Bingham Copper Mine
Nothing inspires a person to dig a big hole like the promise of money. This is exactly what led the owners of the Utah Copper Company to purchase a portion of Bingham Canyon, Utah, on June 4, 1903. Excavation began in earnest in 1906 when workers began using steam shovels; soon conveyer belts, trucks and trains were removing hundreds of tons of ore each day. This ore not only contained copper, but also gold, silver and molybdenum, the supply of which has yet to be exhausted. After more than 100 years of excavation, the pit-mine now measures 2.73 miles (4.4 kilometers) wide and 0.7 miles (1.2 kilometers) deep and is Earth's largest man-made excavation [source: Utah.com].
It's not just the size of the Bingham Copper Mine that makes it incredible. Since its inception, the mine has produced about 18.7 million tons of copper, making it the most productive operation of its kind in the world. The machines used to make the excavation are also pretty impressive. The electric shovels are capable of moving 98 tons of earth at one time, and weigh in at an impressive 3.2 million pounds (1.5 million kilograms). Equally remarkable are the trucks used to move the ore: They stand more than 23 feet (7 meters) tall and can carry 255 to 360 tons at a time [source: Kennecott]. Given the mine's massive machinery, don't expect excavation to slow down any time soon; officials say the mine will be at least 500 feet (152.4 meters) deeper by 2015.