COLORADO PARKS & WILDLIFE

Approximately 12 miles south of the Wyoming State line on State Highway 13, CDOT in partnership with CPW, has designed a unique project to aid in reducing wildlife vehicle collisions while maintaining permeability across the highway.

The project will use an 8' high wildlife exclusion fence to direct deer and elk to an arch underpass structure and two at-grade crossings with 4' low-fence segments to allow animals to cross the highway where driver sight distance is more favorable. These low-fence sections create a large animal crosswalk between segments of high-fence. At the northern low-fence segment a radar wildlife detection system will be installed to alert motorists of wildlife approaching or crossing the highway.

Due to land ownership concerns and large migratory elk herds numbering in the thousands, traditional wildlife crossing structures would be cost prohibitive at the necessary scale and frequency. These mitigation components, coupled with the reconstruction and widening efforts are anticipated to reduce wildlife vehicle collisions and provide more reaction time for drivers that encounter wildlife crossing the roadway. The anticipated completion date is late summer 2022.

The I-25 South Gap project was needed to expand the only 2-lane portion of the highway (each direction) between Denver and Colorado Springs to 3-lanes. The project spans 18 miles of I-25 between Castle Rock and Monument and includes four large span bridges that are designed as dedicated wildlife underpases and one multi-use structure under the newly constructed six lane highway.

The structures were completed in fall 2021 and are connected by an 8’ high wildlife exclusion fence.CDOT is designing a wildlife overpass located south of Greenland, however construction funding has not been secured. CDOT and CPW partnered on a research project which started in Fall 2021 and continues at least until Fall 2024.The collaboration between CDOT and CPW was a shining example of how both agencies (with different missions) can work together for a mutually beneficial project. Listen to this podcast to learn more.

The project improvements include an eastbound and westbound auxiliary lane, reconstruction of tight curves, shoulder widening and six wildlife underpasses along with wildlife exclusion fence on I-70 on the west side of Vail Pass in Eagle County.

The wildlife underpasses consist of two large structures to pass large ungulates such as elk and deer, and four smaller structures designed for black bear, mountain lion and lynx. The structures are located in the top five miles of the pass and tie into existing large span bridges lower on I-70. The anticipated completion date for the underpasses and associated wildlife features is 2024.

The main goal of the project was to construct new wildlife mitigation structures along a 2 mile stretch of Highway 160 west of Pagosa Springs to reduce wildlife-vehicle conflicts and maintain habitat connectivity. The project includes two large crossing structures, a wildlife underpass completed in 2021 and a wildlife overpass completed in 2022, as well as associated wildlife fence to guide animals to the crossings and associated escape ramps. Highway 160 bisects important deer and elk migration routes and winter range. Wildlife migrating from the high country each fall have to navigate across the highway to access winter range to the south, and then in the spring the animals make their way back across the highway to head north to higher elevation summer range. Whereas, some deer and elk winter along Highway 160 and make regular movements across the highway during the winter months. Wildlife-vehicle collisions made up more than 60 percent of crashes in the project area prior to the project completion. A multi-year study is planned to monitor the impact of the project on reducing wildlife-vehicle conflicts and maintaining wildlife movement permeability.

In 2016, five wildlife underpasses along with two overpasses were completed along a 10.5 mile stretch of State Highway 9 south of Kremmling. Wildlife exclusion fence spans the project area and guides animals to the crossings. CDOT and CPW co-funded a research project from November 2015 through April 2020, researchers documented over 112,000 mule deer successful crossings at the 7 crossing structures, along with elk, black bear, moose, pronghorn, bobcats and many other wildlife species. In addition, there was a 90% reduction in wildlife vehicle collisions carcasses documented during this timeframe. See how this mitigation project has succeeded in providing safe passages for wildlife while improving motorist safety.