The USGS released 3 annual reports on Active Metal and Industrial Mineral Underground Mines in the United States, for the years 2007, 2008, and 2009. No mines are reported in Arizona.
According to the latest report, "Total domestic mining and waste removal for nonfuel mineral materials production at underground operations was 138 million metric tons (Mt) in 2009. Crude ore mined at these underground operations was 136 Mt. The balance was waste removed, including ore and waste from development. Total underground mining for industrial minerals amounted to 123 Mt, nearly all of which was crude ore. Underground mining for metal ores and waste removal amounted to 15 Mt, of which 90% was crude ore."
Buried Treasure – Matt Wedel
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