One of the largest mining operations in the United States, the Mission Complex is a copper and silver mining network, with an underground mine and two open pits: the Mission pit, and the smaller, adjacent San Xavier North pit. The mine is operated by Asarco (which was purchased by Mexico's largest mining company Grupo Mexico in 1999) producing around 100,000 tons of ore a year, with an expected 510 million tons remaining. The main pit is 2.5 by 1.5 miles, and 1,000 feet deep. In 2000, Mission was the third largest copper mine in Arizona, the state that produces 65% of the nation's raw copper.