A river ran through it.
That’s how Zach Hillman described flooding at the St. Anthony Sand Dunes last month. The combination of snow runoff and a Thursday rain storm created the waterway through about a mile of the popular recreation spot, he said.
“Somebody said ‘A river went through the dunes.’ We started looking for it and found it,” he said.
Hillman headed to the sand dunes with his camera and drone taking pictures and video of the newly formed sand dunes river. Hillman later placed those images on Facebook and since that time, his video has been viewed 20 thousand times as of Monday.
Hillman said that a combination of more than an inch of rain, frozen ground and snow runoff produced a flood that washed away a portion of the dunes.
“So off the Juniper Mountain — that’s what we call it — it looks like the water pooled up and kind of hit this dam area,” Hillman said. “It just got too full. Once it went over the top of that, it made it quite aways across to a farmers’ field. That was kind of interesting.”
Hillman grew up near the sand dunes and said that he had never seen such flooding happen before.
“What it kind of reminded me of was the Teton Dam Flood. It kind of threw the earth around and made its own path and blew through. Some of the sand dunes it took out were pretty good-sized,” he said. “A few spots are very impressive. It was crazy how big it was and how much it washed away.”
Hillman said his dad told him that once there had been hidden lakes on the dunes.
“He said they would pop up in the spring and come out of nowhere,” Hillman said. I haven’t seen them in my lifetime. Now all the sudden this happened. It’s kind of crazy.”
Hillman said that flood waters eventually formed a temporary lake.
“If we got another rainstorm, I think it would start to flow,” he said. “It just pooled up. The water is still just sitting there. It will probably be out there for awhile. Once those sand dunes dry out, this wind moves the sand very quickly. It will cover everything up.”
Bureau of Land Management official Jason Byrd said that he had seen Hillman’s footage of the flooding.
“It looked like the water scoured the sand down to lava rock and created some pretty deep canyon features,” he said.
Such features inside a sand dune region aren’t normal, Byrd said.
“Sand dunes normally have drop offs and cliffs that shift and change all the time. To have something that dramatic — that’s not normal to have water moving through the dunes,” he said. “It does create an additional hazard that I don’t think people are used to. It’s kind of an abnormal event to have that much material moved that quickly.”
Byrd said that BLM sent two workers to the sand dunes on Monday to inspect the situation, and the organization would know more about the flood later this week.
In the meantime, no one has been injured and no Fremont County roadways have been damaged, said Fremont County Sheriff Len Humphries. He said the sand dunes flood was a first for him.
“I have never seen that amount of runoff at the sand dunes,” he said.
Just like Hillman and Humphries, Fremont County Emergency Management official Keith Richey said he’d never seen flooding at the sand dunes.
“It’s impressive,” Richey said. “You look at that, and there’s a lot of power involved there.”
While it’s powerful, residents needn’t worry that the flooding will stretch down into the valley, Richey said.
“It doesn’t pose any threat to the public,” he said.
Humphries doesn’t expect the flooding to have an impact on the sand dunes during the upcoming summer months.
“I don’t see that this is going to make a big change to the sand hills. Some areas obviously have a wash in them, and the first time we get a windstorm, it will blow in new sand,” he said.
People should always be careful while on the sand dunes, Humphries said.
“People need to be cautious,” he said.
Hillman urged residents to be careful if they decide to visit the sand dunes lake.
“If you’re going to go out there, just be safe and watch out for others. I worry a bunch of inexperienced people will run out and take a look at it. It’s easy to get stuck,” he said.
In the meantime, Hillman says that he and his family enjoy living so close to the sand dunes.
“The sand dunes are in my backyard — it’s a really big back yard, 10,000 acres of sand dunes. We love it out there. It’s a fun place to live,” he said.
For more information on the sand dunes, visit www.blm.gov/visit/st-anthony-sand-dunes.