The department currently operates 12 adult prisons (10 male institutions and 2 female institutions).[1] The department confines nearly 13,000 offenders in these facilities, with each varying in size and mission across the state.[1]
McNeil Island was opened in 1875 by the U.S. government as a federal penitentiary. WSDOC signed a lease in 1981 to use the island, which was officially deeded to the State of Washington in 1984.[5]