Nov 01, 2015 I Paul Seaburn

The Big Horn Mountains are Sliding Down a Mysterious Hole

The Bighorn Mountains stretch 200 miles from northern Wyoming to southern Montana and reach a height of 13,175 feet (4,016 meters) … minus the section that is disappearing down a mysterious crack that suddenly opened at the south end of the range. What caused this hole to open so quickly and deeply? Why are there so many of these cracks and why are they being kept secret?

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In some spots, "The Gash" looks more like a canyon

The massive and mysterious crack – some are calling it “The Gash” – was discovered by Randy Becker of Casper, Wyoming, while hunting on a private ranch 10 miles south of Tensleep, Wyoming. "Massive” means the crack, as of this writing, is 750 yards long by 50 yards wide and estimated to be many stories deep. “Mysterious” means that the crack wasn’t there two weeks ago and there’s disagreement on what caused it and how big it could possibly get.

many cracks

First thoughts on causes for the crack were seismic activity from the Yellowstone supervolcano or fracking. Officials quickly said that no sizable seismic events were recorded in the last few weeks. What else could it be?

One engineer speculated that the crack was caused by a slow-moving landslide. A landslide on the surface? Here’s how that might work. A spring sent water across a hard caprock (like sandstone) that then ran off the edge and eroded the soft rock and soil underneath it, causing the caprock to eventually slide down into collapsing hole, making it bigger and deeper. He estimated that there was 15 to 20 million yards of ground movement. That’s a lot of earth to feel moving under your feet.

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A big piece of the Big Horn Mountains slid down this hole

A geologist pointed out that, while these types of slow-moving landslides are common in the spring and summer, they’re rare in the fall. How common are they? Wyoming Geological Survey Manager of Groundwater and Geologic Hazards and Mapping Seth Wittke says the department has mapped over 40,000 just in Wyoming alone.

Forty-thousand cracks opening in Wyoming? Why don’t we know more about this? A big one opens virtually overnight in Tensleep, which is only 150 miles from the Yellowstone supervolcano. Experts quickly deny any connection. Wyoming is a hotbed for fracking. There’s no cover-ups or secrets in that business, right?

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While the experts argue over whether these ,ysterios cracks are common or unusual, this one keeps getting bigger

One big hole opening overnight is a mystery. Forty-thousand in one state is a trend and a possible cause for alarm.

What do you think?

Paul Seaburn

Paul Seaburn is the editor at Mysterious Universe and its most prolific writer. He’s written for TV shows such as "The Tonight Show", "Politically Incorrect" and an award-winning children’s program. He's been published in “The New York Times" and "Huffington Post” and has co-authored numerous collections of trivia, puzzles and humor. His “What in the World!” podcast is a fun look at the latest weird and paranormal news, strange sports stories and odd trivia. Paul likes to add a bit of humor to each MU post he crafts. After all, the mysterious doesn't always have to be serious.

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