Tuul River
The gold mines of importance are the Zaamar gold mine, the Boroo hard rock gold mine (discovered and extracted since 1979 by open cast mining), Gatsuurt Gold Mine, and tracer gold extraction by the process of dredging the Tuul River. In addition to Copper, Oyu Tolgoi also has large reserves of gold, and the deposit is assessed to contain 14 million ounces of gold in addition to the 19 million tons of copper. This huge ore deposit is stated to be the second largest discovered and valued at US$46 billion at 2003 prices.