CO 119 Boulder Roadway Improvements

Expect up to 30-Minute Delays April 15-19

  • Sections of CO 119 Boulder Canyon will be closed, with up to three areas impacted concurrently during working hours.
  • Expect a single-lane closure near mile point 39 at all times to preserve the work zone. Traffic will be managed by a timed traffic signal.
  • Crews will work on drainage culverts between mile points 27 and 33. Locations will change throughout each day, with flaggers guiding travelers around the single-lane closure.
  • From 9 to 11 a.m. and from 1 to 3 p.m. Wednesday through Friday: Crews will close CO 119 from mile points 39 to 41 as they blast rock.
  • From 7 a.m. to 3 p.m. Wednesday through Friday:
    • The Boulder Canyon Trailhead will be closed to the Fourmile Canyon trailhead will be closed.
    • The Boulder Canyon Creek will be closed.

You can subscribe to text alerts about the canyon closures happening the week of April 15 by texting the "canyon" to 313131.

Yes—we will continue to send out emails before all closures. You may email us to request being removed from our list.

No—these alerts will only alert you specifically about the two-hour-long full closures of CO 119.

When you text "canyon" to 313131, you will receive a confirmation text message saying you are signed up. If you don't receive a text within five minutes of subscribing, please resend the message.

Signing up for the service is provided at no additional cost to you. However, depending on your phone carrier and plan, you may incur message and data-rate fees. We will keep texts short to minimize messaging fees.

We plan to send one text per day, on the day before a planned closure. Some texts may be sent on Sundays regarding scheduled rock blasting on Mondays. We also plan to use this service to communicate unplanned emergency closures.

Rock blasting on CO 119 is scheduled from mid-April through August 2019, at which time we will stop texts.

Just send a text that says "STOP canyon" to 313131. You'll receive a one-time opt-out confirmation text.

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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