On October 23, SNS Outfitter & Guides posted a mysterious photo of a massive “gash” in the Earth in Wyoming’s Bighorn Mountains to its Facebook. It didn’t take long before the media picked it up and it went viral.

So what exactly is this gash? It’s a crack that’s about 50 yards wide and 750 yards long, about 40 miles south of Ten Sleep, Wyoming. A couple of SNS guides had seen the crack begin to open a few weeks earlier, but didn’t think much of it. When they came back, though, the gash had grown.

So how did this happen? SNS owner Sy Gilliland isn’t quite sure, telling KUSA: “We don’t really know what caused it, or if it’s done falling.” He continued, “There it was, this huge slide or crack or whatever it is. I don’t really think anyone knows what happened out there, all of a sudden it was just there. I think the reason it’s so fascinating is it’s so big. And it doesn’t make any sense, where it happened it’s just like the ground opened up, and the size of it is just huge.”

Since the gash has earned fame, SNS has gotten some help in learning about its origins. An engineer from Riverton, Wyoming says maybe water did it:

“There was a cap rock being lubricated by a spring. Additionally there was a spring running across east to west, which then caused the entire thing to slide north. The engineer estimated about 15 to 20 million yards of movement. According to the [United States Geological Survey], there has been no seismic activity, so we have no other possible explanations at this time.”

Seth Wittke, Wyoming Geological Survey’s manager of groundwater and geologic hazards and mapping, added, “A number of things trigger them, moisture in the subsurface which causes weakness in soil or geology, and any process that would weaken the bedrock or unstabilize it somehow.”

It’s almost unbelievable that such a massive crevice could just open up, seemingly out of nowhere. SNS has said that it will continue to update as the employees learn more about the gash. Sometimes nature shows us something we hadn’t seen, and we can’t do anything but watch and wonder.