The park was born in the mid-1970s when Great American Recreation (GAR), new owners of the recently combined Vernon Valley/Great Gorge ski area, wanted to do something with the ski area during the off season. They followed the trend of many other ski areas at the time, and in 1977 began offering an alpine slide down very steep ski trails, then gradually put together Waterworld, one of North America's earliest water parks, at the base of the slopes.
They started out with two speed waterslides in the summer of 1978, and then more waterslides and a small deep-water swimming pool the next year. The early 1980s saw more slides along with a huge wavepool. Finally, Motorworld was carved out of the swampy areas the ski area owned across Route 94. Ultimately, the small park consisting of the Alpine Slide and two speed slides evolved to a major destination with 75 rides (35 motorized self-controlled rides and 40 waterslides).
GAR promoted its new attraction with television commercials in the New York metropolitan area, using the jingle "There's nothing in the world like Action Park!" in several-part harmony (later, "The action never stops ... at Action Park!"). The park soon became a popular summertime weekend destination in and of itself, due to the level of control it offered visitors over their experience compared with most other amusement parks. Some visitors were not even aware that it was part of a ski area.
Action Park's most successful years were the mid-1980s. Most rides were still open, and the park's later reputation for danger had not yet developed. In 1982, the deaths of two visitors within a week of each other and ensuing permanent closure of one ride took place, but that hardly dampened the flow of crowds.
The park's fortunes began to turn with two deaths in summer 1984 and the legal and financial problems that stemmed from the lawsuits. A state investigation of improprieties in the leasing of state land to the resort led to a 110-count grand juryindictment against the nine related companies that ran the resort and their executives for operating an unauthorized insurance company. Many took pretrial intervention to avoid prosecution; head Eugene Mulvihill pled guilty that November to five insurance fraud-related charges. Still, attendance remained high and the park remained profitable at least on paper. The park entertained over a million visitors a year, with as many as 12,000 coming on some of the busiest weekends.
Park officials said this made the injury and death rate statistically insignificant. Nevertheless, the director of the emergency room at a nearby hospital said they treated from five to ten victims of park accidents on some of the busiest days, and the park eventually bought the township of Vernon extra ambulances to keep up with the volume.
A few rides were closed and dismantled due to costly settlements and rising insurance premiums in the 1990s, and at last the park's attendance began to suffer as the recession early in that decade reduced visitation. GAR was finally forced into bankruptcy in 1995, and Action Park operated with no insurance policy for its last several years in operation.
Action Park closed at the end of the season as usual on Labor Day, September 2, 1996. It was assumed that it would reopen on Memorial Day weekend of 1997 as usual. However, the financial state of GAR continued to cast a pall over the operations of both Action Park and the Great Gorge ski resort. Action Park's opening was first pushed back to mid-June 1997, and then 4th of July weekend. These never came to pass, as GAR announced in July that it was shutting down its operations immediately, including Action Park.