The Berkeley Pit is a former open pit copper mine in the western United States, located in Butte, Montana. It is one mile (1.6 km) long by one-half mile (800 m) wide, with an approximate depth of 1,780 feet (540 m). It is filled to a depth of about 900 feet (270 m) with water that is heavily acidic, about the acidity of Coca-Cola, lemon juice, or gastric acid. As a result, the pit is laden with heavy metals and dangerous chemicals that leach from the rock, including copper, arsenic, cadmium, zinc, and sulfuric acid.
Berkeley Pit (center) and Yankee Doodle Tailings Pond (upper left) with terraced levels/access roadways. The city of Butte is at lower right.
The Berkeley Pit in May 1984.
Composite Fisheye View of the Berkeley Pit, April 2005
Perspective: Power line poles descending the walls of the pit. The poles are located slightly to the right of center in the above Composite Fisheye View, April 2005.
Butte is a consolidated city-county and the county seat of Silver Bow County, Montana, United States. In 1977, the city and county governments consolidated to form the sole entity of Butte-Silver Bow. The city covers 718 square miles (1,860 km2), and, according to the 2020 census, has a population of 34,494, making it Montana's fifth-largest city. It is served by Bert Mooney Airport with airport code BTM.
Butte courthouse and additional buildings, 1885
Columbia Gardens, an amusement park in Butte, c. 1905
Frank Little, an IWW organizer who was lynched in Butte in 1917
Patrons at a matinee of The Phantom Foe at the American Theater, December 25, 1920
