The Comstock property is situated near the head of Springs Creek on the ridge between Springs and Bruce creeks, at 2560 metres elevation above sea level, in the Golden Mining Division. The property consists of a single Crown grant (Lot 4342).

Regionally, the area is underlain by Proterozoic clastic sedimentary rocks of the Purcell and Windermere supergroups and by lower Paleozoic strata of the Beaverfoot and Mount Forster formations (Geoscience Map 1995-1).

The Purcell Supergroup strata include the Aldridge, Creston, Kitchener, Dutch Creek and Mount Nelson formations. The Windermere Supergroup unconformably overlies the Purcell Supergroup rocks and includes the Toby Formation and Horsethief Creek Group (Paper 1990-1).

In the vicinity of the occurrence, rocks of the Kitchener and Dutch Creek formations have been further subdivided and assigned to the Van Creek and Gateway formations. The Van Creek Formation correlates with the Lower Kitchener Formation while the Gateway Formation is equivalent to the lower portion of the Dutch Creek Formation. The Mount Nelson Formation has been subdivided into seven discrete members, a lower quartzite, a lower dolomite, a middle dolomite, a purple dolomite, an upper middle dolomite, an upper quartzite, and an upper dolomite (Open File 1990-26).

Rocks of the Horsethief Creek Group, Beaverfoot and Mount Forster formations are folded and overthrusted by rocks of the upper portion of the Dutch Creek Formation and the lower members of the Mount Nelson Formation. The sedimentary rocks have undergone regional metamorphism to at least greenschist facies.

The deposit is within the upper dolomite member of the Mount Nelson Formation, immediately below the Windermere unconformity (Open File 1990-26). The host dolomite is light grey and fine grained with abundant black chert layers which preferentially replace cryptalgal structures and thin carbonaceous black shale interbeds. The strata are folded in northwest-trending anticlines and synclines which vary from isoclinal to more open, broader folds. The occurrence consists of a 1 metre wide massive galena vein occurring as replacement of the dolomite. A 19 tonne bulk sample taken from the vein in 1907 yielded 21,461 grams of silver and 11,189 kilograms of lead.