<P> Most United States Penitentiaries (USPs) are high - security facilities, which have highly secured perimeters with walls or reinforced fences, multiple and single - occupant cell housing, the highest staff - to - inmate ratio, and close control of inmate movement . The most notable facility in the federal prison system is Florence ADX, the federal supermax prison in Florence, Colorado, which holds inmates who are considered the most dangerous and in need of the tightest controls . USP Atlanta, USP Leavenworth, USP Lompoc, and USP Marion are medium - security facilities . USP Hazelton is in the process of adding a medium - security facility to its existing high - security unit . USP Marion contains a highly restrictive Communication Management Unit, which holds inmates under stricter controls . Many USPs include minimum - security satellite camps on the same property and under the same administration as the higher - security unit (s). </P> <P> † Includes female inmates </P> <Table> <Tr> <Th> Name </Th> <Th> Location </Th> </Tr> <Tr> <Td> Administrative United States Penitentiary, Thomson </Td> <Td> Illinois </Td> </Tr> <Tr> <Td> United States Penitentiary, Allenwood </Td> <Td> Pennsylvania </Td> </Tr> <Tr> <Td> United States Penitentiary, Atlanta </Td> <Td> Georgia </Td> </Tr> <Tr> <Td> United States Penitentiary, Atwater </Td> <Td> California </Td> </Tr> <Tr> <Td> United States Penitentiary, Big Sandy </Td> <Td> Kentucky </Td> </Tr> <Tr> <Td> United States Penitentiary, Beaumont </Td> <Td> Texas </Td> </Tr> <Tr> <Td> United States Penitentiary, Canaan </Td> <Td> Pennsylvania </Td> </Tr> <Tr> <Td> United States Penitentiary, Coleman † </Td> <Td> Florida </Td> </Tr> <Tr> <Td> United States Penitentiary, Florence ADX </Td> <Td> Colorado </Td> </Tr> <Tr> <Td> United States Penitentiary, Florence High </Td> <Td> Colorado </Td> </Tr> <Tr> <Td> United States Penitentiary, Hazelton † </Td> <Td> West Virginia </Td> </Tr> <Tr> <Td> United States Penitentiary, Lee </Td> <Td> Virginia </Td> </Tr> <Tr> <Td> United States Penitentiary, Leavenworth </Td> <Td> Kansas </Td> </Tr> <Tr> <Td> United States Penitentiary, Lewisburg </Td> <Td> Pennsylvania </Td> </Tr> <Tr> <Td> United States Penitentiary, Lompoc </Td> <Td> California </Td> </Tr> <Tr> <Td> United States Penitentiary, Marion </Td> <Td> Illinois </Td> </Tr> <Tr> <Td> United States Penitentiary, McCreary </Td> <Td> Kentucky </Td> </Tr> <Tr> <Td> United States Penitentiary, Pollock </Td> <Td> Louisiana </Td> </Tr> <Tr> <Td> United States Penitentiary, Terre Haute </Td> <Td> Indiana </Td> </Tr> <Tr> <Td> United States Penitentiary, Tucson </Td> <Td> Arizona </Td> </Tr> <Tr> <Td> United States Penitentiary, Victorville </Td> <Td> California </Td> </Tr> </Table> <Tr> <Th> Name </Th> <Th> Location </Th> </Tr>

How many federal penitentiaries are there in the united states
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