The Homestake mine was a deep underground gold mine located in Lead, South Dakota. Until it closed in 2001 it was the largest and deepest gold mine in North America. The mine produced more than 40 million troy ounces of gold during its lifetime. The Homestake deposit was discovered by Fred and Moses Manuel, Alex Engh, and Hank Harney in April 1876, during the Black Hills Gold Rush. By 1975, mining operations had reached the 6,800 foot level, with plans to go to 8,000 feet. The Homestake mine ceased production at the end of 2001. Reasons included low gold prices, poor ore quality, and high costs. On July 10, 2007, the mine was selected by the National Science Foundation as the location for the Deep Underground Science and Engineering Laboratory (DUSEL). It is now operated as the Sanford Underground Research Facility (SURF).
Homestake Mine gold ore, town of Lead, northern Black Hills, western South Dakota by James St. John at Wikimedia