In June 1978, the first Wet Willy’s Water Slide opened west of St. Charles along Interstate 70, as St. Louis’s first water slide attraction. By December 1978, plans were underway to open a Wet Willy’s on a bluff overlooking the intersection of Interstate 44 and state highway 141 in Peerless Park, Missouri. It was designed by Galen B. Pellham, an architect from Springfield, Missouri. The park was a mainstay of the area from approximately 1979 to about 1999. After closing, the water slide site became popular for graffiti artists and skate boarders who rode the concrete flumes. Eventually the structure was demolished.

Peerless Park was incorporated in 1935, but by the 1980s, the town’s population dwindled to less than 50 residents with businesses comprising the majority of the town. On May 1, 1998, the town was disincorporated at the request of its citizens. The neighboring town of Valley Park, Missouri, annexed Peerless Park in 2009.