The Taseko Mountain polymetallic vein showing, 1.5 kilometres east of Taseko Mountain, is within andesite breccias, lapilli tuffs, crystal tuffs, ash tuffs and minor andesitic to basaltic flows of the informally named Upper Cretaceous Powell Creek Formation.

A stock of Cretaceous to Tertiary diorite crosscuts these volcanic rocks and has produced extensive limonitic hornfelsed zones. The area of greatest interest is relatively inaccessible due to the steep terrain. Intermittent limonitic alteration is visible for more than one kilometre of cliff exposure. Boulders of altered and intensely silicified volcanic rocks immediately below a north-facing cliff contain disseminations, stockwork, and discrete veins up to 5 centimetres thick of arsenopyrite, sphalerite, chalcopyrite, and pyrite. This polymetallic mineralization occurs as northwesterly trending shear zones within a dike swarm and contains as much as 7.3 grams per tonne gold, 58.0 grams per tonne silver, and copper and zinc in excess of one per cent (Assessment Report 10674). Mineralization also occurs in northeast trending shears crosscutting the northwestern shear system, with limonite, magnetite and hematite.

The property was originally explored in 1982 by Utah Mines Ltd., who conducted an exploration program of rock and soil sampling. This was the only work completed by Utah Mines Ltd.

In 1991, Cascade Investments J.V. Ltd. staked the Taseko Mountain property and completed a 15-man-day exploration program consisting of geological mapping, sampling and prospecting. Of the 52 rock samples collected, the best samples were chip sample C-D12 which assayed 0.41 per cent zinc and 16.89 grams per tonne gold and float sample F-B01 which assayed 1.25 per cent zinc and 7.28 grams per tonne gold (Assessment Report 22160).