CDOT Announces Plans for US 285 Passing Lanes & Wildlife Underpass Project

March 4, 2016 - Southwestern Colorado/CDOT Region 5 - CHAFFEE COUNTY - The Colorado Department of Transportation will advertise a project to contractors in January 2017 (to begin construction spring/summer 2017) that will improve the safety and mobility of US 285 north of Nathrop in Chaffee County (about five miles south of the US 24/285 junction).

The total budget for this project (from design through construction) is $4.5 million.

The US 285 Passing Lane and Wildlife Underpass Project will add north- and southbound passing lanes, using primarily right of way on the west side of the current US 285 alignment. The project limits are from approximately mile point (MP) 143.1, just north of Nathrop to mile point 145. The work will add highway width to provide approximately 1.2 miles of passing opportunity for northbound traffic and approximately 1.7 miles of passing opportunity for southbound traffic. The project will also include the addition of a left-turn lane for southbound US 285 traffic turning onto County Road 301/Fisherman’s Bridge.

In addition to highway widening, the work will improve wildlife crossing opportunities, increasing safety for wildlife and drivers in this area, where as much as 70 percent of all reported crashes over the study period are wildlife-vehicle collisions. The project will construct a wildlife underpass at approximately MP 143.3. The underpass will be approximately 85 feet long, 12 feet tall and 32 feet wide. Deer fence will also be installed, which will help channel the animals into the underpass. The eight-foot-tall fence will stretch approximately one-quarter mile south of the underpass and approximately one mile north of the underpass.

Additional features to reduce wildlife-vehicle collisions include “jump-outs” or wildlife escape ramps, which are one-way earthen ramps animals in the highway right of way can use to get back over the fence to safety. Deer guards (like cattle guards only wider) will be installed at highway accesses and small mammal crossings will be constructed under the highway. The CDOT project team is also seeking additional funding for the installation of deer fencing, deer guards and jump-outs further north, between approximately MP 146.45 and MP 146.95, to guide animals to an existing concrete box culvert located near MP 146.7.

CDOT PROJECT INFORMATION: A project web site will be developed closer to the construction start date; those who would like to receive any further announcements regarding this project, please sign up at Choose the envelope icon at the bottom of the page and follow the instructions to sign up to receive CDOT Alerts for your chosen area. This project will be located under the “PROJECTS” choices as is called “US 285 Nathrop Safety Improvements.” If you have questions or comments on this, please write to us or call us via our “Contact Us” button at the bottom of our web site. Updated information regarding traffic impacts on this or other CDOT projects is available at or by calling 511.