The United States Penitentiary, Administrative Maximum Facility (USP Florence ADMAX) is an American federal prison which provides a higher level of custody than a maximum security prison. It is classed as a supermax or "control unit" prison, where the safety of inmates and staff is paramount. It is located in Fremont County, Colorado and opened in 1994, and it is informally known as the "Alcatraz of the Rockies".
The Federal Bureau of Prisons needed a unit designed specifically for the secure housing of those prisoners most capable of violence toward staff or other inmates. Prisoners spend 23 hours per day in single, sound-proof cells with facilities made of poured concrete to deter self-harm, and 24-hour supervision, carried out intensively with high staff-inmate ratios. Phones are generally banned and only limited broadcast entertainment is permitted. After three years in maximum confinement, some prisoners may be transferred to a less restrictive prison. The aim is to encourage "reasonably peaceful behavior" from the most violent "career" prisoners.
The high standard of security has been noted by many, though there is some concern about the impact of extended confinement and isolation on mental health.