It’s the greatest water park in the world.

A summer afternoon at Johnson’s Shut-Ins will make you forget about manmade water parks. That’s because it pushes humans through some of the most hair-raising chutes a body can stand without drowning. Or so I thought.

The rushing water is entirely natural, no chlorine. And the ride is free.

On a recent visit to this dependable waterworks, I joined family members who turned themselves into torpedoes, sliding through a maze of hydraulics that has yet to meet its manmade match.

The ride never breaks down. Flowing over the oldest exposed rocks in North America, a mountain stream gets forced through a narrow granite canyon strewn with boulders the size of Volkswagens, and the water smashes into this boulder field with the force of your favorite log flume. Visitors come from hundreds of miles away to camp in the campground and spend whole afternoons riding the chutes and spills through this maze, Mother Nature at her playful best.

On a hot summer day, our family participated willingly, alongside a thousand other water worshipers, who were there that day tumbling out of control through fissures that could easily render us dazed or comatose. Surprisingly, all afternoon we didn’t see an injury worse than a sunburn. I’m amazed that in this modern age of limits and lawsuits, caveats and crowd control, such a thrill ride still exists.

But one early morning a few years ago, things went horribly wrong. A tragic event revealed that not everything along this slice of fun is natural.

High atop Proffit Mountain, a manmade reservoir regulates the mountain stream. This mountaintop lake is operated by a large utility company, which pumps water up the mountain to the reservoir at night when electricity is cheap, and releases it through turbine generators during the day when electric demand is high. Proffit Mountain, indeed.

Well, a series of mishaps atop the mountain caused the reservoir to overflow the dam, which broke, sending two billion gallons of water scouring down the mountainside. While the rocks of the shut-ins didn’t budge, the torrent ripped through the state park, sending a wall of water and boulders and trees that pulverized the campgrounds. The force of the water performed a facelift so complete that it shut the park down for several years.

It was a major catastrophe, an event every bit as turbulent as the Johnstown Flood, but because of timing and luck, nobody died. If the flood had happened in the spring or summer or fall, it would have killed hundreds of campers. Instead, it happened on December 16, and the campground in the state park was empty, except for the park superintendent and his family. The flood unhinged the park superintendent’s house, and dashed it against canyon walls downstream.

Searchers found the family the next morning, hugging the tops of two trees that had withstood the raging water. All five family members were plucked to safety. They were suffering from shock and hypothermia, but alive. It’s damn near a miracle that the youngest child, a five-year-old, hung on to a tree limb through the night. That five-year-old was fortunate.

–from Coastal Missouri

(Missouri State Parks photos)