The station signed on the air on February 12, 1962. The original call sign was KPIR and it broadcast on 1500 kHz. KPIR was a daytimer station, powered at 10,000 watts using a nondirectional antenna but required to go off the air at night.
The call sign was changed to KPNW on September 25, 1967. Shortly afterward, the station's owner, Emerald Broadcasting Corporation, changed its name to Pacific Northwest Broadcasting Corporation.[3]
For most of the 1960s and 1970s, KPNW had a middle of the road format, with popular adult music, news and sports. It was a network affiliate of ABC Radio. In 1968, it added a sister station, 99.1 KPNW-FM. At first, the two stations mostly simulcast their programming, but KPNW-FM eventually had its own format of beautiful music. Today, it is KODZ.
In May 1969, KPNW moved to the current 1120 kHz frequency. It increased power to 50,000 watts and began using a directional antenna. The directional signal is necessary to avoid causing interference to KMOX in St. Louis, which is the dominant Class A station on the same frequency. At 50,000 watts full-time, KPNW is the most powerful AM station on the West Coast between San Francisco and Portland.