Park County officials are still evaluating the damage done by a flash flood that nearly destroyed a bridge on County Road YXD along the South Fork of the Shoshone River southwest of Cody.
The flooding was reported around 2:30 p.m. Wednesday, and Julie Seyfert watched as a torrent of muddy water and debris was sent racing down Boulder Creek.
“We watched a wall of debris build up and surging muddy water begin to overflow the banks,” she said. “Huge logs were floating down the South Fork.”
The Park County Public Works Department announced that the narrow wooden bridge over Boulder Creek on County Road YXD, also known as Hunter Creek Road, is closed until further notice because of the flooding.
Cowboy State Daily confirmed with county officials that the bridge is “structurally compromised” and a temporary bridge was being installed in the vicinity.
Until then, several people living on the opposite side of Boulder Creek are stranded while a temporary bridge is installed.
Hurry Up And Wait
Park County engineer Brian Edwards was watching the flood across County Road YXD for most of Wednesday afternoon and evening.
For most of that time, all he and the heavy machinery from the Park County Public Works Department could do was watch and wait.
The bridge was barely visible under the torrent of muddy water, splintered tree trunks, and massive boulders that had been carried onto the road by the flash flood.
After three hours, Edwards wasn’t even sure if the flood had reached its peak.
“I’m pretty shocked that it’s hanging in there, to be honest with you.” Edwards told Cowboy State Daily at the scene. “It’s an old bridge and was already in pretty bad shape."
Even as Edwards watched, the flow of rushing water was expanding across the road. The roar of the water was punctuated with the loud, hollow thuds of tree trunks smashing into boulders and each other as they rushed down Boulder Creek.
“The guys will probably be here most of the night,” he said. “You don't want to put an operator or piece of equipment in danger trying to get to it, because you can do something that changes the direction of the flow and causes a bigger problem, or get somebody hurt.”
By 6 p.m., the summer sun had broken through the thick clouds over the South Fork. Edwards’s concern was the dark storm clouds over the mountains to the south, which indicated rain was still falling.
“It seems to be coming up even more,” he said. “With the clouds up there, it’s important to know if it’s still raining up high.”
Mudslides, Too
Someone was finally brave enough to drive an excavator into the flood, managing to remove a few boulders and one massive tree, but that was the extent of what could be safely done at the moment.
The road and bridge crews worked until 11:30 p.m. to clear a narrow path through three different mudslides in the area. The slides were more than 100 feet long and, in some places, more than 6 feet deep.
On Thursday, the wooden bridge was “closed until further notice,” Edwards said.
“It’s going to be a little bit before we get something temporary figured out, but it’s important,” he said. “Some landowners up there that have no other way in and out. That’s their only route.”
Park County officials say a Wednesday flash flood nearly destroyed a bridge over the Shoshone River and cut off access for some county residents. “We watched a wall of debris build up and surging muddy water begin to overflow the banks,” said a witness. (Andrew Rossi, Cowboy State Daily) 
Park County officials say a Wednesday flash flood nearly destroyed a bridge over the Shoshone River and cut off access for some county residents. “We watched a wall of debris build up and surging muddy water begin to overflow the banks,” said a witness. (Andrew Rossi, Cowboy State Daily)
More Monsoons
Cowboy State Daily meteorologist Don Day said the flash flood was “classic monsoon” behavior. Several intense thunderstorms were reported in northwest Wyoming on Wednesday.
“I heard from someone in Thermopolis that they got 4.25 inches of precipitation in one hour on Wednesday,” he said. “Thermopolis usually gets around 9 inches of precipitation in the whole year.”
Flash flooding was also reported in Hot Springs County and the North Fork of the Shoshone River during the same period.
Day didn’t have specific statistics for how much precipitation fell on the South Fork on Wednesday, but “several small but intense thunderstorms” moved through the area when the flash flood occurred.
For Day, these should be cautionary tales for Wyomingites.
“There’s a historical precedent for monsoonal rains and flash flooding in late July and August,” he said. “There’s a strong likelihood we’ll see more of these heavy thunderstorms and more flash floods for the next week.”
The Park County Public Works Department hoped to have a temporary bridge installed across Boulder Creek by the end of Thursday.
Edwards said the compromised wooden bridge had already been “high on our priority list for replacement.”
Wednesday’s flash flood made replacing it a top priority.
“We recognize that this is the only way in and out for several people who live on Hunter Creek Road,” Edwards said in a statement. “We will be working with local officials to get the road opened back up as soon as possible.”
Andrew Rossi can be reached at arossi@cowboystatedaily.com.
