The Bingham mine is considered the largest excavation in the world. It is over 4000 feet deep.  More than 15 million tons of copper have been produced during the excavation along with 620 tons of gold, and 5000 tons of silver dating back to 1863.  About 40 million years ago the region was intruded by a massive magma body which spread ore-rich hydrothermal fluids throughout the country rock and upper sections of the stock.  The stock that formed from the cooling of the magma is a quartz monzonite porphyry full of mineralization.  Although the stock was emplaced at great depths, erosion exposed the upper regions of mineralization.  Mining has exposed the deep sections of the stock which still contains an estimated 900 million tons of copper ore.  The visitor center is open 7 days a week.