The Monroe (Soab) occurrence is located in the northern head waters of the Bull River, approximately 3 kilometres south of Munroe Lake.
The area is underlain by limestone, marble and calcareous sedimentary rocks of the Upper Devonian Palliser Formation.
Locally, a distinctive carbonate rock termed "zebra facies", characterized by fenestral (and geopetal) spar dolomite crescents in a fine-grained granular dolomite matrix, hosts strata-bound lead-zinc mineralization. It is interpreted to be of supra-tidal algal origin and is underlain and overlain by massive, sub-tidal limestone. Pale- yellow to almost clear sphalerite is disseminated through the granular dolomite and is concentrated along the periphery of spar dolomite patches. The mineralization is confined to a number of discrete zones generally less than 1 metre thick and a few metres long that have been exposed by trenching over 92 metres.
Chip samples are reported to have assayed approximately 2 per cent zinc over 2.1 metres, while grab samples have yielded up to 10 per cent zinc (Property File - C. Graf [1977-11-01]: Graf Lead-Zinc Reconnaissance - Southern Rocky Mountain - Volume I).
In 1977, Riocanex completed a regional program of geologic mapping, silt sampling and prospecting on the area.