A report on the environmental geology of Butte,
Montana with a focus on Berkeley Pit. Produced by Jason Von-Kundra. For More Information: Pit Watch 2009.
Berkeley Pit Public Education Committee
The Berkeley Pit is a former open pit copper mine located in Butte, Montana, USA. It is one mile long by half a mile 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 (2.5 pH level). The pit is laden with heavy metals and dangerous chemicals, including arsenic, cadmium, zinc, and sulfuric acid.
The mine was opened in 1955 and operated by Anaconda Copper and later by the Atlantic Richfield Company (ARCO), until its closure in 1982. When the pit was closed, the water pumps at the bottom were removed, and groundwater from the surrounding aquifers began to slowly fill the pit. Since the pit closure in 1982, the level has risen to within 150 feet of the natural groundwater level.
The pit is currently a tourist attraction, with an adjacent gift shop. A $2
admission fee is charged to go out on the viewing platform.
Open Pit Mining
Open-pit mining, also known as open-cast mining, open-cut mining, and strip mining, refers to a method of extracting rock or minerals from the earth by their removal from an open pit or borrow.
Open pit mining.
Interactive Satellite Map
Explore the Berkeley Pit, Butte, Montana. Click
a placemark. To Pan: click and drag
or take advantage of the pan and zoom bars.