The country rocks in the general area of this site are pelitic metasedimentary and subordinate andesitic metavolcanic (greenstone) strata of the Jurassic or older Mesozoic Hazelton Group; the Triassic Texas Creek Granodiorite, which underlies and locally intrudes the Hazelton; the Eocene Hyder Quartz Monzonite, which intrudes the Hazelton and Texas Creek rocks; and still-younger Tertiary lamprophyre dikes, which cut all the other rocks (Smith 1973, 1977; Koch, 1996).

Maas and others (1995, p. 252, 260) describe the deposits as veins, disseminations, and masses of gold-bearing pyrrhotite with associated chalcopyrite and arsenopyrite, and local sphalerite and galena. Individual mineralized zones range from about 60-450 feet wide and are located near or in shears in Hazelton volcanic rocks (greenstone). The prospects roughly align with the contact between Hazelton volcanics and Texas Creek Granodiorite, and are never more than about 1300 feet in lateral distance from the surface exposure of that contact.

The prospects have been explored by small pits and trenches; there is a flooded shaft on Shaft Creek Copper prospect.