New crevasse forms in Big Horn Mountains

AP News
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Posted: Oct 30, 2015 3:19 PM

CHEYENNE, Wyo. (AP) — A large crevasse that has formed a mini canyon in the Bighorn Mountains of Wyoming is likely a slow-moving landslide, a state geologist said.

The crevasse that developed on a grassy, sloped area at the southern end of the mountain range is about 750 yards long and about 50 yards wide, according to outfitters with SNS Outfitters & Guides who posted a photo of it on their Facebook page.

"It's a pretty good size," Seth Wittke, geologic manager with the Wyoming State Geological Survey, said Friday. "I wouldn't say it's huge. I think there's much bigger ones that we've seen in the state. It's definitely not a small one, I would agree with that."

The owner of SNS was in the backcountry Friday and not immediately available for comment.

Wittke said the landslide could be the result of springs in the area.

"And so what may be happening is that you may have excessive water infiltration into the hill slope that's causing the instability in it," he said.

It's not clear when the landslide started and whether it is still moving, Wittke said, adding his only information about it comes from pictures and anecdotal evidence.

State geologists have not been able to inspect the crevasse yet.

"It's not as big a priority because it's not threatening infrastructure, or population centers or anything like that," Wittke said. "Although we do think it's significant and we want to go look at it. We just have to find the time to get up there."

Wittke said the State Geological Survey has mapped about 40,000 landslides throughout Wyoming.

"They do occur in the state and they occur pretty much everywhere within the state," he said.

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Information from: Powell (Wyo.) Tribune, http://www.powelltribune.com