CIM opened in San Bernardino County in 1941 on 1,700 acres of land. The California Institution for Men (CIM) is a large complex consisting of four separate facilities under the administration of one warden. Dedicated on June 21, 1941, the California Institution for Men was the first major minimum security institution built and operated in the United States. It was the State of California's third correctional institution and was constructed to relieve the overcrowded conditions of San Quentin State Prison (1852) and Folsom State Prison (1881). CIM has since increased security to meet the challenges a vastly different inmate population requires. While no longer known as "the prison without walls" CIM's Secure Level I Facility A houses the largest Level I inmate population within the California prison system. The CIM I Facility can house approximately 2,000 minimum custody level inmates at the facility.