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.
People enjoy open space for physical, emotional and mental health. Remember to always be courteous. Don't forget to:
- Plan visits ahead of time and don’t park illegally at full trailhead areas.
- Remember to “keep the space in open space.” Maintain 6 feet of distance from people not in your household.
- Leave No Trace. Stay on trail and walk through mud. If you step off trail to let others pass, immediately step back on trail.
- Protect first responders. Know your limits and don’t take unnecessary risks.
- Visit OSMPTrails.org to see current trail closures, historical data that shows areas of high and low open space use and trails that are wider than 6 feet. See when trails are busiest through our Visitation Data Explorer .
- Marshall Mesa Trailhead closure: The trailhead will be closed 6 am - 4:30 pm on Wed. June 23.
- 1st/2nd Flatiron Trail closure: The trail will be closed 8am-4:30pm, M-Th, beginning June 7.
- Bear Canyon closure: The trail will be closed 6am-5pm M-F beginning May 24. Please visit OSMPProjects.org for details.
- Royal Arch trail closure: The trail is closed through fall 2021.
- Cottontail Trail closure: Portions of the trail will be temporarily closed starting June 17.
- Boulder Star area closure: The area around the Boulder Star is closed.
- South Boulder Creek access closure between South Boulder and Marshall Roads: Creek access is temporarily closed to help prevent the spread of invasive New Zealand mudsnails (NZMS). Please visit NZMS page for details.
- Anemone Trail intermittent closures: Please visit OSMPProjects.org for project and closure details.
- Muddy trail closures: Please check the trail map or temporary closures page for any muddy trail closures.
Tall Oatgrass Management Program: Grazing and its associated livestock fencing are an important part of a continuing OSMP restoration project to help contain tall oatgrass – a highly invasive, non-native grass – in the area.
Free, public Nature Hikes and Programs can be found at NatureHikes.org.
Featured Projects & Pages
View Boulder's live osprey camera. Get a glimpse into the lives of a pair of osprey nesting. Watch them begin nesting, feeding and raising their young.
Visit OSMP's Virtual Open House to learn about a few highlights from 2020 projects along with what to watch for in 2021.
Learn about the science being conducted by OSMP and independent researchers.
The City of Boulder and 11 other agencies created a mobile trails application that provides access to all trail information in and around Boulder County.
Information on how to register for the Voice and Sight Tag Program or renew your dogs' Voice and Sight Tags.
OSMP's Visitation Data Explorer provides a dynamic interface for exploring current data from our fleet of long-term trail counters.
OSMP is developing Integrated Site Projects (ISPs) for several specific OSMP locations, including the Wonderland Lake area, Gebhard property and Gunbarrel Hill.
Interactive Trail Map