US 34 Big Thompson Canyon

US 34 Impacts
Week of Sept. 26, 2016

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

  • 6 a.m. - 6 p.m. Monday, Sept. 26: Single lane open on US 34 between mile points 79.5-80; traffic controlled by flaggers
  • 6 a.m. - 6 p.m. Tuesday Sept. 27 - Friday, Sept. 30: Single lane closed, with two lanes open on US 34 between mile points 79.5-80; traffic controlled by flaggers
  • 6 a.m. - 6 p.m. Monday, Sept. 26 through Friday, Sept. 30: Single lane open on US 34 between mile points 78 - 78.5; traffic controlled by flaggers
  • 6 a.m. - 6 p.m. Monday, Sept. 26 through Friday, Sept. 30: Single lane open on US 34 between mile points 77 - 77.5; traffic controlled by flaggers with intermittent 5-minute closures
  • 6 a.m. - 6 p.m. Monday, Sept. 26 through Friday, Sept. 30: Intermittent rolling lane closures on US 28766 between US 36 and CO 66
  • 6 a.m. - 6 p.m. Monday, Sept. 26 through Friday, Sept. 30: Intermittent rolling lane closures on US 36 between Lyons and Estes Park
  • Saturday, Oct. 1 and Sunday, Oct. 2: No Traffic Impacts

Please note that possible 30-minute full closures will be necessary for heavy rock excavation Monday, Sept. 26 - Friday Sept.  30. Notifications will be sent out two days in advance.

US 34 Permanent Repairs:
Residential Permits Available Soon

A full closure of US 34 between mile points 77 and 80 will begin Monday, Oct. 17, and be in place until the start of the 2017 Memorial Day weekend. Until then, this three-mile section of the canyon will be closed to through traffic. US 34 will remain open to drivers east of mile point 80 (near Cedar Cove) and west of mile point 77 (just east of Drake).

The only through access on US 34 from Oct. 17 until next Memorial Day weekend will be for canyon residents through a permit process. Permitted vehicles will be allowed through the canyon from 6 - 8:30 a.m. and 4 - 7 p.m. each day.

See more information about permits.

Latest Updates

US 34 - Damage

US 34 will be open to through traffic in both directions throughout the summer. But when construction work begins in July between mile points 77 and 80 (from just east of Drake to the Cedar Cove area), there will be short-duration lane closures and traffic stops for rock-blasting operations.

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.

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.

Public Open House
  • Thursday, Sept. 29, at 6 - 8 Big Thompson Elementary School (7702 U.S. 34, Loveland, CO 80537)
  • Tuesday, Oct. 4, at 6 - 8 p.m. at Estes Park High School (1600 Manford Ave, Estes Park, CO 80517)

At these open house style meetings, the project team will be available at specific stations to answer a variety of questions and discuss important aspects of the project.

No formal presentation will be given and guests are encouraged to stop by anytime between 6 - 8 p.m. 

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