The nature and status of mineral resources and mining in the United States have changed dramatically since the U.S. Geological Survey (USGS) was founded in 1879. At the beginning of the 21^st century, the United States is one of the largest mineral producers in the world (see Table 1.1). The United States is generously endowed with mineral resources. Spanning diverse geologic terrains, this country hosts an enormous range of mineral deposit types (Ashley, 1991; Tooker, 1991; Brobst, 1991). Metals from aluminum to zinc and nonmetals from construction aggregate to specialty clay minerals are illustrative of this mineral resource endowment. Mining of sand, gravel, or crushed stone for construction aggregate takes place in all 50 states; mining of other commodities is widespread.

Today the United States is one of the world’s largest consumers of many mineral products. The average American born in 2001, with a lifespan of 76.9 years, will need the mining of 3.6 million pounds of minerals, metals, and fuels to maintain his or her standard of living during their lifetime—averaging 47,122 pounds of new mineral and energy resources every year for each American (see Figure 1.1). The value of processed materials of mineral origin produced in the United States in 2000 has been estimated to be $374 billion (USGS, 2002a). However, the $39.4 billion value of the nonfuel minerals mined in this country in 2000 (Smith, 2002) was less than one-half percent of the U.S. gross domestic product. The