[10] KISD's studios offices were relocated from a site on the edge of town back to downtown; Thomson remained involved with the station by broadcasting editorials but sold KISD in order to focus on his other businesses, a tourist camp and the Sioux Chief Train Motel comprising retired Pullman sleeping cars.
[11][12] The station's tower collapsed in 1968 when a boom attached to a sign truck snagged overhead guy wires supporting the mast.
[13] While Buckley and Starr changed the music format to contemporary, KISD's opposition to the establishment of new stations in the Sioux Falls area on economic grounds continued from former ownership.
As a result of low ratings, both stations changed formats on January 1, 1982; the FM became Top 40 KKRC-FM, inheriting the former AM sound, while the AM flipped to country.
[21] Initially seeking the call letters KXXS, an objection by competitor KXRB forced a change to KYKC (for "kicks").
[22] Ingstad sold six stations—AM-FM combos in Sioux Falls, Grand Forks, North Dakota, and La Crosse, Wisconsin—to Vaughn's Inc.[23] for $8 million in 1985.
[25] On December 31, 1987, after 18 hours of stunting, KYKC threw out its country format—the records filled two garbage bins—and flipped to oldies as KKFN, "Sioux Falls' Fun Spot", playing much of the same music it would have decades earlier as KISD.
KKRC-FM became classic rock KRRO on a new frequency at higher power; KKFN flipped to talk as KWSN (for "weather, sports and news") and picked up the programs of Larry King and Rush Limbaugh.