The City of Boulder’s Open Space and Mountain Parks (OSMP) department is gearing up for a major project to improve the North Foothills Trail. This initiative, outlined in the North Trails Study Area (NTSA) Management Plan, aims to enhance the trail’s sustainability, protect ecological resources, and deliver a better experience for mountain bikers, runners, hikers, and equestrians alike.
What’s Changing?
This project will include rerouting approximately 1.3 miles of the trail to address steep grades, erosion, and drainage issues. Improvements will include:
- Enhanced Trail Design: Trail grades will range between 4% and 8%, with gravel surfacing to prevent muddy conditions and ensure durability.
- Mountain Biking Features: Expect enhancements like bermed turns and optional challenge features for riders, while still accommodating all user groups.
- Accessibility: The trail will include features to support adaptive mountain biking, ensuring users with disabilities can enjoy the space.
- Ecological Restoration: Approximately 0.85 miles of old trail segments will be closed and restored with native vegetation to minimize ecological impact.
When Will It Happen?
Construction is set to begin in the summer or fall of 2025 and could wrap up by late 2026. OSMP will provide regular updates as work progresses.
Overview of the planned improvements
1. Highway 36 Underpass: The underpass connecting the Foothills Trailhead to the trails west of Highway 36 will remain unchanged. All planned improvements are focused on the trails west of the highway.
2. Rerouting: This section of Foothills will be routed out of the rocky ravine and moved up on the hillside. This will help with water drainage and erosion issues.
3. North Sky Intersection: The Foothills Trail will be rerouted to meet the North Sky Trail at the same level as the bridge.
4. Underpass: The Foothills Trail will be rerouted to avoid the current path under the bridge and the steep hill leading to the cloverleaf entrance.
5. Trail Realignment: The steep trail sections west of 2nd St will be re-routed to a more sustainable alignment.
Final trail alignments are currently in design – some alterations may be made to meet site conditions and provide for optimal trail experiences.
North Sky Bridge
One question we have heard is, “Why the bridge if the trail won’t be going under it anymore?” We reached out to the City of Boulder and here’s their response.
The North Sky Trail alignment and associated bridge locations were planned and designed throughout the creation of the North Trail Study Area Plan and subsequent integrated site plans. These were multi-year efforts that involved a tremendous amount of public involvement and careful balancing and negotiation of the ecological values of the area with the recreational opportunities. As example, the North Sky Trail itself was a topic of many discussions with the community and decision-makers ranging from not having a trail at all on the west side of US36, to how far up or down it’s located on the hillside and how to protect sensitive habitat. As part of these negotiations and final plan approval, the current alignment of the trail was determined to align along the hillside west of US36 and use as much of the existing railroad grade as possible, which can be viewed as you use the current trail. As such, the railroad grade crosses the drainage area with enough elevation change to warrant a bridge in its current location.
For those who might not have been involved in the NTSA or want to learn more, this webpage https://bouldercolorado.gov/osmp-plans-and-reports provides a copy of the North TSA and is available to view in PDF. Unfortunately, all the trail projects weren’t completed concurrently in the area, and the final aspect of the bridge project includes how the existing Foothills Trail connects in. This project is scheduled this year in 2025 and will allow the visitors and trail users a much more sustainable and pleasing trail experience accessing North Sky Trail and using the new bridge. Some of the more detailed considerations that came into play with the trail alignment and bridge location include:
- Wetlands protection: While the drainage that the bridge spans is often dry (an ephemeral drainage), it is designated as a wetland site, housing numerous species of wetland plants. The opportunity to place the bridge high over the wetland area instead of traversing through it reduces impacts to important wetland habitat.
- Neighborhood access from Dakota Ridge to the southeast is an important part of recreation at this site: Utilizing the bridge location keeps the trail alignment a bit closer to the neighborhood to the east, providing more sustainable and direct trail alignments for the Foothills North Trail project to provide access between the neighborhood and North Sky Trail.
- Enhancing history of the site: The bridge is constructed on the 1880’s railroad grade, and while its design is not entirely accurate to the era, it utilizes a rustic iron aesthetic to pay homage to the history of the site.
- Limiting impacts to the Habitat Conservation Area: The area just west and north of the bridge is designated as a Habitat Conservation Area (HCA). The North Sky and Foothills North Trail projects sought to, where feasible, limit impacts to these areas. The bridge avoids having the trail traverse into the HCA.