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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.
  • 1st/2nd Flatiron Trail closure: The 1st/2nd Flatiron Trail will be closed Mon-Thurs every week into the fall.
  • Settler's Park Trailhead closure: The trailhead will be closed on Thurs. 8/22 for maintenance work. 

Project Updates & Other Alerts

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.

OSMP Master Plan Update: The Open Space Board of Trustees (OSBT) and Planning Board have recommended that City Council accept the OSMP Master Plan with minor modifications. The Final Plan, including minor modifications from OSBT, will be released August 22 and considered by City Council on September 3, 2019. 

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:

OSMP administrative offices have moved: The offices relocated to 2520 55th St. in Boulder.

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

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.

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.

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

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Featured Projects & Pages

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.

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.

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Interactive Trail Map