When I was a young kid, in the 60's, we used to listen to Jayhawk's basketball on the radio. The announcer was Max Falkenstien. He'd already been at it for almost 20 years.
Last year, if you listened to KU basketball, the announcer was ... Max Falkenstien. He's been at it 59 years, and still going.
Previous winners include Gowdy, Chick Hearn, Marv Albert, Caywood Ledford, Bob Costas, and somebody named Vitale. Of them all, only Ledford and Falkenstien spent there entire careers associated with one school. (Oddly enough, both schools have the initials K and U, though not necessarily in that order.)
I can't find it anywhere on the web, but I seem to remember that Gowdy stopped doing college basketball after the 1971 NCAA semifinal between Kansas and UCLA, when he forgot the names of some Kansas players.