It is a grandfatheredClass C station, legally able to broadcast at 100,000 watts, more than any other FM station in Portland. (FCC rules do not allow new Class C licenses to be issued in Zone I, which Portland is in.)
In the movie City Slickers, Billy Crystal's character claimed to have been a sales executive for the fictional station "WBLM Radio".
History
WBLM signed on the air in 1973 on 107.5 MHz. It played so-called Beautiful Music (elevator music) from 6 AM to 6 PM and free-form progressive rock from 6 PM to 6 AM. In February 1990 it switched frequencies and call letters with 102.9 WTHT. 102.9-was previously beautiful music station WGAN-FM from 1966 until 1985. Prior to that 102.9 was WLOB-FM (The 107.5 frequency is now WFNK, the WTHT calls are currently on 99.9.)