CO 119 Boulder Roadway Improvements

Work this Week
May 20-23

4-Hour Canyon Closure Wednesday & Thursday, Weather Permitting
Tuesday Closure Canceled
  • From 10 a.m. to 2 p.m. Wednesday and Thursday, CO 119 will be closed from mile points (MP) 39 to 40 for rock blasting.
    • Starting at 9:45 a.m., crews will stop motorists entering the canyon from Nederland.

7 a.m. - 5 p.m., Wednesday & Thursday:

  • Single- and full-lane closures, with up to five areas concurrently impacted as crews:
    • remove concrete barrier (MP 32 to 33); install embankment (MP 38 to 39); pave and repair potholes (MP 26 to 34); and install culverts (MP 36 to 37).

Trail & Creek Closures

  • 5 a.m. - 2 p.m.: Boulder Canyon Trail closed at the canyon mouth to the Fourmile Canyon trailhead
  • 10 a.m. - 2 p.m.: Boulder Canyon Creek closed for recreational use from Boulder, at the canyon mouth, to the Fourmile Canyon trailhead


  • 24/7: Single-lane closure near MP 39 with traffic controlled by a timed signal
  • Delays of up to 35 minutes through the canyon
  • Speed limits reduced to 25 mph
  • Alternate route: CO 72 to Lefthand Canyon Drive

Work is weather dependent and subject to change.

Project Facts

  • Cost: $31 Million
  • Contractor: Zak Dirt
  • Timeline: Winter 2019 - Summer 2020
  • Location: CO 119 between Boulder and Nederland
  • Alternate Route During Construction: CO 72 is a recommended detour. Learn more about the CO 72 Coal Creek Canyon project.

Starting in March 2019, crews began making repairs to a 15-mile stretch of Colorado Highway 119, between Boulder and Nederland, which was damaged during flooding in 2013.

Work includes:

  • resurfacing 13 miles of highway, and entirely replacing two miles of highway;
  • building concrete islands to improve the roundabout in Nederland;
  • installing new highway directional and safety signage;
  • replacing multiple pipes conveying stormwater drainage under the highway;
  • scaling rock in selected areas to reduce rockfalls on the highway;
  • repairing soft shoulder areas immediately adjacent the highway;
  • replacing 29,000 linear feet of concrete or metal guardrail;
  • removing and replacing materials placed during emergency repairs;
  • excavating areas where the slope had failed in the storm;
  • redesigning and widening specific sections of the roadway;
  • reconstructing embankments; and
  • re-establishing native grass seed and erosion control to slopes that were disturbed during emergency recovery work.

Boulder County Trail Improvements

The project, in partnership with Boulder County, will extend and reinforce sections of the Boulder Canyon Trail. The 10-foot-wide, multi-use trail will be extended from Four Mile Canyon to Chapman Drive—adding two new bike-friendly tunnels under the highway and approximately 3500 feet of length to the trail.

Project Work Hours:

  • 7 a.m. - 7 p.m., Monday - Friday
  • Rock-blasting work hours: 9-11 a.m. and 1-3 p.m. Monday – Friday (April – August 2019)
  • No night or weekend work is planned. However, some work zones will remain closed to preserve the work area.

Travel Impacts & Delays

Various delays from single lane & full road closures are expected throughout the project.  Motorist are strongly encouraging everyone to plan ahead to give yourselves enough time to reach your destination.

  • Expect full highway closures for rock blasting and excavation, with two-hour complete closures.
  • Expect various long-term single-lane closures managed by temporary traffic signals, and various short-term single-lane closures managed by flagging. These lane closures will add approximately 15 to 30 minutes of travel time between Boulder and Nederland.
  • Speed limits will be reduced to 25 mph at lane closure areas. Expect several stops through the corridor.  
  • A permit-load restriction will be in effect.

Boulder Canyon Trail Impacts

  • April – August 2019
    • Crews will close the trail and parking areas adjacent to the trail (near mile point 40) when rock blasting is needed.
    • The trail could be impacted two to three times a week for one day (24 hours at a time) to allow for safe rock-blasting activities.
    • No weekend or holiday work is planned.
  • August - October 2019
    • The trail will be closed below the Boulder Canyon Trailhead at all times, including weekends and holidays.
    • Crews will place signage along the trail, at the opening of the canyon near Boulder City limits.

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