The College Bowl didn't entirely disappear after leaving NBC in 1970. Instead, the national organization that created the quiz game carried on with regional & national tournaments, much like most college sports. The 1978 tournament finals were shown in syndication, and the next year, College Bowl returned to its radio roots, with Art Fleming (Jeopardy!) as host, for a 3 year run (1979-82).
In 1984, the national semi-finals & finals were presented in a primetime special, as College Bowl returned to NBC after a 14 year absence. Pat Sajak (Wheel of Fortune) takes over as host for this one, and we pick up the first game (Minnesota-Princeton) already in progress.
Unfortunately, NBC wasn't interested in doing this again on a full-time basis. They're still doing tournaments on an annual basis, and you'd think that a cable outlet would pick up College Bowl, just because.