Chapman Drive Trailhead Project

OSMP will need to close a recently constructed underpass that connects the Boulder Canyon Trail to the Chapman Drive Trailhead for approximately three months to install the new bridge, weather permitting. A closure at the Chapman Drive Trailhead to complete trailhead improvements is expected to extend further in the summer. View a map of the closure area below.

The Chapman Drive Trail and the existing vehicle bridge from the highway and Chapman Drive Trail will remain open. Visitors to the area will be able to utilize the existing vehicular bridge to connect to the Chapman Drive Trail during the duration of the project. The Boulder Canyon Trail – except for the underpass near Chapman Drive Trailhead – also will remain open. See map below. Visitors can consider alternate destinations at OSMPTrails.org.

OSMP will work to complete the bridge as quickly as possible to minimize the length of the underpass closure. Work on the bridge is the first phase of Chapman Trailhead improvement work and OSMP plans to complete bridge installation this spring – sometime in May or early June – before the busy bicycling summer season.

Trailhead work and its associated closure are expected to extend into the summer. However, bikers, hikers, and equestrians will still be able to access and travel through Chapman Drive Trail despite the temporary trailhead closure.

OSMP recognizes the unique, connected outdoor experience that Boulder Canyon Trail and minimize disruptions in this important trail corridor as much as possible. Staff will assess whether there are times when the underpass can safely reopen during non-construction periods.

In evaluating detour options for the underpass closure, visitor safety remained the top priority. After reviewing options, OSMP determined that no safe detour exists for crossing Highway 119, making the underpass closure the best way to help protect open space visitors.

Improvements for the Chapman Trailhead were identified in the West Trail Study Area Plan developed in 2011. Since then, a new trail bridge to meet multi-use path standards along Highway 119 in Boulder Canyon has been included in the Chapman Trailhead project to provide a trail experience fully separated from vehicles – not unlike the current multi-use path project along Highway 119 from Boulder to Longmont.

The new bridge to connect Boulder Canyon Trail to the Chapman Drive Trailhead is the final phase of the nearly decade-long transportation and recreational improvement project in Boulder Canyon. Ideas to improve transportation and recreational access came after the 2013 floods and led CDOT, Boulder County and the City of Boulder to collaborate on plans to connect the Boulder County Trail, managed by Boulder County, to the Chapman Drive Trailhead. View the county’s project page, including design plans from 2017.

This current project was jointly funded between the City and Boulder County through an intergovernmental agreement, developed many years ago, to implement the project that was planned and designed with community involvement, led by Boulder County. You can view the County’s webpage including the design plans for the bridge from 2016.

The new bridge is required to support a compliant and separated multiuse path for all users such as equestrians, cyclists, hikers, runners, families with children, seniors, and adaptive cyclists or those needing accommodation due to limited mobility. When the City’s Capital Improvement Program prioritized and funded the construction of the Chapman Trailhead last year, city and county staff coordinated to include the bridge into the trailhead construction project as a cost-effective opportunity and to minimize visitor impacts over a longer time horizon by having only one construction project instead of two separate projects at the site. The trailhead and bridge are jointly funded with Boulder County.