News Archive
ATTENTION: This news article is more than 1 year old and information may be outdated.

October 29, 2018

Media Contact

Andrew Barth, 303-441-1032

Lower Fourmile Canyon Drive flood recovery permanent construction underway

Daytime, weekday, nonresidential cycling restrictions remain effective construction

Boulder County, Colo. - Boulder County Transportation and its contactor, Lawrence Construction, have begun the final flood recovery-related construction project in Fourmile Canyon. The project is anticipated to last until November 2019. The project’s goal is to create a more resilient corridor that will better withstand and safely accommodate future flooding, while retaining the special character of the canyon. The roadway reconstruction will support the watershed restoration projects recently completed by the Boulder County Transportation and the Fourmile Creek Watershed Coalition.

Work involves reconstructing the roadway and drainage systems in two sections of the lower portion of the canyon between CO Hwy 119/Boulder Canyon and Salina Junction. Crews began in the south section, which starts approximately one-mile north of CO Hwy 119 and extends to Poorman Road. Early next year, crews will start working on the north sections of Fourmile Canyon Drive as well, which is located between Logan Mill Road and Salina Junction. After structures (retaining walls and culverts) are complete, the two sections of roadway will be repaved to include an uphill shoulder to improve safety and reduce conflicts between bicyclists and vehicles.

“We have made special efforts to ensure reconstruction of the road will respect the unique nature of this beautiful canyon,” expressed George Gerstle, Boulder County Transportation Department Director. “Based on public input, we have made every effort to minimize impacts to the canyon’s rock walls and to the trees and vegetation along the creek. There will be some trees that must be removed in order to build structures on certain limited sections, but we have worked with adjacent property owners to minimize impacts and preserve those trees that are special to residents, and provide replacement trees where we cannot avoid removing them. We very much appreciate the patience canyon residents have shown us as over the past year, and we will do everything we can to minimize inconveniences as we complete our work.”

Working hours are from 8 a.m. to 4:30 p.m., Monday through Friday. Travelers can expect single-lane closures that will be controlled by either traffic signals or flagging personnel. Wait times will vary, but they are not to exceed a total of 15-minutes for a traveler moving through the entire work zone. There will likely be days when extended delays or even roadway closures are needed, but they will only be allowed when necessary and all other options for keeping people moving safely through the construction zone have been exhausted. Up-to-date travel information will be posted to the project website – You can also register your email with the project information group to receive timely information.

In order to maintain a safe travel-way for residents and construction crews, we will continue to enforce the daytime, weekday non-resident cycling restriction. Non-residents will not be allowed to cycle in the canyon between the hours of 8 a.m. and 4:30 p.m. (working hours), Monday through Friday. The road will also be open to all cyclists on major holidays (Thanksgiving, Christmas, New Years Day, etc.).

Canyon residents who rely on cycling for commuting and errands will be exempted from restrictions. Residents will need to carry photo identification that proves they live in the canyon and obtain a cycling pass by contacting Andrew Barth at or by calling 303-441-1032. The passes are good for individual use and are non-transferrable.

The restriction will be enforced by the Boulder County Sheriff’s Office. Anyone violating the restriction could be subject to citation by law enforcement.

The restriction is being enforced due to safety concerns stemming from the extremely high volume of construction activity taking place in the canyon. There are currently four major flood recovery projects taking place within Fourmile Canyon. Each project requires a heavy volume of large truck traffic that heads up and down the road during working hours. Due to the narrow, curvy nature of the canyon’s roads, it has become increasingly difficult to safely share the road between cars, trucks, and cyclists. Trucks hauling materials take up nearly the entire lane, which leaves little room for cars, let along cars and cyclists.

Boulder County Transportation thanks everyone for abiding by the restrictions. We understand how important and popular Fourmile Canyon is for cycling and we will do our best to reduce or lift the restrictions as soon as possible.

Courtesy is Contagious – Share the Road

Boulder County is asking for patience and understanding while the restriction is in place. Canyon roads under repair will see a heavy volume of large trucks and machinery, which will make travel difficult for all modes. The lengths and widths of the trucks used to haul materials can force them into the opposite lane in areas with tight curves and where the road has been narrowed due to a washed out shoulder. In addition, fully-loaded trucks may not be able to stop quickly to avoid cyclists moving downhill. Boulder County would like to avoid any accident that could cause any bodily injury to cyclists or motorists.

Sunshine, Lefthand, James, and other arterial canyon roads that are open to all modes are likely to see a large increase in cycling activity during the work in other canyons. The county is asking all drivers and cyclists to please be aware of their surroundings and other roadway users at all times, and remember to share the road. Motorists are asked to provide cyclists with three-feet of space, if safely possible, when passing, and cyclists are reminded that they are only permitted to ride two-abreast as long as they are not interfering with motorists. During all flood recovery work, Boulder County is asking that all cyclists ride single-file when using mountain roads west of US 36. Motorists are allowed to cross a double-yellow lane-dividing line when passing cyclists, but please use caution doing so when entering curves as an approaching car may not be seen until the two vehicles are too close to avoid collision.

While Boulder County Transportation strives to complete all projects on-time, work is weather dependent and there may be delays due to rain or other unfavorable working conditions.

For more information on the work, visit the project website or contact Andrew Barth, Transportation Department communications specialist, at or call 303-441-1032.

All current Boulder County Transportation roadway project information, including regular maintenance and flood-recovery activity, can be found at

Destroyed section of road in upper Four Mile during the 2013 Flood

Destroyed section of road in Fourmile Canyon as a result of the 2013 Flood (September 2013)