The station first signed on the air on November 20, 1955, as CJLH-TV, broadcasting on VHF channel 7 from a 167,000-watt transmitter atop a 638-foot (194 m) tower located at what was the city limits of Lethbridge.

It was managed by CJOC's owners, Taylor Pearson & Carson, and began life as an affiliate of the Canadian Broadcasting Corporation's (CBC) television network.

Three months after CJLH went to air, measurement services showed that the station had a potential audience of 9,400 homes, but within a year, that grew to 19,200, and of those, 16,000 had bought television sets.

Local programming at the time included local newscasts; Channel 7 Spotlight, showcasing area talent; Remember When, a series of programs hosted by Harry Baalim using slides, pictures and relics to tell the history of Southern Alberta; and Home Gardener, featuring many experts in the field demonstrating proper horticultural technique.

An application from CFCN-TV in Calgary to open a repeater station in Lethbridge was unsuccessful in getting CRTC approval that year.

That same year, the station's first 2-inch black and white videotape recorder was installed, and a repeater in Brooks began operations, transmitting at low power on VHF channel 3.

It became a semi-satellite of co-owned CFAC-TV in Calgary (now CICT-DT)[2] and continued local production with shows such as Time Out, Ski Reports, Our Town, Sunday Hour, Thought for the Day, Focus on University, College Campus and numerous specials.

Local programming continued to play an important role at the station, with successful shows such as Ski West, which was syndicated to CHCH-TV in Hamilton, BCTV in Vancouver and CFCF-TV in Montreal, and was also judged best syndicated show in the country at the time; We Won't Let Him Die, which won the CanPro Founders award in 1983; and Kids Belong Together (1990) and Key to Literacy (1992), both shows won the Canadian Association of Broadcasters Gold Ribbon Award for community involvement.

[5][6] The following translators will continue to offer the analog signal after CISA's main Lethbridge transmitter is converted to digital.