The Anaconda occurrence is located on the east shore of Atlin Lake about 1 kilometre south of the community of Atlin.
The showing consists of a narrow quartz vein less than 25 centimetres wide hosted in variable altered upper Mississippian to Permian ultramafic peridotites (Cache Creek Complex). Serpentine alteration is common. The ultramafic ophiolite "slice" occurs within the upper Mississippian to Permian Nakina Formation of the Cache Creek Complex. The showing is interpreted to be in the hangingwall of the Monarch Mountain thrust.
The vein itself has some associated iron-magnesium carbonate alteration with sporadically pervasive magnesite; some fuchsite is also present. Some breccia and open-space textures are present. Disseminated to poddy galena and pyrite are present but minor. There is also trace disseminated black crystals of tetrahedrite or possibly chromite. The vein is narrow, vertical, and strikes at 100 degrees. An adit (ca. 1898-99) was driven along this vein. Oxidized seams and cavities are reported to have had the highest gold values, although assays are available from only one sample which reported "a small amount of gold and 0.75 ounces to the tonne silver (26 grams per tonne)".
South of the adit on the same property is a well exposed porphyritic quartz-feldspar rhyolite dike with evenly disseminated grains of pyrite which make up 5 to 10 per cent of the rock. The dike orientation is irregular, possibly due to faulting. Samples from this dike were taken but assays are not available.
An analysis of the alteration zone surrounding the vein indicated about 21.7 per cent magnesia, 27 per cent carbonic acid, 45.7 per cent silica, 5.1 per cent iron and 0.5 per cent loss on ignition and water (Geological Survey of Canada Annual Report 1899).
Work on the quartz veins started in 1898 or 1899 and a 30-metre adit was driven from a level five metres above the lake. The claim was Crown granted in 1900 but work was suspended in that year.
Homestake Mineral Development Company re-opened the property for work in 1987 and completed 13.5 kilometres of flagged grid, detailed geological mapping and lithogeochemical sampling; 160 samples were collected and sent for analysis. Total field magnetic, vertical gradient magnetic and VLF-EM surveys were also completed over 12.3 kilometres of grid.
