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 27, 2017

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

  • Monday, March 27 - Sunday, April 2
    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.

  • Monday, March 27 - Saturday, April 1
    There will be a flagger-control one-lane closure 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.

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.

Update: CDOT Unveils Plan to Cut Nearly Two Years off Construction

US 34 - Damage

CDOT is looking to cut nearly two years off the expected permanent reconstruction on US 34 in the Big Thompson Canyon and, in the process, have little impact to travelers during the busy summer season. The tradeoff for this time savings is closing the canyon again next October through May—the same timing as the current closure.

"If we continued the way we were planning to do the work, the canyon would have been a mess. You would be seeing 30- to 45-minute delays on 34 for the next two-plus years," said James Usher, CDOT’s US 34 project director. "There had to be a better way."

Under the revised plan, when the canyon opens to regular traffic on May 25, drivers will see mostly clear roads—there may be some very minor delays here or there—through the busy summer and early fall seasons. Come early October, the canyon would again close to through-traffic, like it did last year, with regularly timed access for canyon residents.

"We were able to do a lot of work during this last closure," Usher said. "We realized that if we pushed the bulk of the work into another closure, we could have relatively minor impacts to the summer seasons AND we would be done with the work almost two years earlier than what we originally expected."

The closure area in October 2017 through May 2018 will be significantly longer than the current one, extending from the Narrows past Drake.

This summer, crews will be working on the two bridges inside the area known as the horseshoe curve. The benefit to doing this work over the summer is that it is off the roadway and requires minimal traffic impacts. Crews will also begin river work in the Cedar Cove area. Next fall, roadway realignment and river revetment work will begin.

Below are some graphics and documents to better explain the proposed accelerated plan.

words for graphic.jpg

Open House

Please join CDOT and Kiewit to discuss this information at one of the following open house meetings:

  • 4:30-6:30 p.m.
    Tuesday, April 4
    Big Thompson Association Building (Permit Holders only)
  • 5:30-7:30 p.m.
    Wednesday, April 5
    Big Thompson Elementary School
    7702 US 34, Loveland
  • 5:30-7:30 p.m.
    Thursday, April 6
    Estes Park High School
    1600 Manford Ave., Estes Park

Original Commitment


Access permits will be provided for residents on US 34 between the Dam Store and Mall Road, as well as up County Road 43 to Glen Haven The team distributed over 2,500 permits to residents in this area.
The highway will open to permit holders every day at exactly 6 a.m. and 4 p.m. These openings were never delayed or canceled, and additional open hours were added.
Phase one work completed by Memorial Day The highway will reopen just prior to Memorial Day (May 25, actually).
School bus and emergency responders' access will be maintained. Buses were accommodated during the open hours and emergency responders coordinated well with the contractor, Kiewit, to respond to calls in the canyon.
Service providers will have access to the canyon. Service providers successfully used work orders to access properties in the canyon.
Snow removal will be uninterrupted on US 34 and US 36. Kiewit and CDOT maintenance crews teamed to make sure the road was always maintained during snow events.
Swipe table to see more content
  • The highway was opened to all traffic over Thanksgiving, Christmas and New Year's.
  • Permit holder open hours were extended on the weekends whenever the schedule allowed.
  • Local mailboxes were installed for canyon residents with a Loveland zip code.

Video: About the Revised Canyon Plan

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.

Colorado: The Official State Web Portal