The station signed on the air on August 17, 1953 as KMMT and aired an analog signal on VHF channel 6. Its first owners were local businessmen Martin Busted, Harry Smith, and Palmer Ulland, who also owned KAUS radio (AM 1480 and FM 99.9). Originally, the station was a primary CBS affiliate with secondary ABC and DuMontrelations. After KGLO-TV (now KIMT) launched from Mason City in late 1954, KMMT switched its primary affiliation to ABC. DuMont would eventually be dropped in 1956 after that network shut down operations. This station is the longest-tenured ABC affiliate in the Upper Midwest.