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Dry Piney wildlife crossing complete and will facilitate antelope and mule deer migration through vital area

By
Zak Sonntag with the Casper Star-Tribune, via the Wyoming News Exchange

CASPER — As one of western Wyoming’s primary arteries, U.S. Highway 189 stays busy carrying Jackson-bound tourists, cattle ranchers and oil workers between fields in Sublette and Lincoln counties. 
 
But the road also slices through a vital migration corridor where thousands of pronghorn and mule deer cross biannually. As a result, the stretch of highway connecting the towns of Big Piney and La Barge has one of the highest wildlife-vehicle collision rates in the state. 
 
“In the winter they’re always crossing the road. So when it gets dark and you can’t see the animals it’s just like a slaughter,” said Billy Pape, Superintendent of Roads and Bridges for Sublette County. 
 
The incidents near Big Piney are amongst an annual average of 6,000 vehicle and big game collisions across the state, which result in up to $52 million in combined wildlife and personal injury costs, according to Wyoming Game and Fish. 
 
Pape, who’s driven this stretch of Highway 189 his entire life, says wildlife collisions here have been a decades-long problem. 
 
“On any given day there’d be five, six, seven more carcasses,” he said. 
 
 After years of roadway carnage, help has finally arrived. 
 
The Wyoming Game & Fish Department, along with the Wyoming Department of Transportation, recently completed the Dry Piney wildlife crossing project, an infrastructure project that will facilitate antelope and mule deer migration through an area vital to the Sublette pronghorn herd and iconic Wyoming Range. 
 
The project cost around $22 million and includes nine underpasses along with 17 miles of funnel fencing meant to guide herds to safe crossings. 
 
The crossings come at a critical moment for Wyoming’s pronghorn and mule deer populations, which dipped dramatically over the last year at the hands of a malevolent winter. 
 
Western herds like those wintering near the Big Piney area saw especially high levels of death from starvation and exposure, according to GPS collar data collected by WGF. Wildlife biologists with WGF have not yet completed their official abundance estimate for the state’s mule deer population following last winter’s losses, but figures from their ongoing Focal Herd study offer a dire first read. 
 
Beginning in 2022, researchers place GPS collars on 1,112 individual mule deer from five focal herds around the state — and the numbers for the Wyoming Range wintering near Pinedale look especially bad. 
 
Of the 265 collared animals in the Wyoming Range herd, researchers lost close to 60% of the bucks, over 70% of the collared does, and 100% of collared juveniles. 
 
“Those are really high losses. We haven’t seen that level of mortality in a year to my knowledge anywhere. So very drastic losses,” said Brandon Scurlock, WGF’s Pinedale Wildlife Management Coordinator, who added that these figures do not represent a comprehensive picture of the herd, and that the upcoming abundance estimate is likely to be less dramatic. 
 
“We tried to put these collars out to be representative of the herd, but we know that it’s just one data point. So we won’t know the true extent until we do an excitability estimate in February of this year.” 
 
For one particular complex of the herd — a group totaling between 25% and 30% of estimated 30,000-head Wyoming Range — the Big Piney-La Barge area serves as a migration terminus and winter range, which translates to additionally high levels of hoof traffic throughout the winter months. 
 
“They’re going to use these crossing structures during migration and all winter long because their wintering is on both sides of the highway right there,” Scurlock said. “It’s not uncommon to see several hundred deer directly in the right of way most winters because that’s where they go. So we think this crossing structure should help dramatically reduce wildlife collisions in the stretch.” 
 
For the Sublette pronghorn herd, one of the largest antelope herds in America with a population objective of 48,000, the Big Piney connectivity project plays an especially important role during extreme winters. 
 
Data collected from collared pronghorns show that seasonal losses were higher for animals that wintered closer to Pinedale than for those that made it down to Interstate 80 — underscoring the importance of this particular connectivity project. 
 
“For these pronghorn, if it's a mild to average winter they’ll pretty much stay to the west of the highway. When it gets really bad in those most severe winters, then the animals…bail to [lower precipitation] winter ranges on the other side of the highway,” Scurlock said. 
 

 
The Dry Piney project comes at a moment when Wyoming pronghorns are under pressure on multiple fonts. 
 
In addition to winter-related losses in starvation and exposure, herds have also been under-attack from mycoplasma bovis, a strain of pneumonia native to bovines that began jumping to pronghorn in 2019. 
 
A postseason population estimate from WGF put pronghorn populations at 43,000 in December of 2022; by June, according to a line-transect estimate, the population had dropped to 24,000 — less than half of the target population number sought by wildlife managers in the state. 
 
The losses led wildlife officials to curtail hunting tag quotas, which is one of the reasons hunters as well as other interest groups are increasingly vested in the work of migration corridors. 
 
The Dry Piney connectivity project is a multi-agency effort that drew on the knowledge and resources of 11 separate entities, a point of pride amongst stakeholders who say the effort is a testament to collaborative problem solving. 
 
“To be able to tackle a project of that magnitude, with that kind of cost associated with it? No one entity can bear that burden. If it wasn’t for the partners that were able to come together on this, but also some federal participation and federal dollars, we would still be talking about it,” said Joshua Coursey, a board member of the Muley Fanatics Foundation, a non-profit organization dedicated to wildlife management and the sport of hunting. “I mean, it truly was the epitome of success in the conservation flavor of the day, which is collaboration. Because we had such high mortality last year, it’s going to take a long time to get this [Wyoming Range] herd back to its sustainable level, and a project like this really showcases how important every single deer that we have on the landscape is.” 
 
Collaborators include the following organizations: WYDOT, WFG, Greater Yellowstone Coalition, Muley Fanatics, Volgenau Foundation, Knoblach Family Foundation, Wyldlife Fund, Sublette County, National Fish and Wildlife Foundation, Mule Deer Foundation, Wyoming Wildlife and Natural Resource Trust.
 
As to federal collaboration, the project marks a first — and one of the select few policy areas where Wyoming leaders and Federal agencies are on the same page. 
 
“This was really the first time the Federal Highway Administration awarded what they call a build grant for a wildlife crossing project,” said Angela Bruce, Deputy Director for Wyoming Game and Fish. 
 
Bruce said the award reflects a growing awareness of wildlife issues across the nation. 
 
“The momentum in the nation and the emphasis on wildlife crossings is huge. It has caught the attention of legislators and lay public,” she said. “So there is a huge interest, and you could say maybe pressure, for the federal highways to contribute to the effort.” 
 
Of course, wildlife crossings don’t merely protect ungulates. 
 
Administrators with WDOT emphasize their benefit to motorists, who collectively pay tens of millions every year in Wyoming for costs related to wildlife collisions. 
 
“From the highway safety perspective, not only are you risking injury from hitting an animal, you’re also risking damage to your vehicle. And wildlife collisions cost a lot of money to the driver,” said Stephanie Harsha, Public Relations Specialist for WDOT’s District 3, who continued to emphasize that this is one step in a long and ongoing road. “We want drivers in Wyoming to be safe and we want to protect our wildlife as well. So wildlife collisions are an issue that WDOT looks at constantly.”
 
This story was published on November 2, 2023. 

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