US 34 Big Thompson Canyon

US 34 Closed Between Mile Points 77 and 80
Local business throughout the canyon are OPEN during construction.

Traffic Impacts for the Week of March 20, 2017

Please keep in mind that lane closures are weather dependent and subject to change.

  • Monday, March 20 - Sunday, March 26
    US 34 remains closed from mile points 77 - 80 with scheduled residential access. This closure will remain in place until just before Memorial Day 2017.

  • 8:30 a.m. - 4 p.m., Monday, March 20 - Friday, March 24
    There will be daily one-lane closures controlled by flaggers in the narrows from mile points 82-83.

While we know there will be travel impacts in the canyon this summer, we have not yet determined exactly what these impacts will entail. More information on traffic management strategies for this summer and beyond will be made public in March, but delays will occur.

Attention Residents: Permits Available by Appointment Only

The only vehicles permitted to travel through this work zone are emergency service vehicles and, at specific times of the day, people who live in the canyon or are doing business in the canyon.

All other through traffic traveling between Estes Park and Loveland should take the posted detour route. View a map of this detour route.

During snow events, drivers using the US 36 detour route between Lyons and Estes Park must follow any posted traction laws for passenger vehicles or chain laws for commercial vehicles.

US 34 remains open to the east and west of this closure area, so anyone trying to get to a business on the east end of the canyon can still do so from the Loveland side, and anyone trying to get to a business on the west end of the canyon can still do so from the Estes Park side.

This section of US 34 will be closed until late May 2017 so crews can do rock blasting work and haul off materials as part of the permanent repairs being made to the highway following the 2013 flood.

Latest Updates

US 34 - Damage

October 2016 - early June 2017:
Travel on this stretch of highway will be limited to canyon residents, and emergency and essential vehicles and crews perform major rock-blasting and construction work.

This plan balances the comments we heard from canyon residents about needing to commute to work and the concerns of canyon business owners about losing customers with the need to do this high-impact work in the safest, most expedited manner.

While we know there will be travel impacts in the canyon this summer, we have not yet determined exactly what these impacts will entail. More information on traffic management strategies for this summer and beyond will be made public in March.

Flood Impact Analysis

US 34 Big Thompson Canyon was heavily damaged during the 2013 floods, with many homes damaged and over 100 air-lifted evacuations. The canyon and its residents also suffered from flooding in 1976. As a result of these two events, CDOT has been studying the hydraulic flow of the river in the canyon, and its impact on the road and bridges along its path. CDOT also is looking for safety improvements and resiliency solutions to prevent and protect against significant damage from future flood events.

Damage Overview

This section US 34 winds its way through the Big Thompson Canyon, providing major access between Loveland, Lyons, and Estes Park. During the flooding, watershed runoff combined with flows released from Lake Estes Dam and surges from debris dam breaches to produce huge flow surges that exceeded the 500–year flood event.  The canyon section sustained widespread, massive damage.  Major sections of roadway were washed away completely, along with access bridges and retaining walls. In the narrows, much of the roadway and grade were undermined, washing out the pavement from below and exposing the wall support structures.

Emergency (Temporary) Repairs

US 34 - Emergency Repairs
Temporary repairs were completed and the highway was reopened to traffic in both directions on Thursday, Nov. 11, 2013. CDOT and its contractors worked from both the east and west ends of the canyon to assess and repair the damage and restore local access as quickly as possible. Emergency repairs were extensive and included removing debris, re-establishing shoulders and embankments, replacing damaged asphalt, filling washed out sections with concrete fill, repairing local access structures, and repairing damaged drainage structures.

Permanent (Long-Term) Repairs

Permanent repairs will include removing and replacing much of the temporary asphalt, embankment fill, and temporary channel protection; as well as re-vegetating, replacing guardrails, and repairing fencing.  Some of the roadway sections that were not destroyed, but experienced flood water overtopping the roadway, will be analyzed and possibly replaced.

See a brochure that further explains the permanent repair process.

Estimated Timeline

  • Est. Design Start:  Summer 2014
  • Est. Construction Start:  2016

Estimated Budget

  • $50 million


One of the goals in the repair process is to introduce certain betterments (improvements that go beyond bringing the roadway up to standard) to roadway facilities that were damaged and make them more resilient to similar storm events in the future.  Having analyzed the damage caused during the flood event, certain design elements will be incorporated in an effort to prevent or lessen the severe damage that significant flood events can cause. During the permanent repair phase, several alternatives will be developed to ensure that the Big Thompson channel has increased capacity and the roadway has additional high water relief to handle large storm events.

Contact Us
Did you know?

At least eight different entities will be working in the river concurrently with CDOT. Together, we are coordinating with regulatory agencies to ensure water quality is maintained. If you notice water quality issues, please contact the project team: 970-667-1005.

River Work MapClick to enlarge the map of river work.

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