CO 119 Boulder Canyon Improvements

Boulder Creek Trail Reopens between Boulder and Fourmile Canyon Drive

Big news in Boulder Canyon! It’s time to jump on your bike or go for a mountain stroll because the Boulder Creek Trail reopened between Boulder and Fourmile Canyon Drive on the morning of Saturday, March 6. In this stretch, the trail was removed to install river rehabilitation, roadway protection and improved drainage. The new trail was built in a new alignment to increase safety and accommodate changes to the roadway.

Normal winter trail conditions will exist, so please watch for snow and ice. The portion of the trail west of Fourmile to Chapman Drive will open in later in May.

Sunday, May 10 - Saturday, May 15

  • Tuesday through Friday, crews will be installing a crosswalk near Boulder Falls. Please plan for additional delays in this area. 
  • Crews will also use single lane closures for sign installation between MP 28-40.
  • Flagged single-lane closures will be used between the tunnel (MP 38) and Boulder from 7 a.m. - 7 p.m. Monday through Friday
  • Colorado Highway 119 - Boulder Canyon will have single-lane closures. During working hours, there will be up to three areas impacted concurrently.
  • Up to 40-minute delays are expected through the canyon during work hours. Speed limits are reduced to 25 miles per hour in the construction zones. The work is weather-dependent, and the schedule may change

24/7 Ongoing Impacts

  • Road reconstruction and bridge repair is underway between MP 39 and 40. 
  • Flagged single-lane closures will be used between Nederland and Boulder from 7 a.m. to 7 p.m. Monday through Friday. No temporary traffic signals are currently in use.
  • Motorists will be guided around the single-lane closures with traffic control flaggers.
  • Please continue to plan additional time to travel through the construction zones.

Trail Closures and Cycling Updates

  • The Boulder Creek Trail is CLOSED west of the Four Mile trailhead.
  • Cycling access is now open through the canyon. Cyclists need to follow the last car through single-lane closure areas.
  • The Boulder Falls parking lot (near MP 33) is now open.

Creek Closure

  • The Boulder Canyon Creek will be closed to all uses between Canyon Park Drive (Boulder) and Boulder Falls until further notice.

Project Facts

  • Cost: $31 Million
  • Contractor: Zak Dirt
  • Timeline: Winter 2019 - May 2021
  • 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.

About the Project

In March 2019, crews began repairing 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
  • No night or weekend work is planned. However, some work zones will remain closed to preserve the work area.

Travel Impacts & Delays

Local detours remain available. From Boulder, a northern alternate route can be taken via CO 7, US 36 and CO 72. A southern alternate route is available via CO 93 and CO 72. Please note, motorists taking the southern alternate route should be aware of a current project on CO 72 in Coal Creek Canyon, between Plainview Road (mile point 12.3) and Pinecliffe (MP 24.6). Expect lane shifts and short delays at this work zone. 

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 various long-term single-lane closures managed by temporary traffic signals, and various short-term single-lane closures managed by flagging.
  • Plan for 40-Minute Delays.
  • Speed limits will be reduced to 25 mph in the work zones. Expect several stops through the corridor.  
  • A permit-load restriction will be in effect.

Do Not Drive Distracted

CDOT does not encourage drivers to make calls or use any apps while driving. Distracted driving is the act of driving while engaged in anything—texting, looking after children or pets, talking on the phone or to a passenger, watching videos, eating, or reading—that takes a driver's focus away from the road. Distracted drivers cause an average 43 crashes each day in Colorado. In 2018, there were 15,673 crashes in Colorado that involved a distracted driver.

Finally, CDOT used 100% solar to power the WiFi system. This system will function throughout the night and several days without sun. This wifi will only be available throughout the duration of the project.

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