High Quality Content by WIKIPEDIA articles! The Oklahoma State Penitentiary (OSP) is located in McAlester, Oklahoma, on 1,556 acres (6.30 km2). It is a prison of the Oklahoma Department of Corrections. Opened in 1908 with 50 inmates in makeshift facilities, today the prison holds more than 1,200 male offenders, the vast majority of which are maximum-security inmates. OSP is also the site of Oklahoma`s death row for men and execution chamber.