Copper mining in Arizona

Copper mining in Arizona
Position of Arizona
Location
State	Arizona
Country	United States
Regulatory authority
Authority	Arizona Department of Mines and Mineral Resources
Website	http://www.admmr.state.az.us
Production
Commodity	Copper
Production	750,000 metric tons
Value	US $5.54 billion
Employees	10,300
Year	2007

Copper mining in Arizona, a state of the United States, has been a major industry since the 19th century. In 2007 Arizona was the leading copper-producing state in the US, producing 750 thousand metric tons of copper, worth a record $5.54 billion. Arizona's copper production was 60% of the total for the United States. Copper mining also produces gold and silver as byproducts. Byproduct molybdenum from copper mining makes Arizona the nation's second-largest producer of that metal. Although copper mineralization was found by the earliest Spanish explorers of Arizona, the territory was remote, and copper could seldom be profitably mined and shipped. Early Spanish, Mexican, and American prospectors searched for gold and silver (see Silver mining in Arizona), and ignored copper. It was not until the completion of the Southern Pacific Railroad in 1876 that copper became broadly economic to mine and ship to market.

All copper mining was done by underground methods until the early 20th century. After the Bingham Canyon mine in Utah successfully mined a large low-grade copper deposit from a large open pit, the same technique was applied to Arizona’s porphyry copper deposits. Arizona's first open pit copper mine opened at Ajo in 1917.

American Indians used copper minerals of the Verde district at modern-day Jerome as pigment to decorate skin and textiles. The first European to visit the area is thought to be Spanish explorer Antonio de Espejo, who found silver at a location in central Arizona in 1583. No mining resulted, and Juan de Oñate led another expedition searching for Espejo’s silver location in 1598; many claims were staked, but the expeditioners returned to Santa Fe without mining any silver, and the deposits remained unexploited.