Polymetallic mineralization occurs discontinuously over a 70- by 200-metre area on the west shore of Harrison Lake, 1 kilometre northwest of Five Mile Bay.

A roof pendant lies preserved along the west side of Harrison Lake at the eastern margin of the Jurassic to Tertiary Coast Plutonic Complex. The pendant comprises rhyolitic tuffs, lapilli tuffs, lahars, andesitic to dacitic flows and crystal tuffs of the Lower Cretaceous Brokenback Hill Formation, Fire Lake Group.

Mineralization consists of disseminated sphalerite and chalcopyrite with minor galena, arsenopyrite and/or pyrite in grains up to 2 centimetres in diameter. The mineralization is hosted by a rhyolitic quartz eye lapilli tuff. A sample of tuff, containing sphalerite and galena, assayed 0.9 grams per tonne silver, 0.3435 per cent zinc and 0.0393 per cent lead (Assessment Report 11358, Appendix 5, Sample 11258).