The station was assigned the call letters KAZT on September 9, 1998, and hit the air at frequency 600 AM. On January 22, 2001, the station changed its call sign to the current KNRO. During much of its life as KNRO the station was primarily a sports format. During that time, the frequency was moved from 600 to 1670 AM. From 2001 to 2010, the station was primarily an ESPN Radio affiliate before changing to Fox Sports Radio.