Various exposures of limestone of the Lower Paleozoic Sicamous Formation (Mount Ida Assemblage (Group)) occur on the west bank of the Shuswap River (Sicamous Narrows) just west of Sicamous. The limestone strikes northwest and dips northeast.

The limestone displays thin, grey and white platy bands with pods and lenses of quartz up to 0.2 metre thick. Graphite and mica occur along the partings. The limestone becomes impure and interbedded with other rocks to the west. A sample of chips taken at 6.1-metre intervals along the first 274 metres of a roadcut extending southward from Highway 1, along the west bank of the Shuswap River, analysed 38.66 per cent CaO, 1.34 per cent MgO, 23.84 per cent insolubles, 2.98 per cent R2O3, 2.47 per cent Fe2O3, 0.08 per cent MnO, 0.03 per cent P2O5, 0.28 per cent sulphur and 32.21 per cent ignition loss (Minister of Mines Annual Report 1960, page 144, Sample 3).