The station signed on-the-air on February 14, 1953 as KTTS-TV and was sister station to KTTS-AM radio. Their studios were in the
Springfield Chamber of Commerce building on the southwest corner of Walnut and Jefferson Streets downtown. By the 1960s it was under new ownership, which changed the call letters to KOLR-TV in 1970 to reflect its conversion to color as television shows and sets were moving
away from black-and-white. It also shared a secondary ABC affiliati
on with KYTV until 1968 when KMTC signed on. That station later became KOLR's sister station, Fox affiliate KSFX. In 1985, KOLR dropped the "-TV" suffix. It was acquired by the Nexstar Broadcasting Group through its Mission Broadcasting subsidiary in 2003 when Nexstar acquired Quorum Broadcasting. The station's revamped website debuted in spring 2007.
Digital television[]
It began full power, high definition broadcasting on January 19, 2007. The station originally aired its digital signal on UHF channel 52. As a result of this channel being on a UHF frequency which would no longer be in use after the June 12, 2009 cutoff date for analog television broadcasting (channels 52 to 69). On April 16, KOLR remained on channel 10 when the analog to digital conversion was completed. Its analog NTSC transmitter had an effective radiated power of 316 kilowatts which was the highest allowed for a VHF Band III transmitter. Some viewers had trouble picking up KOLR after the switch to digital. FM traps installed inbetween the antenna and AMP solved the problem for some viewers but not others. Some viewers continue to have trouble picking up the signal.
News operation[]
On April 28, 2009 the station launched an update to its graphics, music, logo, and news philosophy. KOLR has the longest-running evening anchor team in the Ozarks. During weather segments, the station uses live NOAANational Weather Service radar data from several regional sites. This is known on-air as "Live Digital Doppler".
In March 2010, KOLR/KSFX became the second station in the Ozarks and the first Nexstar-owned station to broadcasts its newscasts in 16:9 widescreen standard definition, even though the production is not in full high definition.
