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Open Space and Mountain Parks

Open Space and Mountain Parks

Boulder's Open Space and Mountain Parks (OSMP) are a very special place. The open space lands teem with native plants and wildlife and are home to threatened and endangered species. They serve as a buffer between Boulder and nearby development. They sustain agriculture uses and add untold benefits to the natural environment - clean air, water, and earth.

The lands shape the urban mosaic of the Boulder Valley and provide residents with passive recreation opportunities. Trails are used by walkers, hikers, bicyclists, horseback riders, dog walkers and other passive recreational uses.

OSMP Alerts

Trail/Trailhead Closures

Please see the temporary closures page for more details on the trail closures below. OSMP's interactive trail map also shows these longer-term trail closures and restrictions: 

  • Muddy trail closures: Please check the trail map or temporary closures page for any muddy trail closures.
  • Xcel Energy electric transmission line work: Xcel is working in the NCAR area; please check the temporary closures page for details.
  • IBM Connector Trail closure: The trail will be closed west of 63rd St. beginning 9/11. 
  • 1st/2nd Flatiron Trail closure: The 1st/2nd Flatiron Trail will be closed Mon-Thurs every week into the fall.

Project Updates & Other Alerts

OSMP Master Plan Update: City Council unanimously accepted and adopted the OSMP Master Plan pdf on September 3, 2019. Thanks to everyone who participated in this planning process. With City Council’s final adoption of the Master Plan OSMP will begin implementing the plan through a series of actions tied to the strategies and will begin annually reporting on successes in achieving the vision laid out by the plan. This fall staff also will prepare an illustrative document to bring our shared vision to life.

Help improve our interactive trail map! Open Space and Mountain Parks is interested in learning how we can improve your experience when using our interactive web map. Your input on a quick 5-minute questionnaire will inform our work to help the community better connect with OSMP. View the map and survey.

Algae blooms at lakes and ponds advisory: The City of Boulder reminds residents and open space and parks visitors to exercise caution as sustained high temperatures have increased the risk of potentially harmful algae blooms at city lakes and ponds. In particular, the city advises residents to keep children and pets out of Wonderland Lake in north Boulder, where potentially harmful, blue-green algae blooms have been identified. Whenever community members see algae at area lakes and ponds, they should exercise significant caution to keep their pets out of those areas and avoid contact with water. Learn more about the advisory.

Tall Oatgrass Management Program: Learn about why it's so important to aggressively manage tall oatgrass in Boulder County and what OSMP is doing about it:

Purchase OSMP annual parking permits online: Visitors whose vehicles are registered outside of Boulder County can now purchase OSMP annual parking permits online. Learn more about parking permits

Open Space and Mountain Parks Calendar

Free, public Nature Hikes and Programs can be found at

OSMP Master Plan Process Committee

@ 12 to 1:30 p.m.

The OSMP Master Plan Process Committee aims to engage decision-makers in developing, supporting and ensuring best practices for OSMP's Master Plan.

Open Space Board of Trustees Meeting

@ 6 to 8 p.m.

The OSBT usually meets on the second Wednesday of every month. Please view the agenda for meeting information, including start time and location.

View main city calendar for all upcoming city events, or for more events like this

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Featured Projects & Pages

Prairie Dogs in a field

Prairie Dogs

City plans and policies strive to strike a balance between protecting prairie dog populations and natural communities while maintaining open space land uses.

Dog on a trail wearing Voice and Sight Tag

Voice and Sight Tags

Information on how to register for the Voice and Sight Tag Program or renew your dogs' Voice and Sight Tags.

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Interactive Trail Map