Dolomite was quarried 3.2 kilometres west-northwest of the town of Bull River, just northeast of the Kootenay River. The Bull River quarry is developed in thickly bedded (greater than 3 metres) carbonates of the Mississippian Rundle Group, striking 025 to 030 degrees and dipping 25 degrees southeast. These beds are quite variable in composition. They consist mostly of medium-grained, granular, flesh grey dolomite with some fine-grained, siliceous material.

A narrow railway cut, 1900 metres southeast of the quarry, exposes a section of carbonate beds striking 135 degrees and dipping 20 degrees northeast. The section is comprised of a 7.3 metre thick bed of coarse-grained, grey, magnesian limestone (bed 1) underlain by 5.2 metres of earthy, crumbly weathering magnesian limestone (bed 2). This bed is in turn underlain by a 3.7 metre thick bed of medium to coarse-grained, high calcium limestone (bed 3) followed by brown magnesian limestone (bed 4). A series of samples taken across the four beds analyzed as follows (in per cent) (CANMET Report 811, page 202 Samples 70, 70A to 70C):

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Width CaO MgO SiO2 Al2O3 Fe2O3 Sulphur

(m)

Bed 1 7.3 46.87 7.66 0.54 0.20 0.16 trace

Bed 2 5.2 38.65 13.71 1.92 0.24 0.26 trace

Bed 3 3.4 54.98 0.48 0.48 0.02 0.18 trace

Bed 4 - 47.11 7.07 1.28 0.02 0.18 trace

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The dolomite quarry was operated by Cominco Ltd. between 1960 and 1962 to supply the company's iron reduction plant at Kimberley with dolomitic flux. A total of 17,835 tonnes of dolomite were quarried.