The Nitinat Lake - NW showing is located near the south end of Nitinat Lake on the northwest shore, 4 kilometres from the Pacific Ocean.

A mass of limestone, up to a kilometre wide, extends northeast along the shore of Nitinat Lake for 2.8 kilometres. The limestone is part of the Paleozoic and/or Mesozoic Westcoast Complex and is in fault contact with Westcoast Complex granodiorite and diorite to the northwest. The thickly-bedded limestone generally strikes 100 to 120 degrees and dips 35 to 65 degrees northeast. A few dykes intrude the limestone.

The deposit generally consists of coarse-grained, white limestone (marble) containing some fine-grained, thinly-bedded siliceous layers and a few dolomitic beds. A sample comprised of chips taken at 3 metre intervals along the shore for 229 metres contained 53.3 per cent CaO, 0.39 per cent MgO, 3.38 per cent insolubles, 0.34 per cent R2O3, 0.17 per cent Fe2O3, 0.006 per cent MnO, 0.008 per cent P2O5, 0.06 per cent sulphur and 42.3 per cent ignition loss (Bulletin 40, page 98).