Flagstaff Road Reconstruction

New Information:

Flagstaff Road Flood Recovery Reconstruction Complete


During the 2013 flood event, Flagstaff Road was badly damaged. The most extensive damage occurred approximately 1,000 feet up from Gregory Lane, where a major slope failure washed away a 200-foot section of the roadway going up Flagstaff Road.

Flagstaff Road washout area

Temporary measures were put in place following the flood, which provided one-lane, traffic signaled-access to residents and visitors. Permanent repairs are necessary to ensure long-term safety for all users of Flagstaff Road. 


  • A contractor will construct a 200-foot long bridge in the uphill lane that spans the washed out area and more. 
    • The picture to the right is of the drill rig that's currently drilling holes for the caissons that the bridge supports will sit on/in. 
Flagstaff Drill Rig


  • Work began on June 23, 2014 and will be complete on Tuesday, Nov. 25

Traffic Impacts:

  • The full, weekday road closure will end at 3:30 p.m. on Friday, Nov. 21
  • Flaggers will be used to move traffic through the area on Monday and Tuesday, Nov 24 & 25
  • Delays of up to 10-minutes can be expected

Access to Flagstaff Road During Work Hours:

  • Hiking trails on Flagstaff will remain open and accessible during work hours. You must carry your bike down hiking trails - no riding
  • Chapman Drive is open bikers, but you have to take Chapman Drive back down if you want to get back to Boulder prior to 3:30, Monday through Friday. 
  • Gross Dam Road from Coal Creek Canyon Drive/Hwy 72 can be used to access the top of Flagstaff Road

Emergency Services Access:

Flagstaff Road asphalt application October 2014 Arrangements have been made with the Boulder County Sheriff's Office, Rocky Mountain Fire District, and Boulder Police to ensure that emergency responders can respond to any situation both above and below the closure. Emergency crews will be staged above the closure to help shorten response time.

Project Contacts:

Dan DeLange  
Boulder County Transportation

Andrew Barth  (Send Andrew an email if you'd like to join the project email list and receive timely project updates)
Boulder County Transportation - Communications

Contractor = Structures Inc. - 720-244-9150