US 285 Wildlife Underpass in Nathrop

Project Facts

  • Cost: $3.5 million
  • Contractor(s): SEMA Construction
  • Timeline: March 2018 - September 2018
MAP III_US 285 Nathrop Wildlife Underpass_03.05.2018.jpg

From March to September 2018, crews constructed a wildlife underpass near the US Highway 285 and US 24 intersection to Nathrop.


Motorists have killed approximately 70 deer at this location in the last two years and close to 250 in the last decade. In fact, vehicle-wildlife collisions constitute as many as 70 percent of all reported crashes in this area.

Studies have shown that wildlife crossings, coupled with fencing, can reduce collisions by over 75 percent.

The Solution


  • The wildlife underpass is approximately 85 feet long, 12 feet tall and 32 feet wide.

  • Deer fencing was also installed, which will help channel the animals into the underpass. The eight-foot-tall fence stretches approximately one-quarter mile south of the underpass and approximately one mile north of the underpass.

  • Additional features include:
    • "jump-outs," or wildlife escape ramps, which are one-way earthen ramps that animals can use to get back over the fence to safety.
    • deer guards (like cattle guards only wider), which were installed at highway accesses and small mammal crossings under the highway. 
    • widening the highway to accommodate a new left-turn lane for southbound US 285 traffic turning onto County Road 301/Fisherman's Bridge.