The Southwest is the United States’ richest storehouse of metals and industrial minerals and is likely to remain so for many years. Arizona ranked first in mineral production in the US in 2005 with a production value of $4.73 billion according to preliminary figures released by the USGS. Arizona leads the Nation in copper and molybdenum production, and ranks in the top five in gemstones, perlite, silver, zeolites, iron oxide, pumice, and sand and gravel. Additionally, Arizona produces, or has produced, zinc, lead, beryllium, vanadium, uranium, tungsten, rare earths, manganese, coal, and at least 18 varieties of industrial minerals. In 2004, Arizona accounted for 62 percent of the U.S. copper production. The copper industry has a $3.3 billion direct and indirect impact on the Arizona economy. Arizona’s three largest copper producers, Asarco Inc., BHP Copper Inc., and Phelps Dodge also produce significant amounts of molybdenum, gold, and silver as byproducts in the production of copper. Phelps Dodge’s Morenci mine produced 800 million pounds of copper in 2005, has the largest EW plant in the world, and is the world’s fifth largest mine. Exploration and