The station began life at 99.3 FM as KOSN in Thief River Falls, Minnesota in 1976. KOSN broadcast only 3,000 watts. The station changed call letters to KSNR in 1983 as it flipped to an oldies format, concentrating on 50s and 60s "Golden Oldies" format. After upgrading to 100,000 watts at 100.3 FM in 1987, the station attracted listeners in Grand Forks, North Dakota, since the signal could be heard on most radios and KSNR was the only oldies station in the area. KSNR later became "Kool 100.3", and began playing 1970s era music, and moved its studios to Grand Forks after being sold. KSNR also played Christmas music from Thanksgiving Day to Christmas Day annually until the format change in 2005. In 2000, Clear Channel Communications bought out KSNR and several other stations, and the format was changed to play 1960s and 1970s era music. It also became the flagship station for University of North Dakota basketball play-by-play broadcasts.
Kool 100.3 switched to country music as "Cat Country" in October, 2005, competing with Leighton Broadcasting's heritage country station, 97 KYCK and classic country station KNOX-FM "Rooster 94.7". In 2006, co-owned classic hits station KQHT "96.1 The Fox" began shifting towards to an oldies format. In 2005, KSNR changed its city of license from Thief River Falls to Fisher, which would allow it to move its transmitter tower closer to Grand Forks in the future. In the fall of 2012, all local personalities were removed from Cat Country in favor of Bobby Bones Show in the morning and Premium Choiceradio personalities in all other dayparts. The previous local morning show was moved to sister station KQHT, which carries an updated classic hits version of the former "Kool 100.3" oldies format. In 2016, Cat Country brought back some local personalities previously heard on the station. On October 29, 2018, it was announced that, as iHeartMedia will lose its grandfathered ownership limits in the Brunswick and Grand Forks markets as part of its bankruptcy restructuring, the company would place KSNR and WHFX into the newly formed Sun & Snow Station Trust, under the oversight of former Backyard Broadcasting CEO Barry Drake, as preparation for an eventual sale of the signals.
