Hoover Dam Sawyers Original #11  and gaf edition of Nevada A1551

Hoover Dam ( 36°0′56″N, 114°44′16″W), also known as Boulder Dam, is a concrete gravity-arch dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Arizona and Nevada. The dam, located 48 km (30 miles) southeast of Las Vegas, is named after Herbert Hoover, who played an instrumental role in its construction, first as Secretary of Commerce and then later as President of the United States. Construction began in 1931 and was completed in 1935, over two years ahead of schedule. The dam and the power plant are operated by the Bureau of Reclamation of the U.S. Department of the Interior. Listed on the National Register of Historic Places in 1981, Hoover Dam was designated a National Historic Landmark in 1985. Lake Mead is the reservoir created behind the dam, named after Elwood Mead, who oversaw the construction of the dam.