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Environmental Review Toolkit


Exemplary Ecosystem Initiatives — 2010

Wyoming: Nugget Canyon Deer Fence and Underpasses

Deer underpass constructed in 2008

Deer underpass constructed in 2008
Source: WYDOT

In 2008, the Wyoming Department of Transportation (WYDOT) completed construction of a deer fence and wildlife underpass in southwest Wyoming. The new underpass system was necessary in order to reduce the number of animal-vehicle crashes along a 14-mile-long stretch of US 30. Prior to the construction of the deer crossing, an average of 130 deer were killed each year along this part of the highway. Deer crossed this section of US 30 in such large numbers because their bi-annual migration route passes over this stretch of road.

An effort to reduce the number of collisions began in 1986 when Wyoming passed the Nugget Canyon Wildlife Migration Project Act. This Act required that State agencies work together to decrease the number of collisions. In 1989, research began to determine the best method to reduce the number of animal-vehicle collisions. Following initial research, an eight-mile fence with one gap, flashing lights, and overhead lighting was installed. Unfortunately, this technique did not decrease the number of animal-vehicle collisions.

In 2000, a 12-foot by 20-foot culvert was installed at the gap in the fence from the 1989 project. With the culvert in place, deer could choose to use the culvert or go around the fence. With assistance from the Wyoming Cooperative Fish and Wildlife Research Unit at the University of Wyoming, the study team determined that additional structures and deer fencing were still needed.

Mule deer using an underpass

Mule deer using an underpass
Source: WEST, Inc.

Following the installation of the culvert and the deer fencing, 6.3 miles of new deer fencing and 6 new concrete underpass structures were installed in 2008. With the aid of WEST, Inc. of Laramie, Wyoming, a three-year-long study is underway to monitor use of the structures along the 14- mile stretch of highway. The study has observed that 24,000 deer as well as 482 elk used the underpass structures. While WYDOT predicted that deer would be frequent users of the underpass, the Department was surprised to learn that elk also used the underpass.

WYDOT forecasts that there has been a decrease in animal-vehicle collisions this year. Furthermore, WYDOT is fixing a fence attachment detail at the bridges and expects the collision rate to continue to decrease. This underpass and fence system is already an example for other wildlife projects within the State of Wyoming. Improvements to public safety and the State's natural resources were achieved by ongoing research and refinement of the deer underpass. Collaboration by WYDOT, Wyoming Game and Fish, the State Legislature, and the citizens of the State of Wyoming enabled the initiation and continued refinement of this project.

For more information, contact Jennifer Hoffman, P.E., Resident Engineer, WYDOT at