The area is underlain by andesitic volcanics of the Lower Jurassic Bonanza Group and minor sediments of the Lower Cretaceous Queen Charlotte Group, Longarm Formation.

Several small showings of chalcopyrite and pyrite are found on the old KW group of claims from Hushamu Creek and west to Clesklagh Creek.

Also, a 30 centimetre wide coal seam is located within the Lower Cretaceous Longarm Formation on the old KW 89 claim. This is part of the Koskeemo coal area (refer to 092L 095).