[5] The transmitter would be located on Mount Hopkins, specifically at a distance from a new astronomical observatory to be built by the Smithsonian Institution, under plans approved by the United States Forest Service.

to serve as its studios and offices; meanwhile, Leo and Lester Ziffren, prominent Los Angeles attorneys, and entertainer Danny Thomas joined as limited partners,[8] as would Monty Hall and Stefan Hatos.

[9] Programming began on February 1, 1967;[10][11] The station aired movies in both English and Spanish, dramas, sitcoms, bull fights, cartoons, and other general entertainment fare.

[19] Meanwhile, the station had found its first true program success: telecasts of Arizona Wildcats men's basketball, which attracted public interest and also raised the profile of the team.

[22] The Adelstein–Berger team also expanded to a second station, owning half of KGSW-TV in Albuquerque, New Mexico, when it launched in 1981; the duo also made an unsuccessful bid for KCPQ in Tacoma, Washington, in 1978.

[28] That September, KZAZ and KGSW-TV in Albuquerque were sold to Mountain States Broadcasting, a joint venture of the Providence Journal Company (ProJo) and Southland Corporation.

[30] Mountain States closed on the purchase in 1985 and set out to change a station that had a "home-cooked" image with Gene Adelstein and his wife Ellen having on-air presences.

[31] An infusion of $250,000 in new equipment and a new Nogales studio plus new syndicated programming purchases were made,[32] and the call sign was changed from KZAZ to KMSB-TV that September to reflect the new ownership.

[36] After the FCC staff dismissed this proposal in 1986, the station solicited congressional support, which prompted the Roman Catholic Diocese of Tucson—builder of competing independent KDTU on channel 18—to allege undue influence because of DeConcini's involvement with the previous ownership.

[38] In September 1991, Mountain States signed a time brokerage agreement with Clear Channel Communications (now iHeartMedia), owner of KTTU-TV (the former KDTU).

After 24 years, KMSB-TV moved into KTTU-TV's studios on 6th Avenue, and Mountain States began programming and selling all advertising time across both stations and providing other services to Clear Channel.

[43] Peter Diaz, the president of media operations at Belo, admitted that when the shooting of Gabrielle Giffords occurred in January 2011, "there was no way we could compete with the resources we had in Tucson".

[43] In November 2011, Belo announced that it would enter into a shared services agreement with Raycom Media beginning in February 2012, citing a lack of advertising revenue and the weakly recovering Arizona economy.

[44][43] This outsourcing arrangement resulted in CBS affiliate KOLD-TV taking over daily operations of KMSB and KTTU and moving their advertising sales department into the KOLD studios (however, they remained employees of Belo).

However, Belo corporate held the project back due to budgetary concerns, and the station continued to air Good Morning Arizona from KTVK.

[65][66] On February 1, 2012, KOLD-TV took over the operations of KMSB—taking over production responsibilities of KMSB's nightly prime time newscast at 9, as well as launching a two-hour weekday morning show (from 7 until 9), Fox 11 Daybreak, on the station.

In addition, KMSB dropped its simulcast of KTVK's Good Morning Arizona, and Fox 11 Sports Force was canceled (with the Sunday 9 p.m. newscast now airing for an hour).

[73] As part of the SAFER Act, KMSB kept its analog signal on the air for two weeks to inform viewers of the digital television transition through a loop of public service announcements from the National Association of Broadcasters.