The City of Boulder is again considering allowing cyclists to use a route that would connect Shanahan Ridge in South Boulder with the Doudy Draw trailhead near Eldorado Springs, reviving a debate between cyclists and conservationists that has divided residents for years.
The current push grew out of mountain bikers’ requests for a safer bike connection during the city’s multimodal survey in April. The Boulder Mountainbike Alliance, an advocacy group that has successfully pushed to maintain bike access in several cases this year, is also championing the route.
“This is about something simple: safe, connected trail access south of town,” the BMA wrote in an April post asking its followers to take the survey. “Right now, if you want to ride from Boulder to Marshall Mesa or to Doudy Draw, you’re pushed onto Highway 170. For adults, that’s uncomfortable. For kids, it’s often a non-starter. We can do better.”
The BMA’s proposal drew strong opposition from some hikers and environmentalists, most notably PLAN-Boulder County, a group focused primarily on preserving open space. In an Aug. 7 email, PLAN urged followers to oppose the bike connection, saying it would harm the area’s grasslands, disrupt hikers and runners who value pedestrian-only trails, and increase maintenance and enforcement costs for the city.
City staff say nothing has been decided and that they will not make a recommendation until residents weigh in. A questionnaire on this and other proposed transportation changes is open until the end of the month.
The questionnaire asks residents whether they would stop using the city’s southern trails if bikes were allowed and which considerations — including safety, environmental impacts and conflicts among trail users — matter most to them.
City staff say that a bike connection would likely improve safety and equity while encouraging more people to travel without cars. Their evaluation also says it could damage habitat and contribute to the spread of invasive plants.
The proposed route would connect the Shanahan Ridge neighborhood in South Boulder to the Doudy Draw trailhead. It would begin at the Greenbriar Connector, follow Thomas Lane to the South Boulder Creek West Trail and continue south along the Mesa Trail to the South Mesa and Doudy Draw trailheads. These existing trails run through the Colorado Tallgrass Prairie State Natural Area, which is home to rare plant species, ground-nesting birds, rare butterflies and other wildlife.
“Adding bikes will likely increase overall visitation, which may affect wildlife movement, access to water, and use of the area,” the staff evaluation reads.
In a recent open letter to PLAN-Boulder County, the BMA argued that environmental protection and a bike connection are not mutually exclusive and that existing trails could be rerouted away from the most sensitive areas.
City staff are scheduled to provide an update to the Open Space Board of Trustees in October. If the board recommends that the city council consider the issue, a vote is expected in the first quarter of 2027.
Strong feelings on both sides
The possible bike connection has dominated recent Open Space Board of Trustees meetings, with residents on both sides raising concerns about safety and fairness.
Karen Bell, a resident who opposes the bike connection, told board members at an Aug. 12 meeting about an elderly friend with whom she has hiked for nearly 30 years.
“We used to ride bikes together until chemotherapy ruined her sense of balance,” Bell said. She added that they now hike pedestrian-only South Boulder trails because her friend cannot move off the trail quickly for passing bikes. “Adding a few more bikes to the already extensive Boulder bike trail system at the expense of the safety of elderly hikers isn’t an equitable trade,” she said.
At the same meeting, Bev Baker of the Boulder County Audubon Society said cyclists would harm an area that supports “multiple species of rare and declining grassland nesting birds, plants, and pollinators.”
Some opponents argued that cyclists can avoid Highway 170, also known as Eldorado Springs Drive, by taking a slightly longer path via the Community Ditch Trail to the south.
Cyclists who spoke at the meeting said they remain concerned about riding on Marshall Road along that route.
“Both Marshall Road and Eldo Canyon are rat runs for distracted drivers,” said Eleanor Hodby, adding that her daughter had been hit by a driver while riding in a bike lane and wearing a high-visibility vest.
“I am sick and tired of worrying if she will come home safely from a mountain bike ride in the South Boulder area whilst well-established plans for a safe, well-designed off-road bike route to Doudy Draw gets bounced around between endless meetings.”
Several members of Fairview High School’s mountain bike team came to the Aug. 12 board meeting to advocate for the bike connection. Team member Xander Lewis said riders must cross Marshall Road twice to reach the Marshall Mesa and Doudy Draw trail systems.
“Drivers are often coming off the highway, and many are still going 40 or even 50 miles per hour,” he said. “Both BJC [Boulder Junior Cycling] and the Fairview High School teams have had multiple close calls. We’ve had drivers come within inches of our handlebars, yell at us, flip us off, and in some cases, hit us. I’ve already been hit once by a car, and while I got lucky, many haven’t.”
A debate dating to 2011
Opponents of the proposed connection also argue that South Boulder’s bike access was settled through a West Trail Study Area (TSA) planning process in 2011. Whether to allow mountain bikes on some trails was one of the few issues on which the community group leading that process couldn’t agree. The group left the decision to staff and the Open Space Board of Trustees. The board then recommended that the Boulder City Council maintain a mountain bike ban on nearly all city trails. In March 2011, the council voted to maintain the bike ban.
A reroute of the South Boulder Creek West Trail is allowed under guidance in the West Trail Study Area plan, but city staff have said that “adding bikers would be counter to previous plan guidance.”
PLAN-Boulder County argued that “our current West TSA Plan took 2 years and was notable as one of the city’s most in-depth and complete public processes” and “it cannot be easily changed without unraveling the interwoven agreements.”
The Boulder Mountainbike Alliance, which has long chafed at the city’s bike ban, disagreed. In its recent open letter to PLAN, the BMA argued that “considering one specific connection does not mean throwing out the West TSA or reopening every decision made in 2011.”
“Plans for public lands need to be able to respond when conditions, community needs and opportunities change,” the group wrote. “The question before the City today is much narrower: can one safe bike connection be created while protecting the conservation and visitor experience goals of the West TSA?”
