KOIN-TV began broadcasting on October 15, 1953, as Portland's first VHF television station and a CBS affiliate on channel 6. At the time, it was jointly owned by Mount Hood Radio and Television Broadcasting Corporation; Newhouse Broadcasting Corporation (now Advance Publications), owner and publisher of The (Portland) Oregonian; local investors and Marshall Field's department stores. The station took its calls from KOIN radio (AM 970 and 101.1 FM), which was a joint venture of Mount Hood Broadcasting and Newhouse.
"We've Got the Touch!" ID (1983–1984)
Lee Enterprises purchased channel 6 in April 1977 from the Mount Hood-Newhouse group.
The "-TV" suffix was dropped on August 31, 1992, fifteen years after KOIN radio was sold off.
"Share the Spirit" ID (1986–1987)
"Get Ready" ID (1989-1990)
"The Look of America is CBS" ID (1991-1992)
"This Is CBS" ID with Translator(1992-1996)
In October 2000, the Lee Enterprises television group, including KOIN was purchased by Indianapolis-based Emmis Communications. On January 27, 2006, Emmis sold KOIN (along with KHON-TV in Honolulu, KSNT in Topeka, Kansas and KSNW in Wichita, Kansas) to the Montecito Broadcast Group for $259 million, only to later announce its sale of all of its stations to New Vision Television on July 24, 2007, which was completed on November 1.
On May 7, 2012, LIN Media announced that it would acquire KOIN and the other New Vision stations for $330.4 million and the assumption of $12 million in debt.
On March 21, 2014, Richmond, Virginia-based Media General announced that it would purchase LIN Media and its stations, including KOIN, in a $1.6 billion merger, which was completed on December 19.
On January 27, 2016, it was announced that the Irving, Texas-based Nexstar Broadcasting Group would buy Media General for $4.6 billion. KOIN became part of "Nexstar Media Group" and is the company's first station in Oregon.
The CBS eye was added for the first time in its logos aside from the slogan now enlargened and set in Montserrat.
1Nexstar operates these stations owned by Mission Broadcasting. 2Nexstar operates this station owned by Cunningham Broadcasting. 3Nexstar operates this station owned by White Knight Broadcasting through an SSA. 4Nexstar operates this station owned by Vaughan Media. 5Predecessor company of LIN Media. 6Currently a repeater for WWLP. 7Joint venture with Warner Bros. Discovery in which Nexstar owns 31% while Warner Bros. Discovery owns the remaining 69%.