History of Arizona programs. Federal money started arriving with the Federal Emergency Relief Committee in 1930. Different agencies promoted aid to the unemployed, tuberculosis patients, transients, and illegal immigrants. The money ran out by 1931 or 1932, and conditions were bad until New Deal relief operations began on a large scale in 1933. Construction programs were important, especially Hoover Dam (originally called Boulder Dam), begun by President Herbert Hoover. It is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border with Nevada. It was constructed by the Federal Bureau of Reclamation between 1931 and 1936. It operationalized
Gold mining in the United States at the Moss mine at Oatman. In 2006, all of Arizona's gold production came as a byproduct of copper mining. Spanish prospectors found gold in the Potholes district between 1775 and 1780, along the Colorado River, in present Imperial County, California, about ten miles northeast from Yuma, Arizona. The gold was recovered from dry placers. Other placer deposits on the west bank of the Colorado River were quickly found, including the Picacho and Cargo Muchacho districts. Placer gold deposits were found at San Ysidro in San Diego County in 1828, San Francisquito Canyon and Placerita Canyon in Los Angeles County