On April Fool’s Day this year, the owners of Mountain Creek ski resort and waterpark in New Jersey pulled what seemed like a great prank: They replaced the resort’s sign with one for the old Action Park, the notorious “extreme” amusement park that operated on the site from 1978 to 1996. Six visitors died there, and its seemingly anything-goes approach to summer fun earned it the nicknames “Class Action Park” and “Traction Park.”

“At Action Park, it felt like you were in some crazy guy’s backyard,” says Dave Schlussman, a 30-year-old from Greenpoint, who in elementary school belly-flopped so hard out of a failed backflip off the park’s Tarzan Swing — just a swing over a freezing cold pool — that his eyeballs felt bruised. “The rides defied any kind of procedure.”

The place was as packed with urban legends as it was with lawsuits: Some — snakes in the rapids ride — were most likely fiction; others — tales of the owner bribing employees with cash to test drive some of the rides for safety or starting his own insurance company — were real.

But the sign was no joke: Action Park was actually coming back this summer from the original owners.

What’s now open at the 35-acre site in Vernon, NJ, is an amalgam of the old and the new — gone are the race cars with shoddy brakes and the park’s most infamous attraction, a water slide with a full vertical loop, which was open for just a month before knocking around too many kids and shutting down for good.

Which isn’t to say Action Park is tame now. Far from it.

The original owners, who had sold the park in 1998 — to a group that changed the name to Mountain Creek — bought it back in 2010 and started restoring old rides such as a river rapids, which they say the previous owners had dulled down. They’re adding a new $1 million Zero G water slide, which they say will be the world’s tallest of its kind when it opens later this summer pending inspection. Riders stand in a capsule, where a trapdoor drops them into the 100-foot-tall slide.

But it wasn’t until an online documentary about the old Action Park — titled “The Most Insane Amusement Park Ever” — went viral last year that the owners realized: Not only do people remember the old park, which drew a million visitors annually at its prime; they miss it.

“The overall conclusion that the people who went to Action Park have is that it was a phenomenal place,” says Andy Mulvihill, who now owns the resort and is the son of the park’s founder Gene Mulvihill, who died in 2012. “I don’t get approached by people telling me what a terrible place it was. The strength of that passion far outweighed the negative things.”

“Negative things” is putting it lightly. One report claimed that in 1987, five to 10 people per day were being brought into the emergency room from the park. The New Jersey Herald reported the park actually bought the town of Vernon additional ambulances to keep up with demand.

Deaths were caused by, among other things, electrocution in a kayak ride, drowning in the wave pool and a heart attack in ice-cold water.

The old Alpine Slide seemed to be the biggest culprit for mishaps, frequently shredding skin on its concrete track. People reportedly also hit their heads on the floor of shallow pools, got caught in the terrifying suction of the wave pool and suffered abrasions on their legs after having to crawl out of a water slide tunnel. Broken or fractured bones were common, as were busted teeth.

But nostalgia is a potent drug, and the new Action Park is sticking itself right in the main vein: The name and original retro rainbow-colored signs are back. On Saturday, former employees gathered for a reunion. The gift shop is selling tongue-in-cheek “I Survived Action Park” T-shirts.

It might seem like a risky move in the age of helicopter parents and endless litigation. Or maybe it’s the best rebranding since New Coke went back to Classic.

“It was the time before insurance companies had their hands in everything, before everything is tested and rubber-coated within an inch of its life,” says Seth Porges, 30, who co-produced the documentary and lives in Williamsburg. “You might get hurt, but if you walked away, you have a great story.”

New Jersey Sen. Cory Booker tweeted that he still had scars from the old park, but said: “I so want to go again.”

Can the new Action Park recapture the old magic? A handful of the old attractions never left: The 23-foot cliff jump is still there, as are a few water slides. The Tarzan Swing got a safety upgrade, with pads protecting swingers. Eleonora Walczak of Greenpoint, showing off her leg scars from the old park while climbing out of the Cannonball Falls pool on Tuesday, said she was surprised to see the Colorado River ride now required helmets with facemasks.

