KRBM's roots began when Blaine Hanks was recruited by Blue Mountain Community College in 1968 to start a 2-year radio broadcasting program.
On April 18, 1970, KRBM signed on the air with broadcast students operating the station and Blaine Hanks as general manager.
In June 1987 OPB moved the KRBM transmitter from Blue Mountain Community College to Warren Hill and increased power to 25 kW, covering a large portion of Eastern Oregon.
OPB programs also took over most of the schedule, leaving only Friday and Saturday evenings for local broadcasting for the students.
The studios were eventually removed from the college, and OPB partnered with KUMA to maintain the operations in Pendleton.