The immense crack, which appears to split a hilltop in half, was discovered by startled back country hunters.
A dramatic crack has suddenly formed in the foothills of Wyoming's Bighorn Mountains that measures an
impressive 750 yards long and 50 yards wide. It was discovered recently by surprised back country hunters
who travel frequently to the area in search of game.
First reported by SNS Outfitter & Guides, a hunting company, on their Facebook page, the mammoth chasm
appeared over the course of just a couple of weeks.
Read more: mnn.com
Just to add this, here's the explanation given in the article:
"Apparently, a wet spring lubricated across a cap rock. Then, a small spring on either side caused the
bottom to slide out. He estimated 15 to 20 million yards of movement."
An unnamed engineer was quoted in the article. Just to throw that out there.