KWSN (1230 AM "FOX Sports Sioux Falls") is a radio station carrying a sports format with Fox Sports Radio programming. The station serves the Sioux Falls, South Dakota, area. It was acquired by Midwest Communications, Inc. in 2012. This station is also aired on a translator, K251BH, at 98.1 FM.

KDAK, Inc., obtained a construction permit for a new radio station on 1230 kHz in Sioux Falls on November 13, 1947. It could not use the call letters KDAK, as they were assigned to a ship at sea; the new station therefore took the call letters KISD. It had to wait for its dial position to open up: KELO was in the process of moving from 1230 to 1320 kHz as part of a power increase. On May 2, 1948, KELO moved to 1320, and KISD debuted that same moment, using KELO's old tower site and facilities. Together with KIHO (1270 AM), which started on May 28, the two new outlets brought Sioux Falls to a total of four stations.

After filing for increased power in 1959, the FCC granted a daytime power increase to 1,000 watts in October 1961. The boost became effective on March 5, 1962; at the same time, the station picked up the Mutual Broadcasting System, which had lost its affiliate in Sioux Falls the year before as the result of the sale of KIHO to Northwestern College and its transformation into a Christian radio station. It was the first network affiliation for KISD since its 13-month-long hookup with the short-lived Liberty Broadcasting System in the early 1950s.

Verl Thomson, who had founded the station in 1948, sold it in 1966 to a group majority-owned by William F. Buckley, Jr., publisher of the National Review; Buckley and business partner Peter Starr also owned the KOWH stations in Omaha, Nebraska. 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. The station's tower collapsed in 1968 when a boom attached to a sign truck snagged overhead guy wires supporting the mast. The tower, still on Verl Thomson's property, narrowly missed the train motel as it fell.

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. In 1963, under Thomson, KISD lodged a complaint against the Sioux Empire Broadcasting Company, which proposed to build a new station at 1520 kHz; despite a favorable ruling for the proposed station, KISD continued to object. In April 1970, more than eight years after the group had filed, the FCC granted final approval for what would become KCHF.

Starr sold KISD to Stanley Deck, who owned KDIX radio and television in Dickinson, North Dakota, for $700,000 in 1971.

Another North Dakota firm acquired KISD in 1977: Red River Valley Broadcasting, owned by Tom Ingstad, making its first purchase in the state of South Dakota. After the sale closed, the station changed its format to adult contemporary; on May 18, the call letters officially changed to KKRC, the first change in 30 years of broadcasting. The entire air staff was replaced and the station relocated to new studios; on the first day, the newly renamed KKRC partnered with a local gas station to sell gas for 12.3 cents per gallon, reflecting its frequency. The adult contemporary format made KKRC the fourth-rated radio station in Sioux Falls in 1980 and 1981, of a total of nine outlets.

In 1980, Ingstad acquired KLYX-FM 93.5 and relaunched it as adult contemporary station KKRZ. 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. Initially seeking the call letters KXXS, an objection by competitor KXRB forced a change to KYKC (for "kicks").