The State of Montana underground past producer is located at the headwaters of the Klehini River. This occurrence is skarn hosted.
Light grey marble and brown-weathering feldspathic and micaceous quartzite of probable Devonian to Upper Triassic age strike east to northeast and dip steeply north. The sediments are intruded by a fine-grained diorite body. An irregular skarn band from 2 to 18 metres wide trends subparallel to the sediments near the upper part of the marble unit. Mineralization, occurring mainly in yellow- green garnet skarn, consists of disseminated to massive sulphide lenses which occur intermittently for 21 metres and range in thickness from several centimetres to 0.45 metres and is developed along the northwestern margin of a carbonate body. Mineralization consists of bornite, chalcocite, black sphalerite, and minor wittichenite. A grab sample from the adit dump assayed 2622.9 grams per tonne silver, 4.59 per cent copper, 0.69 grams per tonne gold, and 0.92 per cent bismuth.
A small prospect pit is located approximately 200 metres south, where altered and bleached amphibolite with 5 to 10 per cent disseminated sulphides assays 1 per cent silver, 1 per cent lead and 1.4 per cent zinc.
Production from 1908 to 1909, totalled 9 tonnes, resulting in 13,778 grams per tonne silver and 2,406 kilograms copper.