The Rise and Fall of Action Park—New Jersey’s Most Dangerous Water Park

Introduction: A Dangerous Playground on Ancient Indigenous Land

Before Vernon, New Jersey, became synonymous with broken bones and the notorious nickname Accident Park, the rolling hills and river valleys of Sussex County were part of the ancestral homeland of the Lenape people, whose Munsee-speaking communities lived, hunted, fished, and stewarded the waterways of northern New Jersey for millennia before European colonization. When Action Park opened its gates in 1978 on the grounds of the former Great Gorge ski resort, it transformed this Indigenous landscape into one of the first modern water parks in the United States—and, arguably, the most dangerous. Founder and CEO Gene Mulvihill built a park where visitors controlled their own rides, a philosophy that produced legendary thrills, ghastly injuries, and a cultural legacy that still fascinates historians of American recreation. To understand how Indigenous land became part of broader Native American cultural geography, we must first look at what stood there long before the waterslides.

The Indigenous Foundations: Lenape Territory and the Wallkill Valley

Vernon Township sits in the Wallkill River valley of northwestern New Jersey, a region long inhabited by the Munsee Lenape, the northern branch of the Lenape (Delaware) people. The Lenape maintained seasonal villages along rivers and streams, practicing sophisticated land management, fishing weirs, and agriculture that shaped the very ecosystems later marketed as recreational wilderness. Water itself held deep cultural and practical significance for Lenape communities—the same element that Action Park would later harness, with catastrophic results, in its wave pools and slides. Water-based travel and recreation have deep Indigenous roots in North America, a heritage explored further in our article on how canoes went from ancient Indigenous exploration to modern recreation.

Genesis of an American Institution: The 1978 Opening

Opened in 1978, Action Park was among the first modern water parks in the United States, arriving during a broader late-twentieth-century boom in outdoor leisure that frequently repurposed Indigenous homelands, waterways, and mountains into commercial recreation destinations. Gene Mulvihill’s founding philosophy was radical: amusement park visitors should be in control of their own experience, deciding how fast and how high they went. At a time when American recreational culture prized individualism, Action Park threw out nearly every convention of ride engineering and rider restraint—and the consequences became infamous.

The Alpine Slide: A Concrete Descent into Chaos

The Alpine Slide exemplified Mulvihill’s hands-off philosophy. Riders took a ski lift to the summit, where photographs of injured children greeted them alongside warnings to keep their arms inside their wheeled devices. One longtime Action Park regular described the ride as essentially a giant track to rip people’s skin off that was disguised as a kid’s ride. In theory, each rider controlled their own speed—but the wheeled sleds were routinely broken. Some had no brakes at all, sending riders careening down the concrete-and-fiberglass track; others had brakes locked on, forcing slow crawls that ended in rear-end collisions from faster riders behind. The park saw its first fatality on the Alpine Slide, when a 19-year-old rode off the track and suffered a fatal head injury. New Jersey’s own records documented at least 26 other serious head injuries and 14 fractures attributed to the ride.

The Tidal Wave Pool: The Grave Pool

One of the first wave pools in the United States, the Tidal Wave Pool quickly earned the grim nickname The Grave Pool. Unlike ocean water, the pool was filled with fresh water, which made patrons less buoyant and left strong swimmers and non-swimmers alike literally in over their heads when waves reached 40 inches at high blast. The 12 lifeguards on duty rescued, on average, 30 people a day on high-traffic weekends. Tragically, the pool was eventually the site of multiple drownings.

The Cannonball Loop: A Vertical Engineering Nightmare

The most infamous attraction was the Cannonball Loop—an enclosed waterslide featuring a complete vertical loop, an engineering concept riders’ bodies were never designed to survive cleanly. According to one enduring urban legend, a test dummy sent down the slide returned with no head. Mulvihill famously offered employees $100 to test new rides, including the Cannonball Loop; despite employees emerging with bloody noses and bruises, he opened it anyway. One account recalls a patron becoming stuck at the top of the loop, after which the park installed a hatch to aid in future rescues. Barely a month after opening—and after countless injuries—the ride was shut down by New Jersey’s Advisory Board on Carnival Amusement Ride Safety. Mulvihill’s son later admitted the family never quite perfected that one, while still expressing admiration for his father’s willingness to hire inventors with untested ideas.

