The Fox billed itself as "Mellow Rock." It was an AC format that added some classic rock cuts that fit. It had a very short playlist, playing 20 year old songs at a very high rotation. When The Fox made its debut in 1991, St. Louis was in an already crowded market of classic rock and AC radio.
Barry Baker bought the Chapter 11'ed KSTZ in 1990. Baker entered into a Local Marketing Agreement (LMA) with Sunny 101 (WSNL), and create a simulcast with the two.
The format launched in March 1991, following a long computer countdown from 10 thousand to one.
This format continued until February 1993, when Baker flipped KFXB to KPNT. WFXB continued on, but it underwent a change to AAA in the summer of 1993. After three months as a "Classic Rock That Really Rocks" format in September 1994, they adopted the AAA format as WVRV "The River" at Thanksgiving of that year.