| Barry Landi | Neil Hege |
 |  |
| July 2015-February 2019 | July 2011 – July 2015 |
| Brian Bumgarner | Tim James |
 |  |
| July 2004 – June 2011 | July 1996 – June 1999 |July 2002 – June 2004 Interim Chief- February 2019-Present |
| Joe Long | Rick Boles |
 |  |
| July 1999 – June 2002 | July 1989 – June 1992 |
| Mike Hege | Bobby Weaver |
 |  |
| July 1979 – June 1989 | July 1992 – June 1996 | January 1973 – June 1975 |
| Richard Boles | Clayton Leonard |
 |  |
| January 1966 – December 1972 | July 1975 – June 1979 | April 1958 – December 1965 |