The American Correctional Association offers a directory of state prisons on its site. The National Jail and Detention Directory contains descriptions and contact information for all state prisons in the United States.
The National Jail and Detention Directory includes information about inmate programs, expenditures, capacities, other statistics, and ways to contact the facilities' administrative staff, notes the ACA. This directory is a physical book sold by the ACA.
State government websites may also contain directories of their states' prisons. For example, the Executive Office of Public Safety and Security in Massachusetts maintains a directory of state facilities on its site.