The Monashee deposit is located 20 kilometres south of Cherryville, approximately 3 kilometres north of the north end of McIntyre Lake on the east side of Monashee Pass.
The area is underlain by Devonian to Triassic metavolcanics and metasediments of the Harper Ranch Group and is a short distance north of the contact with Jurassic granitic rocks of the Nelson Intrusions, which consist of interdigitating lenses of fine- grained, altered volcanics and metasediments. The volcanics are possibly meta-andesites and the metasediments consist of argillites and marbles. The sediments strike west to northwest and dip steeply to moderately north. On the northern part of the property the Monashee Pass marble showing (MINFILE 082LSE049) forms 50 metre cliffs along the crest of the ridge overlooking Highway 6.
The intrusive rocks consist of medium- to coarse-grained, leucocratic hornblende biotite granodiorite. The generally fractured granitic rocks are locally heavily sheared and altered. The degree of kaolinization and chloritization is relative to the degree of deformation. The contact with the metamorphic rocks trends northwest.
Disseminated pyrite is common along or near the contact with the granites and is associated with fracturing in silicified and rusty metavolcanics and sediments. Pyritized rusty skarn zones, lensoid and less than 10 metres in extent, occur at volcanic/marble contacts exposed in roadside cuts.
Locally, four or five adits have been driven on the Withrow claim between approximately 1170 and 1250 metres elevation. The upper adit has been driven on a quartz vein that pinches and swells from 30 to 150 centimetres in width, with the widest sections near faults. The vein, traced on surface for 760 metres, strikes northeast and dips 34 degrees southeast. Mineralization consists of pyrite, galena, chalcopyrite, sphalerite, magnetite and native gold. A faulted outcrop containing a 1.8-metre wide quartz vein has been explored by adit but was not described. Just north of the vein outcrop, another adit has been driven on a second quartz vein. This vein is 2 to 10 centimetres wide, strikes southeast and may be a stringer in the hangingwall of the main vein. The veins occur in argillites and metamorphosed volcanics.
Sampling of the workings has reportedly yielded up to 49.9 grams per tonne gold and 178.9 grams per tonne silver from the third adit portal, 7.2 grams per tonne gold and 29.8 grams per tonne silver from the fifth adit portal and 17.1 grams per tonne gold from a ‘clearing’ (Property File - L. Sookochoff [1983-03-03]: Evaluation Report for Nakusp Resources Ltd. on the Monashee East Property).
In 1983, a selected grab sample (19255) of quartz vein material containing disseminated pyrite, galena and chalcopyrite from the ‘middle’ adit assayed 0.315 per cent copper, 0.71 per cent lead, 161.8 grams per tonne silver and 24.9 grams per tonne gold (Assessment Report 11789). Samples taken in 1989 from this same dump material assayed similar values (Assessment Report 19209). Samples of dump material from the other adits assayed insignificant values. Geochemical sampling indicated a gold anomaly in the area of the old dumps and workings on the Withrow claim.
In 1939 and 1940, 2193 tonnes of ore were milled producing 11 ,415 grams of gold, 50 ,916 grams of silver, 706 kilograms of lead and 190 kilograms of zinc.
Work was initially reported in 1886 but it may have begun earlier. Underground development and stockpiling of ore were carried out each year. The Riske (Lot 192), Vernon (Lot 193), McIntyre (Lot 194) and Riske (Lot 195) claims were Crown granted in 1887; the Withrow (Lot 306) claim was Crown granted in 1890. The stamp mill was completed in and the workings were composed of three adits: an upper adit at 1265 metres, driven 91 metres; a middle adit driven 10.7 metres; and a lower adit near the bottom of the hill driven 82.3 metres.
In 1900, the Cherry Creek Gold Mining Co. Ltd. acquired the property and the adjoining McPhail (MINFILE 082LSE009) property. Drifting and crosscutting were done in the old adits. A 5-stamp mill operated for a short time in 1903. In 1907, the Fire Valley Gold Mining Co. Ltd. acquired the two properties. The old adits were reopened but no work was reported and the company ceased work in 1915. The Progressive Mining Co. Ltd. acquired the McIntyre, Morning Sun and Monashee claims in 1921. The adit and open-cuts on the McIntyre were cleaned out. On the Morning Sun claim, a crosscut adit was driven 12 metres. On the Monashee claim, the old lower adit was reopened. In the 1920s, New Monashee Mines Ltd. acquired the Withrow, Field, Vernon and Riske claims but no work was reported.
In 1933, Monashee Mines Syndicate Ltd. acquired the Withrow, Vernon, Field and Riske Crown grants and the adjoining McPhail property. The old adits were reopened, a drift adit was extended 230 metres and two new drift adits were completed. A total of 1254 metres of drifting and raising was done by Vidette Gold before work ceased in 1935. In 1939, Monashee Development installed a 50 ton-per-day mill, which began operation in October. The mill operated for 55 days before work ceased; all equipment was removed. In 1940, the property was leased to G.M.F. and F.H. Paterson, S. Flodstrom and William McLaren, who mined remnants of ore by hand steel methods.
In 1983, reconnaissance geochemical sampling and geological mapping surveys were done on the Monashee and McPhail properties and the Moonbeam claims by I.M. Watson and Associates Ltd. for Nakusp Resources Ltd. In 1989, reconnaissance mapping and geochemical sampling was completed on the Monashee and McPhail properties, which were staked as the Kettle 2 and 1 claims, respectively. In 1992, Cameco Corp. conducted geochemical and geological surveys in the area.