Underground hard-rock mining of gold from quartz veins accounts for most of the mineral wealth extracted from the Hatcher Pass area.

[3] At Hatcher Pass proper the southwestern margin of the Cretaceous to Tertiary age Talkeetna Mountains batholith is in fault contact with a pelitic schist.

The schist to the south consists mainly of metamorphosed and deformed sedimentary rocks, of Late Cretaceous to Paleocene age.

The schist may represent subducted Valdez Group that was exhumed in the forearc region from beneath the Peninsular terrane.

Unmetamorphosed Late Cretaceous or Tertiary terrestrial sedimentary rocks of the Arkose Ridge Formations lie to the south of the schist and intrusives, across a low-angle detachment fault.

A rock unit variously mapped as intricately intermixed amphibolite and quartz diorite; or as a migmatite, occurs in contact with the Arkose Ridge formation on Government Peak and in contact with the Arkose Ridge Formation and quartz monzonite east of the Little Susitna River.

[5][6] Gold-bearing (+/- Ag, W, Sb, As, Cu, Mo, Pb, Te, Zn, Hg) veins occur in the tonalite, in small amounts in the schist, and in the Jurassic?

In its peak year, 1941, APC employed 204 men, blasted nearly a dozen miles of tunnels, and produced about 35,000 ounces of gold.