The park was founded as Deer Park in 1956 by L.R. Beardsley, Dr. E.S. Gillam, Hardin Dey and Martin Kasichke. The park originally featured a petting zoo with deer, llamas, monkeys, chickens and ducks, as well as a children's area called Storybook Lane. The first ride was built in 1958, an Alan Herschell 16-gauge train called the Deer Park Special.
In 1968, Roger Jourden purchased the park from then-owner Benny Bensinger for $115,000. After purchasing attractions, the park was eventually renamed Deer Park Funland in 1972. That same year, he added the first three flat rides: Tilt-a-Whirl, Merry-Go-Round and Ferris Wheel. Every few years he would add a few more attractions, with the Scrambler opening in 1975. 1976, the park's 20th anniversary, introduced the Spider, a car ride named Mutley's Putt Putts, and two rides for children.
The park's first roller coaster opened in 1979, a standard model Corkscrew from Arrow Development. The park continued their relationship with Arrow when in 1983 they introduced Logger's Run, an Arrow Hydroflume. The Chance-manufactured Sea Dragon opened in 1987, along with a new C.P. Huntington Train circling the park. 1987 also marked the final year for the Spider, which was sold to Michael Jackson for his Neverland Ranch complex.