US 34 Big Thompson Canyon

Travel Impacts

Sept. 17-23

  • US 34 remains open to all traffic between Estes Park and Loveland.
    • Expect approximate 15- to 30-minute delays when traveling the canyon.
  • From 8:30 a.m. - 5 p.m. Monday, Sept. 18 - Friday, Sept 22:
    • Expect a possible 2,000-foot rolling lane closure from mile points (MP) 77 to 80.
    • Traffic will be controlled by flaggers.
    • Expect approximate 20-minute delays.

US 34 Closure Begins Oct. 2
Section Available Only to Emergency Vehicles & Permit Holders

Starting Monday, Oct. 2 and continuing through Memorial Day weekend 2018, crews will close US 34 from mile point (MP) 67 to MP 83. County Road 43 will remain open up to the US 34 intersection.

Canyon residents* who want through access on US 34 from 6-8:30 a.m., and from 4-7 p.m. must obtain a vehicle permit by appointment at the following times, dates and location:




4-7 p.m. Sept. 20 2035 N. County Road 29
Loveland, CO
8 a.m. - noon Sept. 23
4-7 p.m. Sept. 28
Swipe table to see more content

If you are unable to attend any of our office hours, please call 970-667-1005 to schedule an appointment.

Note to Residents:

  • You're allowed one permit per vehicle.
  • Permits provide through access on US 34 from MP 67 to MP 83 from 6-8:30 a.m., and from 4-7 p.m. throughout the closure.
  • Permit holders should plan for delays as pilot cars lead vehicles in both directions through the 13-mile work zone.
  • Crews are scheduled to work seven days a week to meet the aggressive schedule.

*Canyon residents are defined as those living along US 34 between Mall Road and the Dam Store along County Road 43 up to Glen Haven.

Overview of Resiliency Measures Being Made

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.

Read the announcement.

See the accelerated plan.

Attention Cyclists

US 34 is now open for bike travel between Loveland and Estes Park. Please use caution as this is still an active work area and hazards may be present.

Specifically, narrow shoulders, rough asphalt, and flaggers may exist around mile point 78.

Please keep in mind that cyclists must follow the directions of flaggers, just as vehicles would, and that this corridor experiences very high traffic volumes during summer months.

See more bicycling safety resources.

Permits Available by Appointment Only

When the work zone is closed, the only vehicles permitted to travel through it 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.

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
  • Construction Start: 2016

Estimated Budget

  • $280 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
Colorado: The Official State Web Portal