The Greenbriar Connector Trail in South Boulder is closed to bikes
For decades, mountain bikers in Boulder have shared one simple request. We would like a safe, natural surface trail to reach the southern trails at Marshall Mesa and Doudy Draw without riding on roads open to cars. The good news is that the City of Boulder Open Space & Mountain Parks (OSMP) already owns the land where a connection could make sense. The hard part is getting it opened to people riding bikes.
Here’s how the story has unfolded.
2011: The first attempt
After bikes were banned from OSMP trails west of the city from Eldorado Springs to Sanitas in 1987, the next opportunity to regain access was in 2011. During the West Trail Study Area (TSA) process, BMA worked with OSMP and the community to explore bike access west of Boulder. That effort ran into headwinds and ultimately stalled, but it set the groundwork for the idea that this connection matters. We’ve documented this history on our Bike Ban page.
2023–2024: The Marshall Mesa trailhead project brings the issue back
When the Marshall Mesa trailhead was slated for closure during reconstruction in the summer of 2024 and OSMP did not have a detour planned, this gap came roaring back into focus. BMA raised the alarm and presented Shanahan Ridge to Doudy Draw to OSMP staff as one viable solution.
To their credit, OSMP worked with us to build a temporary trail from the RTD parking lot along Highway 93 so people could still ride from town without having to ride more on Highway 170. That detour did the job, and the Shanahan Ridge to Doudy Draw connection idea got shelved again.
7c enters the picture
City staff told us that instead of pushing for an emergency change to gain trail access, the Citywide Strategic Plan 2024 – 2026 Priority Action 7c would be the appropriate process to evaluate multimodal connections like this. That was encouraging. The February 2025 update on 7c kicked off what we hoped would be a productive year of looking at bike and walking access across the OSMP system.
We attended the first 7c presentation in February at the monthly Open Space Board of Trustees (OSBT) meeting. OSMP presented a timeline that included reviewing data, developing solutions, and identifying specific trail and access improvements by the end of 2025. That gave us hope that this connection would finally get its fair evaluation.
September 2025: 7c update
OSMP staff presented an update at the September OSBT meeting of the data collection that had happened so far. Multiple community members spoke in support and OSBT board members urged staff to make evaluating the Shanahan Ridge to Doudy Draw connection a priority.
December 2025: The next 7c update
The next update is coming to the OSBT on Wednesday, December 10, 2025. Staff will share a more detailed project roadmap and talk about the upcoming community engagement process. This is where we believe the Shanahan Ridge to Doudy Draw connection needs to be clearly named, prioritized and evaluated within the workplan.
2026: A new opportunity on the horizon
OSMP already plans to begin designing a Lower Big Bluestem reroute in 2026, as planned in the West TSA document. This project could create the most logical, expedient and cost-effective way to build a safe, off-road connection open to bikes between Shanahan Ridge and Doudy Draw.
Much Success with North Sky, so Let’s Make South Sky Reality
The North Sky trail has been an amazing addition to the Boulder trail network for the entire community, but particularly mountain bikers. Folks can ride from the north side of town on a car-free route on a beautiful, well-designed trail. Now imagine that same opportunity at the south end of town.
This is the moment to look at the big picture. We have a major trail reroute planned. We have a citywide initiative focused on multimodal access. We have support from OSBT. We have staff attention. And we have a real community need for a safer bike route.
BMA is advocating for OSMP to fully evaluate a safe, off-road connection from Shanahan Ridge to Doudy Draw in the early stages of the 7c process. We believe the 2026 Lower Big Bluestem reroute creates a perfect opportunity to do this work in a thoughtful and cost-effective way.
We want riders to have a safer choice. We want fewer cars at Doudy Draw. We want real multimodal access from South Boulder. And we want OSMP to use the tools it already has to explore this connection with the community.
This conversation has been a long time coming. We are excited to see where it goes next.
BMA hopes a new “South Sky” trail can be planned, constructed, and open soon to provide a safe, car-free connection between South Boulder and Doudy Draw trailhead.