Several Lower Permian limestone members of the Devonian to Permian Chilliwack Group are exposed in a section of interbedded limestone, greywacke, argillite and chert for 1600 metres along the north side of the Chilliwack River, 19 kilometres east of Vedder Crossing. An upper 120 metre thick limestone member is separated from a lower member of unknown thickness by a bed of argillite and greywacke. The limestone strikes northwest and dips 20 to 50 degrees northeast.

The two members are composed of recrystallized, medium grey limestone with some irregular masses and veinlets of white calcite and quartz. The upper member contains thin beds and lenses of black chert. A chip sample across the top 61 metres of the upper limestone member analysed 50.3 per cent CaO. 0.29 per cent MgO, 8.24 per cent insolubles, 0.44 per cent R2O3, 0.34 per cent Fe2O3, 0.005 per cent MnO, 0.022 per cent P2O5, 0.119 per cent sulphur and 40.1 per cent ignition loss (Bulletin 40, page 42).