The Emma Gordon occurrence is located on the eastern shoreline of Portland Canal, just south of the mouth of Marmot River, 7.5 kilometres south of Stewart.

The area is underlain by Coast Plutonic Complex granite of the Eocene Hyder pluton locally cut by a diorite dike, near the contact with andesitic volcanics of the Lower Jurassic Hazelton Group (Unuk River Formation). The Emma Gordon showing consists of highly fractured and faulted granite with some silicification in the wallrock adjacent to major fractures. A diorite dike cuts the granite and along its contacts hosts small stringers of sphalerite, pyrite, chalcopyrite and galena. A small trial shipment to the Trail smelter in 1914 assayed 2276.19 grams per tonne silver, 0.56 per cent copper and 2.74 grams per tonne gold (Minister of Mines Annual Report 1914).