South Dakota & Dark Matter

I think your talking about Homestake mine that is about 8,000' deep. I know some folks from Deadwood their family worked the mine for years before it closed.



Homestake Through 2001, the mine produced 39.8 million ounces of gold and 9 million ounces of silver.[citation needed] In terms of total production, the Lead mining district, of which the Homestake mine is the only producer was the second-largest gold producer in the United States, after the Carlin district in Nevada."

That sounds like the mine! My sister was telling me about it, she lives in Near Rapid City and sent me the article. Can't remember the East coast university that is also involved.