Berkeley Pit
About
The most interesting (horrifying) feature of Butte is the 1,700-foot-deep Berkeley Pit (sometimes referred to by out-of-staters as the "Butte Hole"), the site of a former copper mining operation that is now partially filled with toxic runoff and is listed as a Superfund site. Despite the frightening description, The Pit is an interesting and instructive side trip and should not be passed up.