The Hyder Skookum showing is located between Skookum and Fish Creeks in southeastern Alaska.

Located in the Intermontane Belt, the area, bounded on the west by the Coast Crystalline Complex and on the east by the Bowser Basin, is part of the Stikinia Terrane.

The showing is hosted by the Upper Triassic to Lower Jurassic Hazelton Group Unuk River Formation metavolcanics. The Hazelton Group is a northwest trending, steeply east dipping belt of folded andesitic lapilli tuffs, flows and breccia containing a thick sequence of argillite and siltstone infolded along a synclinal axis. The sequence is intruded by the Early Jurassic Texas Creek plutonic suite of dacitic porphyry dykes and sills, Eocene granitic Hyder intrusives and lamprophyre dykes.

Two parallel quartz veins strike northwest and dip steeply south. Fragments of the country rock, forming a breccia with the veins, carries disseminated pyrite. The southern vein is hosted partly in a Texas Creek porphyry dyke and partly in metavolcanics, while the northern vein is wholly contained in metavolcanics. These veins are up to 2.13 metres wide and contain minor calcite.

An open cut exposed a vein mineralized with disseminated sul- phides, solid masses and veinlets in the metavolcanic country rock. The vein is 76 centimetres wide, strikes 130 degrees and dips 60 degrees south. Mineralization consists mainly of pyrrhotite with a little associated chalcopyrite and arsenopyrite.