The Lardeau limestone occurrence is situated along a cliff on the west side of Kootenay Lake, 1.6 kilometres north of Lardeau on Highway 31, in the Slocan Mining Division.

Regionally, the area lies within the Kootenay Arc near the margins of the Ancestral North American Terrane. The Kootenay Arc is a curving belt of highly deformed metasedimentary and metavolcanic rocks which includes the Upper Proterozoic Horsethief Creek Group, the Eocambrian Hamill Group, the Lower Cambrian Badshot Formation, and the lower Paleozoic Lardeau Group. The volcano-sedimentary sequence is intruded by numerous Ordovician, Devonian and Mississippian granitoid plutons. The rocks have undergone regional metamorphism to middle or upper greenschist facies (Paper 1993-1).

A narrow band of limestone of the Lower Cambrian Badshot Formation trends northward along the west side of Kootenay Lake near its north end for 4.4 kilometres. The bed dips gently westward on the east limb of a tight, overturned antiform cored by schist of the overlying Lardeau Group and flanked by underlying quartzite and schist of the Marsh Adams Formation (Hamill Group).

A quarry at the north end of the band displays medium grained, dark bluish grey to bluish grey and white striped limestone containing some interbeds of highly siliceous limestone 5 centimetres to at least 0.6 metre thick. Quartz stringers and thin streaks of brown weathering slate are also evident. A sample comprised of chips taken at 0.6-metre intervals across a 15.2-metre section of light and dark bluish grey limestone just south of the quarry analysed 51.11 per cent CaO, 3.21 per cent MgO, 1.96 per cent SiO2, 0.27 per cent Al2O3, 0.21 per cent Fe2O3 and 0.01 per cent sulphur (CANMET Report 811, page 212, Sample 82A).

The limestone was quarried for flux for the smelter at Nelson between 1896 and 1907. The quarry is developed at the foot of a cliff formed by the limestone, 1.6 kilometres north of Lardeau. No production figures are available.