As of 2022, it had a bed capacity of 340 and the daily average number of resident inmates was 320.

[1] Castlerea was established as part of the system of district mental hospitals in 1939.

Operating intermittently as a tuberculosis sanitorium, it continued to function as a hospital until 1994 when it was closed.

From 1996 it opened as a prison accepting a small intake of inmates that year.

Construction work on the main cell blocks of the prison was completed in 1998.