Image credits: Dan Austin/Paha Sapa Grotto

After A Mysterious Sinkhole Opens Up Under A Driveway, Cavers Drop In To Investigate

By: Arthur Gold | Published: Jul 05, 2022

It’s every homeowner’s worst nightmare—you’ve just bought a new house out in the suburbs when a giant sinkhole the size of the Great Pacific garbage patch opens up right underneath it—swallowing your new home whole. What began as the uncovering of a small gap under the road turned into an expedition of epic proportions. 

 

 

The locals weren’t happy about seeing their neighborhood turn into a jumping-off spot for a spelunking site. But after the explorers emerged from the hole, they brought with them quite a surprise. Read on to learn about their fantastic voyage into long-forgotten depths and learn the fascinating tale of the pothole that grew into a monster.

Trouble Underfoot

It’s just an average morning in South Dakota. The sun is shining, the birds are singing, and there’s a hum of excitement in the air as one of the streets is cordoned off with orange traffic cones. But there’s no trace of a crash in sight. Curious, you drive by a little closer. 

 

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Image credits: Dan Austin/Paha Sapa Grotto

A couple of men stand in the yard, pointing at the sidewalk. There’s something wrong with it. As you jump out of your car, you feel as though something isn’t right underfoot—as if the ground had become unsteady or less solid than before you first set off for work. 

That Sinking Feeling

As you approach, the men on the grass caution you to watch your step. Then, as your brain begins to process what you’re looking at, you start understanding their cause for concern. A hole approximately 25 feet by 25 feet gapes before you. It’s no normal sinkhole.

 

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Image credits: Dan Austin/Paha Sapa Grotto

Drive gravel, exposed pipes, and darkness stare back at you. You suddenly feel unsteady, as if the lawn below your feet could shiver and crumble at any second. The men tell you that the authorities are on their way. Unsettled, you head off to work.

Hideaway Holes

While heading out to work, Black Hawk county’s emergency management service vehicles pass you by, heading to investigate the crack in the earth under Hideaway Hills. The name “Hideaway Hills” will later ring in your ears with irony. 

 

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Image credits: Dan Austin/Paha Sapa Grotto

But how did this hole first appear? One of the two men on the yard, Albert Reitz, was mowing the lawn above when the hole ripped open. He described a vacuum of wind pulling him back as the earth opened up behind him.

The Crisis Deepens

If he had been standing a few feet closer, he would have been dropped right in. The Black Hawk resident said that he counted his blessings. But the opening of the hole was just the start of it. Over the course of the day, he watched as his once-pristine home began crumbling from the foundations up. 

 

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Image credits: Dan Austin/Paha Sapa Grotto

This was no mere sinkhole. The hole, which had almost ended Mr. Reitz’s life, had destroyed his property. His neighbors were probably wondering what the hole had in store for them as they watched the authorities close off the roads.

The Explorers Arrive

The monstrous hole kept growing. A little while later, as the authorities were trying to figure out the best course of action, a group of explorers called “Paha Sapa Grotto” showed up. They were determined to get to the bottom of the issue. 

 

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Image credits: Dan Austin/Paha Sapa Grotto

These climbers, affiliates of the National Speleological Society, are at the top of their field in cave exploration, science, and conservation. They knew the local authorities were out of their depth and offered their professional help. What they found nearly blew them away.

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We Need To Go Deeper

Vice-chairman of the group, Adam Weaver, seen here assessing the drop, was the first to go down. He saw an opening 80 feet or so deep. Before he proceeded any further, he had one of the diggers remove the dangling concrete sidewalk overhead. 

 

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Image credits: Dan Austin/Paha Sapa Grotto

He tied his rope to a piece of sturdy picket fence and rappelled down. As he descended, however, he realized he wasn’t dropping into a cave. Having assessed the walls and tell-tale signs using his years of experience and expertise, he realized that he had dropped into an old mine.

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Plowing The Dark

The drill holes and mining debris had given it away. In his estimation, the mine went on for another 500 feet. He made a quick sketch of the underground area and headed back up. It goes without saying that the other Black Hawk residents were horrified at his discovery. 

 

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Image credits: Dan Austin/Paha Sapa Grotto

Adam called in the rest of his people to explore more of the abandoned mine. The next day, two fully geared-up teams descended to map the subterranean maze. They determined that the mines ran beneath at least 12 homes in the neighborhood. Uh-oh…

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The Bottomless Pit

Imagine driving home from work one day and finding out from the authorities at your door that your home was built over an abandoned gypsum mine and that your house was in danger of collapsing. You’d probably get a sinking feeling in your heart, to say the least. 

 

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Image credits: Dan Austin/Paha Sapa Grotto

Try as they might, Paha Sapa Grotto couldn’t map the whole mine out. The network seemed to go on forever. Plus, the further in they went, the riskier their exploration attempts became. Today, the mine’s true length is still unknown. Many of its sections have collapsed or flooded.

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An Large Artifact Uncovered

An underground river and old mining debris wasn’t the most interesting item they found down there. Here’s one of the Paha Sapa Grotto team looking at an old convertible deep below the earth. How it got there is anyone’s guess.

 

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Image credits: Dan Austin/Paha Sapa Grotto

But judging by the car’s age, somebody was probably aware of the mine’s location before construction on the neighborhood began. The residents of Black Hawk are seeking over $75,000,000 in compensation from previous owners, developers, and estate agents associated with their now-ruined properties. 

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Hideaway Holes

Sadly, Mr. Reitz, as well as many other former residents of Black Hawk, have been left in the dust since the incident. Many of them have relocated to new homes—but they are still legally bound to pay off payments on their properties—houses that are slowly being dragged under the earth.

 

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Image credits: Dan Austin/Paha Sapa Grotto

Housing investments have proven to be shaky investments over the last couple of decades, but this really breaks new ground. We hope the residents of Black Hawk are able to land upon some level of stability in the near future. 

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