Most of the remaining jobs were in city and county jails or in other institutions run by local governments. Some 300 of these jails, all of them in urban areas, are large: they house over 1,000 inmates. Most correctional officers who work in jails, however, work in institutions located in rural areas with smaller inmate populations.
Source: Bureau of Labor
Statistics, U.S. Department of Labor, Occupational Outlook
Handbook, 2006-07 Edition