“There were some really zany things that went on back then,” park president Bill Benneyan says. “In three decades, the industry is different, the regulations are different, the safety training is different.”

The park’s original owner, Gene Mulvihill, has been described alternately as a folksy industrialist in the vein of John Rockefeller, a mad scientist with an oversize toy set or a canny, sometimes pushy businessman who kept politicians in his pocket. The decision to unveil the name on April Fool’s Day was a nod to his mischievous streak.

Mulvihill’s company, Great American Recreation, owned the Vernon Valley/Great Gorge ski area, and started to add rides in 1978 to expand summer business. The first was the Alpine Slide, which sent people down a concrete track built into a hill in a car controlled only by a hand brake.

Henry Winnik, a 29-year-old filmmaker in Cobble Hill, watched a friend make a hard turn and skid down the concrete. The friction ripped off the skin on his right arm from the elbow to the shoulder: “It was raw,” he recalls.

Another rider died in 1980 after being thrown from the slide and suffering a head injury.

Now, the park calls its Alpine Mountain Coaster a “cousin” of the fatal slide. A car glides down a metal track around twists and turns. You control the speed with a hand brake, and spills are nearly impossible because it’s locked onto the track.

Still, the new version of the park isn’t passive, like competitor Six Flags Great Adventure, where every visitor has basically the same strap-in-and-ride experience. Flop the wrong way off the Cliff Jump, and you could end up with bruises all over your legs. The Colorado River ride tossed our raft so close to the cave walls, we were thankful we were wearing those goofy helmets. Oh, and they serve booze to patrons, which creates its own sense of adventure for older park goers.

“Great Adventure is Bon Jovi, safe and corporate,” Winnik says. “Action Park was the Ramones.”

Gene Mulvihill made money in a series of businesses: real estate, early cellphones, MRI technology and cancer research, his son says, and seemed to have created the park out of sheer force of personality.

“He just didn’t accept that you couldn’t try something or do something,” says Andy Mulvihill, one of Gene’s six kids. “He was not a big believer in government control.”

Gene told the Newark Star-Ledger that Action Park was almost a labor of love: “I never made any money up there,” he told the paper in 1996. “All that place did was cost me money.”

Mulvihill set up an insurance company based in the Cayman Islands to cover the park, a move which caught the attention of state investigators. In 1984, he pleaded guilty to charges for setting up an insurance fraud scheme, and was slapped with tens of thousands of dollars in fines, according to court records.

For a long time, Mulvihill deftly outmaneuvered would-be litigants, Porges says. He refused to settle out of court and used his wealth to exhaust claimants. Action Park was reportedly fined just once for not following procedure.

But by 1996, it was facing mounting lawsuits and declining attendance as bad headlines spread. It filed for bankruptcy, $40 million in debt.

Visitors say they remember the park as a lawless Neverland where staff never yelled at anyone.

“Even as a kid you’re like, ‘They should probably be taking this a little more seriously,’” says Andy Fiori, 35, a stand-up comedian and radio producer in Astoria.

Was anyone actually inebriated during work, as rumors say?

“I think that was mostly confined to after-hours stuff,” says Therese Mahler, 41, of Jersey City, who worked at the park through college.

The site weirdnj.com, a repository of urban legends, reported the park used crash test dummies to test rides. Andy Mulvihill says his dad would have him test the rides decked out in hockey pads.

Mahler says the bosses often asked for staff volunteers to test the rides each day. On the rare occasions no one would volunteer, the boss would offer a cash bribe.

The new park has attentive lifeguards with whistles at the ready, and omnipresent safety signage.

“The world’s changed,” Mulvihill says. “I refuse to be involved in any rides where anybody can get hurt.”

Still, if there’s a chance to push the envelope, Demetri Kringas, 24, of Sleepy Hollow, NY, is seizing it.

“We push the limits on this park every day,” says Kringas, visiting the park with friends on a Tuesday. He’s gone headfirst on almost every slide, which is against the rules. “They’re always yelling at us.”

http://instagram.com/p/ppCSJ4utMU/