Upper Proterozoic to Lower Paleozoic Snowshoe Group. These predominantly metasedimentary rocks have been metamorphosed to greenschist facies.

Placer gold deposits in the region are generally found in relatively young Pleistocene gravels. The morphology and mineral associations of the gold suggests that it was derived locally, the most obvious sources are the numerous auriferous veins in the Downey succession of the Snowshoe Group.

A small amount of placer gold production is recorded for McArthur Gulch, located about 2 kilometres east of Wells. Most of the production was apparently from hydraulicking. Recorded production between 1936-45 totalled 591 grams gold (Bulletin 28).

"Data from the Cariboo mining district indicate that supergene leaching of gold dispersed within massive sulphides by Tertiary deep weathering followed by Cenozoic erosion is the most likely explanation for the occurrence of coarse gold nuggets in Quaternary sediments" (Exploration in British Columbia 1989, page 147).