A mass of Permian limestone of the Devonian to Triassic Harper Ranch Group outcrops in 50 metre high cliffs along the crest of a ridge for 300 metres on the west side of Highway 6, 17 kilometres south-southeast of Cherryville. The limestone occurs on the historic Monashee property (082LSE001); refer to it for further information.

The limestone is bounded to the south by medium to coarse grained hornblende biotite granite of the Jurassic Nelson Intrusions and to the north by greywacke. Bedding strikes 108 degrees and dips 65 degrees south.

The limestone is medium to fine grained, medium grey to white, massive to bedded and highly jointed. Chert is quite common, occurring as rusty stringers and as 15 to 20 centimetre thick, contorted bands.

A sample of chips taken in 3-metre intervals across 60 metres at the south end of the bluffs analyzed 49.55 per cent CaO, 1.99 per cent MgO, 5.79 per cent insolubles, 1.84 per cent R2O3, 0.83 per cent Fe2O3, 0.04 per cent MnO, 0.01 per cent P2O5, 40.37 per cent ignition loss and 0.20 per cent water (Minister of Mines Annual Report 1961, page 148, Sample 12).