Boulder Canyon Drive/CO 119 is undergoing construction to repair 2013 flood damage. The improvement project will also resurface and widen the road. As part of this project, the Boulder Canyon Trail will be extended to Chapman Drive with two additional bike underpasses. There will be road delays and closures during construction with one-way traffic stoplights. The project began in March 2019 and is expected to be completed by Spring 2021.
When crews are blasting rock, Boulder Canyon Drive will be closed to all car and bike traffic. The highway is typically closed Monday-Thursday 9:45 a.m. – 2:00 p.m. Because Fourmile Canyon is still closed to recreational bike traffic 8:00-4:30 M-F, both the main Betasso trailhead and the Fourmile trailhead will not be accessible by bike from town.
Update: 9/23/2019 – Boulder Canyon Trail is closed at Mile Marker 40 to Fourmile Canyon Road beginning September 23, 2019 through the end of the year. Boulder Canyon Drive is closed to westbound cyclists from Boulder to Fourmile Canyon Rd. Eastbound cyclists can ride on the highway.
This means that there is no from-town bike access via Boulder Canyon to the following trails:
Other cycling restrictions:
- Between Fourmile Canyon Road and Arapahoe Avenue, there is no westbound cycling and eastbound travel is restricted between the hours of 9:45 a.m. and 2 p.m. Monday through Thursday.
- There are no closures on the Betasso Canyon Link Trail.
- Boulder County is currently making improvements along Fourmile Canyon. At this time, all non-residential cycling is closed through the canyon 8:00-4:30 M-F. Please contact Boulder County for more information.
You can subscribe to text alerts about the canyon closures by texting CO119 to 21000 or learn more information about the project and see this week’s closures.