CDOT hits the half-way milestone in building the I-25 Greenland Wildlife Overpass, the world’s largest bridge structure for wildlife

News Release

July 25, 2025 - Denver Metro/Central Colorado - Senator Bennet joined CDOT for a project update

Douglas County - Sen. Michael Bennet today joined Colorado Department of Transportation Executive Director Shoshana Lew and the project team at the construction site of what will be the world’s largest bridge structure over an interstate for wildlife. The I-25 Greenland Wildlife Overpass located between Larkspur and Monument will allow wildlife to safely cross, greatly reducing animal vehicle collisions. In an update on the project’s progress, CDOT said it has reached 50 percent completion.

"Colorado is leading the nation in protecting our treasured wildlife by building the world's largest safe passage for animals like elk and moose,” said Sen. Bennet. “This Bipartisan Infrastructure Law investment will lead to a 90% reduction in wildlife fatalities and make this busy stretch of I-25 safer for drivers and animals alike."

"This overpass is the final link in a system that will make I-25 safer for both drivers and wildlife. By completing the wildlife crossing network from Castle Rock to Monument, we expect to cut vehicle-animal collisions by 90%," said Lew. "This is an achievement for both public safety and conservation, and it is a result of the support from our federal delegation, Douglas County, Colorado Parks and Wildlife, and many other partners."

With the project reaching the halfway point, the structure to support the bridge has gone up. This includes the foundation work of piers and columns and 76 girders (38 over each direction of I-25). The remaining work includes building the bridge superstructure over the girders, pouring the concrete bridge deck and tying into abutments, building walls, grading slopes, preparing the soil and wildlife landscaping, and installing wildlife fencing. The bridge structure is expected to be completed in late 2025 with landscaping and other work to finish in 2026.

The overpass addresses specific needs for elk and pronghorn that move around in the Greenland area depending on the season. Both species prefer to cross open structures that provide clear and open sight lines. This stretch of I-25 between Castle Rock and Monument experienced one wild-life vehicle crash a day in the spring and fall seasons. The overpass in combination with five nearby wildlife underpasses will greatly improve safe passage for Colorado drivers and wildlife. Visit the I-25 Greenland Wildlife Overpass Field Update on flickr for pictures of the construction progress and the field update.

Other Facts

  • The wildlife overpass structure will be the largest in the world at 200 feet wide and 209 feet long covering 41,800 square feet, nearly an acre
  • 76 girders will hold up the bridge deck
  • Wildlife that will use the overpass include big game animals such as moose, bear, mountain lions, elk, mule deer and pronghorn and smaller animals as well
  • More than 100,000 vehicles a day travel this area
Sen. Bennet joins CDOT Executive Director Lew and the project team to mark the half-way point of the I-25 Greenland Wildlife Overpass construction.
Sen. Bennet joins CDOT Executive Director Lew and the project team to mark the half-way point of the I-25 Greenland Wildlife Overpass construction.

The girders that will support the overpass structure.
The girders that will support the overpass structure.

Traffic Impacts

  • Throughout the project - daytime off-peak single climbing lane closures
  • July/August 2025 - Nighttime I-25 lane closures for overhead bridge work (pouring concrete deck)
  • As needed throughout the project - Nighttime I-25 lane closures to realign travel lanes

Project Information

Know Before You Go

Travelers are urged to “know before you go.” Gather information about weather forecasts and anticipated travel impacts and current road conditions prior to hitting the road. CDOT resources include:

Remember: Slow For The Cone Zone

The following tips are to help you stay safe while traveling through maintenance and construction work zones.

  • Do not speed in work zones. Obey the posted speed limits.
  • Stay Alert! Expect the unexpected.
  • Watch for workers. Drive with caution.
  • Don't change lanes unnecessarily.
  • Avoid using mobile devices such as phones while driving in work zones.
  • Turn on headlights so that workers and other drivers can see you.
  • Be especially alert at night while driving in work zones.
  • Expect delays, especially during peak travel times.
  • Allow ample space between you and the car in front of you.
  • Anticipate lane shifts and merge when directed to do so.
  • Be patient!

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