KOIN-TV began broadcasting on October 15, 1953, as Portland's first VHF television station. It took on an affiliation with the CBS Television Network, to match the radio station (channel 6 has always been a primary CBS station, and as such, it is the only Portland TV station to never change its primary affiliation). 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. Eventually, Marshall Field sold its stake to Newhouse. Lee Enterprises purchased KOIN-TV in April 1977 from the Mount Hood-Newhouse group. KOIN's first color television broadcast was made on August 14, 1954, only three days after then-NBC-affiliate KPTV (channel 12) had made Portland's first such broadcast.