An Anything Goes Culture

It was not only dangerous rides that drew teenagers back summer after summer. Action Park operated on a choose-your-own-adventure mentality with scant adult supervision: former visitors recall underage patrons drinking beer freely and roaming the park unsupervised. Physicians who treated the park’s many injuries noted that most patients were intoxicated, regardless of age. The staff—including Mulvihill’s own five children—were often teenagers themselves, blurring the line between employee and patron.

Closure, Fatalities, and Rebirth as Mountain Creek

Action Park finally closed in 1996. By then, the park was linked to six fatalities, including three drownings in the Tidal Wave Pool and the electrocution death of a 27-year-old man on the Kayak Experience, whose overturned boat brought him into contact with water touched by a loose electrical wire. In 2010, Mulvihill led a committee to buy the property back, and in 2014 the site reopened as Mountain Creek Waterpark, now marketing trained lifeguard staff and stringent, up-to-standard safety features—a striking acknowledgment that the freewheeling model of the past was indefensible.

Historical Context & Key Cultural Takeaways

From a historian’s perspective, Action Park occupies a revealing place in American cultural memory. Its story is inseparable from the land itself: the mountainous terrain of Vernon was Lenape homeland long before ski lifts and waterslides, part of a much older pattern in which landscapes shaped by Indigenous stewardship became sites of commercialized leisure, a dynamic examined further in our piece on Teddy Roosevelt’s conservation legacy and the displacement of Native Americans. Key takeaways include: (1) the park’s 1978 opening made it a pioneer of the American water park industry; (2) Mulvihill’s rider-control ideology, combined with chronically malfunctioning equipment, produced a documented toll of at least one Alpine Slide death, dozens of head injuries, and ultimately six fatalities park-wide; (3) regulatory intervention—most visibly the Advisory Board on Carnival Amusement Ride Safety shutting down the Cannonball Loop—marked a turning point toward modern amusement safety governance; and (4) the 2014 rebirth as Mountain Creek Waterpark reflects how contested land use and public safety eventually converged to reshape the site.

Frequently Asked Questions

Where was Action Park located, and whose ancestral land was it on?

Action Park was located in Vernon, New Jersey, in Sussex County, within the traditional homeland of the Munsee Lenape people of the Wallkill River valley. The Lenape inhabited northern New Jersey’s river valleys for generations before displacement through colonization.

When did Action Park open and close?

The park opened in 1978 as one of the first modern water parks in the United States and closed in 1996. It reopened in 2014 under the name Mountain Creek Waterpark.

How many deaths were connected to Action Park?

Action Park was linked to at least six fatalities during its operation, including three drownings in the Tidal Wave Pool, a fatal head injury on the Alpine Slide, and an electrocution death on the Kayak Experience.

What made the Cannonball Loop so dangerous?

The Cannonball Loop was an enclosed waterslide with a complete vertical loop. Employees who tested it suffered bloody noses and bruises, patrons reportedly became trapped inside the loop, and the ride was closed by safety regulators roughly a month after opening.

Why was the Tidal Wave Pool nicknamed The Grave Pool?

The pool used fresh water rather than buoyant sea water, producing waves up to 40 inches that overwhelmed swimmers and non-swimmers alike. Lifeguards rescued an average of 30 people per day on busy weekends, and the pool was ultimately the site of three drownings.

Concluding Synthesis: Cultural Legacy and Modern Preservation

Action Park endures in American memory as a cautionary tale about deregulated recreation—an era when a generation of Tri-State area youth experienced a summers-long experiment in personal risk on land with a far older human history. Its 2014 successor, Mountain Creek Waterpark, embodies the modern consensus that safety engineering and regulation are non-negotiable. Yet the deeper story remains the land itself: the mountains and waterways of Vernon, New Jersey, carry a Lenape legacy stretching back countless generations, reminding us that even the most infamous chapters of American popular history unfold on Indigenous ground worthy of remembrance and respect. For readers interested in the broader relationship between Native nations and American land use history, Action Park is a small but vivid window into how landscapes pass from Indigenous stewardship to industrial and recreational transformation—and why that layered history deserves to be told in full.