The Devon occurrence covers a prominent hill of limestone 80 metres high and 500 metres long. The site is 24 kilometres east of Vedder Crossing, on the south side of the Chilliwack River where it is joined by Chipmunk Creek. Locally the Devonian to Permian Chilliwack Group underlies the area. It is comprised of interbedded limestone, greywacke, argillite and chert. The Devon occurrence is described as fractured limestone with some chert lenses. An analysis of the limestone returned 54.89 per cent CaO recalculated to 97.98 per cent CaCO3.