[2] In 1990, it became KKSO (in reference to the heritage KSO call sign vacated the prior year).
[4] A construction permit for the expanded band station was assigned the call letters KBGG on November 12, 1997.
[4] It was ultimately decided to transfer full operations to the expanded band station, and on February 2, 2001, the license for KKSO was cancelled.
[6] In July 2024, the FCC granted the KKSO call letters to an Iowa Public Radio outlet in the Des Moines metro on 88.9, effective August 30 of 2024.
This marks a return of the call letters to the Des Moines radio market since they disappeared in the late 1990's.