The Fog occurrence is located approximately 2 kilometres north-northwestof Mount Carruthers.

The regional geology is similar to that of the Carruthers Creek occurrence (refer to 094D 060). The occurrence is hosted in sedimentary rock of the Upper Triassic Dewar Formation (Takla Group), near a contact with Lower Jurassic volcanic rocks of the Telkwa Formation (Hazelton Group). Chalcocite and bornite, with minor amounts of native copper and malachite, were reported as disseminations within a grey to black shale unit (see Lake (094D 108)

In 1996, it was reported that the primary mineralized bed is a sandstone layer ranging from 0.3 to 3.0 metres in thickness and has been traced approximately 200 metres in strike where it runs beneath a talus slope. Copper mineralization, consisting of chalcocite, bornite, and malachite was identified in andesitic rock at the northern end of the claims. This mineralization, located in a snow slide area where the bedrock is exposed, is approximately ten metres by three metres in dimension. While several rock samples have been collected previously, six samples were collected in the sedimentary beds located in the cirque during this trip. A 1.5-metre sample graded 4.38 per cent copper and 8.4 grams per tonne silver (Sample 92265, Assessment Report 25586). Sample Cu1 from 1976, which assayed 2.83 per cent copper, is located in the Fog claim area, possibly to the west or northwest (Figure 2, Assessment Report 18175).

In 1976, Robert M. Tait conducted a prospecting program on his North and Lake claims about 1.75 kilometres north of Mount Carruthers (Assessment Report 5927). Chalcocite, bornite, native copper and chrysocolla were located along an east-southeast trend on the south half of the Lake claim, over about 500 metres. Location of claims and mineralization was vague. No assays were reported.

In 1988, Mr. Tait conducted another prospecting program on his 5-unit Car 1 to 5 claims. Sample Cu3 was taken about 1.2 kilometre east from Caruthers Creek, to the north-south trending ridge, about 1.9 kilometres north of Mount Carruthers. Sample Cu3 was collected several hundred metres east-southeast of the Car claim group. It is not clear if sample Cu3 was collected in the area of the copper mineralization reported by Mr. Tait in 1976.

In 1997, Robert Tait visited the Fog claim with geologist Jim Miller-Tait. Six rock samples were collected for analysis (Assessment Report 25586).