Building More Fun Trails

We dig trails!

Building More Fun Trails


  • Online signup and waiver required. Group size is limited.
  • Social distancing protocols are required. Please bring a face covering in case you need to be closer than 6′ to another person.
  • BMA volunteers must adhere to Boulder County Public Health guidelines at all times.

We build and improve multi-use trails across Boulder County. Our trail building events typically take place on weekday evenings and weekends from April to September of each year.

The City of Boulder, the County of Boulder, and the Forest Service recognize BMA as a committed partner thanks to our trail building expertise and the thousands of volunteer hours we donate.

Check out our full schedule of trailing building events – and sign up to join us!

Upcoming Trail Building

Tue 18


Tuesday, May 18 @ 5:15 pm - 8:00 pm
Thu 20


Thursday, May 20 @ 5:15 pm - 8:15 pm
Jun 10


Thursday, June 10 @ 5:15 pm - 8:15 pm



After years of partnership with the Boulder Ranger District, a $30,000 planning grant, and a ton of hard work, the US Forest Service (USFS) has approved an expansion of trails around the Nederland area that is on scale with Buffalo Creek. We are about 80% finished with Phase 1 (out of 4) of this project. This new system includes:

  • 44+ miles of new trails
  • 20+ miles of reclaimed user-created trails
  • New restrooms and expanded parking
  • Future potential to connect trails to Winter Park
  • Ride from Nederland
  • Improved signage and mapping

Heil Valley Ranch

BMA continues to work with Boulder County Parks and Open Space to build and improve the trails at Heil Valley Ranch. In 2019, BMA will help put the finishing touches on the Schoolhouse Skills Loop, a new trail specifically for beginners to be able to hone the skills needed on the trail with alternate lines and obstacles specific to bikes. BMA will also help maintain and improve other trails at Heil.

Marshall Mesa

BMA is partnering with the City of Boulder Mountain Parks and Open Space to improve the trails at Marshall Mesa. In 2017 and 2018, BMA improved over a mile of High Plains trail by taking it out of a drainage ditch and adding fun berms and bumps. In 2018, BMA also worked on Doudy Draw to eliminate trail braiding and added several A/B alternative rock lines. 2019’s work continued on Doudy Draw and Coal Seam, including adding a cow grate. This year we will reroute a damaged section of Community Ditch.

Maryland Mountain

BMA is teaming up with the Colorado Mountain Bike Association (COMBA) to help the City of Black Hawk develop a new trail system! We are helping build three bike-only, downhill-only trails; a flow trail, one blue-rated and one black!

Tolland Ranch Trail

Boulder County Parks & Open Space began construction on this brand new 6.6 mile trail in 2020, and hopefully you’ll be riding high above Eldora Ski Resort by 2022! The Toll Trail will be an important connection between West Magnolia and Jenny Creek and is one of the last puzzle pieces of the Indian Peaks Traverse, a 66 mile multi-use trail from Boulder to Winter Park.

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