Colorado Highway 9 wildlife crossings reduce winter collisions
August 3, 2016
winter wildlife collisions
For Highway 9 mile markers 125.9 – 126.9, between the months of November and March
The winding stretch of rural highway between Silverthorne and Kremmling has gained notoriety for wildlife collisions. Over the last 11 years, the 10.6-mile segment of Highway 9 has seen more than 650 vehicle-wildlife crashes, Colorado Parks and Wildlife project consultant Michelle Cowardin said.
Thanks to substantial fundraising by a combination of public and private entities in Grand and Summit counties, the Colorado Department of Transportation (CDOT) selected Highway 9 for its Responsible Acceleration of Maintenance and Partnerships (RAMP) program, starting a $40-million wildlife and safety improvement project in 2015. Improvements include seven wildlife crossings — two overpasses and five underpasses — as well as a wildlife fence, widened shoulder and additional guardrail.
At this point, there is just one remaining underpass to construct. Even better news: the four wildlife crossings that were constructed last summer proved effective the following winter, Cowardin said.
In the northernmost segment of Highway 9, leading up to Kremmling from mile marker 131, Colorado Parks and Wildlife has documented deer, moose, elk, bobcats and even bighorn sheep using the crossings.
"We're very, very, happy with the results so far," Cowardin said.
The numbers also fit the story; in the completed segment of the project, just two animal-vehicle collisions were reported last winter. This is just a fraction of collisions reported in previous winters, ranging from 20 to 50 accidents.
In the "unfinished" segment just north of Green Mountain Reservoir, 37 collisions were reported between November and March.
"We have very few accidents in the summer," Cowardin said. "It's within the mule deer winter range and elk winter range. They come down from the forest to the sagebrush habitat in Grand County in the wintertime."
As herds of ungulates migrate to lower elevations in late October or November, the stretch of highway becomes more prone to collisions. Matters aren't helped by the slick, icy roads that accompany the snow.
Cowardin estimated about 97 percent of collisions involve mule deer. This parallels road kill statistics gathered by CDOT. Last year, in the 10.6-mile stretch of Highway 9, CDOT reported 53 instances of deer road kill, two elk, one fox and four "unknown."
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"A more severe winter will see increased accidents because the deer will be pushed further down," she added. "Animals used to get hit all along the highway before the project began because they would concentrate in the area."
Though CPW does not have the full details on how many animals use the structures, they will continue to monitor the crossings for the next few years. Cowardin observed most animals take to the overpasses first.
"I think here, it's very open habitat," she said. "Some prey species are more hesitant to go through the underpasses initially."
In addition to miles of fence, the project also features more than 60 "wildlife escape ramps." Cowardin described them as six-foot-tall dirt mounds used to help wildlife exit the highway over the fence without being able to enter from the habitat side.
"Right now, we were really happy with the success of the structures and the project as a whole," she said.
Motorists can expect lane closures between Heeney Road and County Road 33, as Kirkland Construction crews construct the southernmost underpass, conduct culvert replacement and earthwork. Upcoming projects include installation of the nearby wildlife fence and continuation of the crossing structures.
South of the project location, Cowardin said CPW will work with CDOT to prevent collisions with moose, which frequent the riparian habitat at the north end of Silverthorne. A video went out in July of a moose in the area that was hit by an SUV; the condition of the moose is unknown, as it wandered off several miles, but five other moose died in collisions this year.
"We are working with CDOT to get some sort of moose crossing sign put up for that stretch of highway," Cowardin said. "We're just going to keep seeing some of these increases in human-wildlife conflicts as the population grows."