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 metasediment- ary 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.

In the early days an area in the lower part of Coulter Creek, where the depth to bedrock is very small, was placer mined. A little further upstream attempts were then made to tunnel on a buried channel on the south side of the creek. More recently, hydraulicking operations have taken place on a buried channel on the north side of the creek. The channel is about 10 metres above the present creek and the bedrock gravel is overlain by up to 30 metres or more of boulder clay.

"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).