Initial exploration activity in the vicinity of the Prosperity deposit was undertaken by prospectors in the early 1930's. In 1963-64, Phelps Dodge conducted a small exploration drilling program. Taseko acquired the property in 1969 and exploration drilling continued in the 1970's and 1980's under option agreements with several mining companies. Hunter Dickinson acquired Taseko in 1991 and proceeded with extensive drilling, engineering, metallurgical and socioeconomic programs. The work carried out in the 1990's succeeded in delineating a bulk tonnage porphyry gold-copper mineral resource at Prosperity. By 1998, Taseko had advanced the project to the pre-feasibility and feasibility stages. However, in 2000 prevailing metal prices - copper price ranging from US$0.60 - $0.80 per pound and gold price ranging from US$250-300 per ounce - and a poor outlook for price performance resulted in the decision to put the project on hold.
In 2006, with gold and copper prices strengthening, Taseko re-started work on the project. A feasibility study was completed in 2007 and in 2009, using metal prices that better reflected a bullish outlook for gold and copper, Prosperity's mineral reserves were doubled.
2010 marked the culmination of a rigorous Federal and Provincial government review process for Prosperity. The development application - based upon years of third party scientific analyses - was reviewed under both the British Columbia and Canadian Environmental Assessment Acts.
Following these reviews, the Province of British Columbia granted Taseko the right to proceed with development, however, the Federal Government decided the project could not be justified as proposed and invited Taseko to submit a new design to address their concerns.
Both the Federal and Provincial Governments concluded in 2010 that the Prosperity Gold-Copper Project was not likely to have any significant adverse effects on: air quality, surface or groundwater quality, wildlife, vegetation, including old growth forest, grasslands and wetlands, fish in the Taseko river, water quality in Onion Lake, human health, traffic, biodiversity, noise emissions, archaeological resources, or mule deer and moose habitat.