Nevada is now the leading gold-producing state in the nation, in 2007 producing 80% of the gold mined in the United States.Almost all the gold in Nevada comes from large open pit mining and cyanide heap leaching recovery. A number of major mining companies, such as Newmont Mining, operate gold mines in the state.Gold mining in Nevada, a state of the United States, is a major industry, and one of the largest sources of gold in the world. Nevada currently mines 79% of all the gold in the United States, which is equivalent to 5,640,000 troy ounces (175 t) in 2009. Total gold production from Nevada recorded from 1835 to 2008 totals 152,000,000 troy ounces (4,700 t), worth over US $228 billion at 2011 prices. Almost all the gold in Nevada comes from large open pit mining and cyanide heap leaching recovery. A number of major mining companies, such as Newmont Mining, Goldcorp and Barrick Gold Corporation, operate gold mines in the state.