The Homestake Mine is a historic gold mine located in Lead, South Dakota. It was discovered in 1876 and became one of the largest and deepest gold mines in North America. The mine operated for over a century, producing more than 40 million ounces of gold before its closure in 2002. After its closure, the site was repurposed for scientific research. The Homestake Mine is now home to the Homestake Underground Physics Laboratory, which conducts experiments in particle physics and astrophysics. The mine's deep tunnels provide a unique environment for studying cosmic rays and other phenomena.