Copper mine. This is the copper pit mine at Bingham Canyon, Utah, USA. It is an opencast mine, where the land's upper layers have been stripped away to access ores found below the surface. The stepped layers, carrying roads, show the progressive excavation. There was a mountain on this site when mining began, from around 1863. From 1906, large-scale opencast mining began, and by the 1930s the mountain was reduced to a pit. From 1936 onwards, the pit was mined by the Kennecott Copper Corporation. It has produced more copper than any mine in history, some 17 million tons. In 2000, the pit was some 4 kilometres wide and 1.2 kilometres deep. Photographed in 1992.