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

Winter conditions

Winter conditions exist across open space!

Trails may be icy & slick.
Wear appropriate gear, such as traction devices for your shoes/boots.
Do not walk on ice-covered lakes and ponds.

COVID-19

People enjoy open space for physical, emotional and mental health. Remember to always be courteous. Don't forget:

Only recreate with household members.
Wear a face covering when passing others.
Stay on trail/walk through mud. Avoid stepping on vegetation.
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.
Protect first responders. Know your limits and don’t take unnecessary risks.

Boulder Star closure

The Boulder Star area on Flagstaff Mountain IS CLOSED to prevent gatherings amid the COVID-19 pandemic and because of ecological and safety concerns in the area. Visitors entering the Boulder Star closure area on Flagstaff Mountain can face up to a $1,000 fine or 90 days in jail.

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:

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.
Gregory Canyon restroom closed: The restroom is temporarily closed because of maintenance issues.
Muddy trail closures: Please check the trail map or temporary closures page for any muddy trail closures.

Project Updates & Other Alerts

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.