The Iron King claim is underlain by Lower Jurassic Hazelton Group volcanics of the Telkwa Formation comprised mainly of massive andesite, rhyolite, andesitic flows, intercalated tuff, breccia and massive tuff. The volcanics are intruded by a Late Cretaceous to Early Tertiary granodiorite stock and associated quartz-feldspar porphyry dikes.

An open cut on the claim exposed stringers carrying arsenopyrite, sphalerite, and chalcopyrite across a width of approximately 2.5 metres. The general strike is 054 degrees with a southeast dip. A selected sample assayed trace gold, 123.4 grams per tonne silver, 15.8 per cent zinc and 0.8 per cent copper (Minister of Mines Annual Report 1914, page 216).

On the adjacent Myrtle claim two stringers carry arsenopyrite and a little sphalerite. One selected sample from each vein assayed 10.3 grams per tonne gold, 78.9 grams per tonne silver, and 6.9 grams per tonne gold, 109.7 grams per tonne silver (Minister of Mines Annual Report 1914, page 216).