United States, California

California is the third largest U.S. state in terms of area. In 2005, California's estimated population was 36,132,147, making it the most populous state in the country. Approximately 68 percent of Californians live in the greater Los Angeles and San Francisco Bay Areas.

The discovery of gold in 1848 led to the California Gold Rush, which marked the opening of the Sierra Nevada region to European-American occupation and development. What began as amateur mining with simple technologies in the early years transformed by the 1860s into large-scale mining, [Page 1821]including the excavation of mines with hydrologic operations. A federal injunction put an end to immense on-site and downstream environmental impacts of hydrologic mining during the 1890s. Mining in California, however, did not stop with the end ...