The station began signed on as KWDC on September 15, 1988. It played Jazz music and was owned by Denton FM Radio, Ltd. Less than a month after the station went on the air, owners Bill Mercer and Fred Graham sold it to Larry Greene, who bought it for $6 million. Greene changed the call sign to KJZY. In 1991, KJZY made an unusual move for a commercial station, developing "Operation Jazzy" to help save the station's unique format by soliciting listener donations. Some $25,000 was raised, which was only a small portion of the needed $150,000. By December, the station went dark and was sold. In December 1992, the station went back on the air as KDZR, playing heavy metal rock from ABC Radio Network's Z Rock satellite feed, which was based in Dallas. It was then purchased by Marcos A. Rodriguez on February 1, 1995. It flipped to KHCK, airing Tejano music. The station was also simulcast on 107.9 MHz. In 2004, the station was then sold to Hispanic Broadcasting. Less than a year later, the station changed names and formats to KFZO as a Cumbia music station. A short time later, Univision switched it to a Reggaeton format, calling the station "La Kalle". On February 19, 2009, the Regional Mexican format known as "La Que Buena" was moved from 107.9 FM to 99.1 and was simulcast on 107.1 FM. The Reggaeton station known as "Radio La Kalle" was then moved to 107.9 FM and retooled its format to Latin Pop where it remained until late 2011. In early 2011, its sister station KDXX broke away from the "La Jefa" simulcast. On June 28, 2012, KFZO changed its format to Spanish Adult Contemporary music, branded as "Máxima 99.1" and switching call letters to KDXX. On July 29, 2013, KDXX started simulcasting on KFZO 107.1. In September 2014, the "Máxima" branding was changed to "Latino Mix 99.1 & 107.1" and retooled to a Latin Pop format. On February 17, 2016, Univision swapped call signs and formats once again on 99.1 and 107.9, marking the return of the KFZO call letters to 99.1 FM. A day later, 99.1 returned to its current Regional Mexican format as "La Jefa." The La Jefe branding only lasted a year before the station switched to "ZonaMX."
Signal
Unlike most of the area's FM stations like sister KLNO, which transmit their signals from Cedar Hill, KFZO transmits its signal from an unincorporated area East-Northeast of Alvord. Therefore, KFZO's signal is much stronger in the Northwestern parts of the Dallas/Fort Worth metroplex as well as the cities of Decatur, Bowie, Gainesville, and Sherman, but is considerably weaker in Dallas and areas Southeast of the city itself.
