The Two Shafts occurrence is located north of the Koksilah River, near Humes Creek.

The area is underlain predominantly by bedded chert and cherty basaltic tuffs of the Mississippian to Pennsylvanian Fourth Lake Formation (formerly the Sediment-Sill Unit of Muller; Buttle Lake Group). These are overlain by limestone, bedded chert and cherty tuff of the Upper Pennsylvanian to Lower Permian Mount Mark Formation (Buttle Lake Group; formerly the Buttle Lake Formation). These Paleozoic rocks are intruded by numerous dikes of feldspar porphyritic dacite and rhyolite and part of a granodioritic stock of the Early to Middle Jurassic Island Plutonic Suite (formerly called Island Intrusions).

Locally, two shallow shafts, approximately 15 metres apart, expose a porphyritic dacite intrusive overlying basaltic tuff and chert that contains 7 to 20 per cent patchy pyrrhotite.

In 1983 through 1985, Reward Resources completed programs of prospecting, geochemical sampling and ground geophysical surveys on the Independence, Koksilah, Pacific Star and Western mineral claims. A grab sample of mineralized basaltic tuff assayed 0.178 per cent copper and 1.2 grams per tonne silver (Assessment Report 13997).

In 1986, Hollycroft Resources and Nexus Resources completed a program of geological mapping and rock sampling on the Sil claims.