Homestake Mine

The Homestake Mine pit in Lead, South Dakota

Typical auriferous greenschist gold ore from the Homestake Mine. Two small masses of native gold (Au) are visible near the bottom right.

The Homestake Mine was a deep underground gold mine located in Lead, South Dakota. Until it closed in 2002 it was the largest and deepest gold mine in North America. The mine produced more than forty million troy ounces (43,900,000 oz; 1,240,000 kg) of gold during its lifetime.^[1] This is about 70.75 m³ or a volume of gold roughly equal to 18 677 gallons (a cube with each side being roughly 4.14 metres).

The Homestake Mine is famous in scientific circles because of the work of a deep underground laboratory that was set up there in the mid-1960s. This was the site where the solar neutrino problem was first discovered, in what is known as the Homestake Experiment. Raymond Davis Jr. conducted this experiment in the mid-1960s, which was the first to observe solar neutrinos.

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).^[2] It won over several candidates, including the Henderson Mine near Empire, Colorado.

^ Yarrow, Andrew L. (August 9, 1987). "Beneath South Dakota's Black Hills". The New York Times. Retrieved 2008-01-11. Homestake, which is the largest, deepest and most productive gold mine in North America, has yielded more than $1 billion in gold over the years.
^ "Team Selected for the Proposed Design of the Deep Underground Science and Engineering Laboratory" (Press release). The National Science Foundation. July 10, 2007. Retrieved 2010-02-23.