You can find a list of state correctional facilities online through a state's Department of Corrections or its Department of Criminal Justice, as seen through the example of the California Department of Corrections. These departmental websites usually provide a state map of all facilities, along with other information about the specifics of each facility.
State correctional departments provide information about their individual facilities, as shown in the California example. In addition to a map, more detailed listings offer physical addresses, mailing addresses for various purposes and department phone numbers within the facility.
Some states provide an extremely detailed breakdown of their facilities, such as provided by the Texas Department of Criminal Justice. This information includes the name of the facility, its location, the type of facility, and whether it is state-run or privately operated.
Additional links in both example states take visitors to separate pages for each facility. These provide more information specific to the prison, including its size, staffing levels and even the inmate programs offered at the prison. Although the format and functionality of websites varies from state to state, the provided information is largely consistent across all states. If the required information isn't readily visible, use the websites' search tool to find it.