Alcatraz (ălˈkətrăzˌ) [key] [Sp. Álcatraces = pelicans], rocky island in San Francisco Bay, W Calif, about one mile (1.61 km) north of San Francisco. Alcatraz was first sighted by the Spanish in 1772 (and possibly three years earlier). Its name derives from the presence of a pelican colony, but Spanish and Mexican maps referred to Yerba Buena Island as Alcatraz until 1826, when the two islands clearly acquired their present names.
Alcatraz came under U.S. control in 1850 and became the site of the first U.S. fort on the West Coast. It was used as a U.S. military prison from 1859 until 1934, when it became a federal prison housing the most dangerous criminals; it was closed in 1963. Nicknamed "The Rock," it was a symbol of the impregnable fortress prison with maximum security and strict discipline.
From 1969 to 1971 a group of Native American activists occupied the island in the unsuccessful hope of establishing a center there, but the occupation contributed to the growth of Native American activism and was an impetus to the adoption of federal reforms. Alcatraz became part of Golden Gate National Recreation Area in 1972, and by the mid-1990s it was attracting almost a million visitors a year.
See study by E. N. Thompson (1979); D. Ward, Alcatraz: The Gangster Years (2009).