The Greg occurrence is located on a ridge crest northeast of Wasi Creek, approximately 200 kilometres northwest of the community of Fort St. James.

The showing is located near the contact of carbonate rock (on the north) with a volcanic unit (on the south). The carbonate rock is part of a Lower Cambrian to Middle Devonian package comprising rocks of the Atan, Razorback, Echo Lake, and Otter Lakes groups consisting of limestone, dolomite, lesser shale, quartzite, and argillaceous limestone. The volcanic rocks presumably belong to the Mississippian to Permian Nina Creek Group (equivalent to the Slide Mountain Group) comprised of massive and pillowed basalt, argillite, chert, gabbro, wacke, and felsic tuff (Fieldwork 1991).

Mineralization reportedly consists of disseminated sphalerite and galena within a blackish limestone unit (probably of the Ordovician to Lower Devonian Echo Lake Group or the Middle Devonian Otter Lakes Group), at or near the contact of andesitic flows and tuffs (Assessment Report 4620; Geology and Exploration in British Columbia 1974).

In 1972, the Greg group of claims were staked following the finding of anomalous zinc and silver silt samples values in a small creek draining the area. In 1973, on behalf of Pechiney Development Ltd., a preliminary exploration program was carried out to evaluate these anomalies which consisted of geological mapping, soil (307) and rock (19) sampling, and a magnetometer survey.