The Charleston past producer lies on the west side of Whitewater Creek, 1 kilometre north of the Whitewater occurrence (MINFILE 082KSW033) and 1.75 kilometres north of Retallack, British Columbia.
Regionally, the area lies on the western margin of the Kootenay Arc, in allochthonous rocks of the Quesnel terrane. In the vicinity of the occurrence, the Quesnel terrane is dominated by the Upper Triassic Slocan Group, a thick sequence of deformed and metamorphosed shale, argillite, siltstone, quartzite and minor limestone. Rocks of the Slocan Group are tightly and disharmonically folded. Early minor folds are tight to isoclinal with moderate east-plunging, southeast-inclined axial planes and younger folds are open and southwest-plunging with subhorizontal axial planes. The sedimentary sequence has been regionally metamorphosed to lower greenschist facies. To the south, the Slocan Group has been intruded by the Middle Jurassic Nelson Intrusions, which comprise at least six texturally and compositionally distinct phases ranging from diorite to lamprophyre. The most dominant phase is a medium- to coarse-grained potassium feldspar porphyritic granite. Several feldspar porphyritic granodiorite dikes, apparently related to the Nelson Intrusions, also cut the sedimentary sequence near the occurrence. Volcanic rocks of the Permian to Carboniferous Kaslo Group are exposed to the west (Paper 1989-5).
Locally, three well-defined individual veins form the Charleston occurrence: one vein on each of the Charleston, Keystone and Colorado Crown grants. The veins are hosted in shear and fissure zones concordant to slightly discordant with the hostrocks. Black slate interbedded with narrow bands of limestone host lithologies of the Triassic Slocan Group. Narrow bands of quartzite and massive argillaceous slate occur occasionally. The Charleston vein was developed over 5 levels, 200 metres horizontal distance and 105 metres along strike of the vein. The veins vary from 5 to 50 or more centimetres wide, and contain shoots of zinc-lead-silver ore. Sphalerite is the most abundant sulphide and is locally associated with argentiferous tetrahedrite. Galena is irregularly distributed throughout the ore. Quartz and siderite are the main gangue minerals and veins frequently contain abundant brecciated wallrock.
In 1986, a 1.2-metre wide oreshoot was found 90 metres from the portal of the No. 5 adit, on the Charleston vein. Ore consisted of a mixture of galena, sphalerite and tetrahedrite in a gangue of quartz, siderite and brecciated wallrock over 46 metres strike length. Until 1935, the Charleston vein received the majority of work, although some important mineralization had been reported on the Keystone vein.
The Keystone vein is located 365 to 460 metres south of the Charleston vein and was explored by two adits. Mineralization in the Keystone vein consists of sphalerite with lesser galena and pyrite hosted in siderite, calcite and brecciated wallrock.
The Colorado vein, 260 metres from the Keystone vein, is reported to have yielded some rich silver ore. Some samples carried lumps of tetrahedrite, sphalerite, galena and pyrite associated within stringers of quartz, siderite and calcite. The Colorado vein strikes 115 degrees and dips 55 degrees to the southwest. The vein has been traced along strike to the west for approximately 135 metres.
Intermittent production from the Charleston mine spans 68 years from 1898 to 1966. A total of 2324 tonnes is reported to have yielded 1 038 623 grams silver, 155 grams gold, 390 kilograms cadmium, 80 871 kilograms lead and 87 444 kilograms zinc.
Underground development of the Charleston occurrence began in 1894 on the Charleston Crown grant (Lot 2091). The Colorado Crown grant (Lot 1476) was added to the Charleston Group in 1898; in 1899, the Keystone Crown grant (Lot 2179) was also added to the group. Very little work was done on these claims between 1898 and 1914. A.J. Harris acquired a lease on the property in 1914 and carried out small development work; he became the owner of the property later that year. The property was held by the Keystone Development Co., the Charleston Silver Mines Co. and the Northern Trust Co. during 1920 to 1923. Operations were returned to Harris in 1924. In 1926, E.J. Edwards of Seattle optioned the property. The Keystone Charleston Mining Co. was formed to operate the mine in 1928, with operations ceasing in the following year. The property was intermittently worked by Harris in 1930, 1938 and 1939 and otherwise lay idle until 1946, when the Slocan Charleston Mining Co. Ltd. purchased the property. The underground workings were reopened and production occurred in 1950, 1951 and 1955. Buchanan Mines Ltd. began exploration on the property in 1965. Surface trenching is reported to have uncovered a new vein. Production is reported for this and the following year.
In 1965 to 1967, Buchanan Mines Ltd. conducted trenching and induced polarization surveys, and drilled a series of shallow vertical diamond drill holes. In 1978 and 1979, Semco Mining Corp. completed programs of geological mapping, trenching and geochemical sampling on the area. Sampling of the Colorado vein yielded up to 171 grams per tonne silver, 7.9 per cent lead, 7.3 per cent zinc, 2.1 per cent copper and 2.7 per cent antimony (Property File - Semco Mining Corp. [1979-07-01]: Preliminary Mineral Evaluation Report - Charleston-Wellington-Kaslo Claim Group).
In 1983, a diamond drill hole explored a possible extension of the Colorado lode on the Colorado claim. The drillhole intersected a very strong fault zone and an unmineralized quartz vein. Results were discouraging, with the highest geochemical results (Sample 3316) yielding 2.3 parts per million silver, 500 parts per million lead and 250 parts per million zinc over the interval 34.0 to 36.0 metres (Assessment Report 11222).
In 1989, Doron Explorations Inc. optioned the property and conducted sampling and trenching. In 1993, the area was examined by Slocan-Charleston Mining Co. Ltd. A dump sample from the Keystone tailings assayed 174 grams per tonne silver and greater than 1 per cent each of lead and zinc (Property File - R.S. Thomson [1993-10-01]: Letters Re: Petrographic Study Compares the Whitewater Area Favorably with Sullivan Mine).