Cottonwood Trail Closure
The Cottonwood Trail north of Independence Road and south of Jay Road will be closed from Monday, Aug. 8, through Thursday, Aug. 11, while OSMP conducts maintenance work on a bridge along the trail.
Open Space and Mountain Parks (OSMP) makes every attempt to keep this page as up to date as possible. However, some closures and trail advisories are made on an emergency basis for the safety and well-being of our visitors, wildlife and natural resources. Please watch for these signs during your visit. Accessing closed areas can result in a summons with penalties up to 90 days in jail and/or a $1,000 fine.
Text “OSMP” to 888-777 to sign up for text updates about muddy trail closures.
Cottonwood Trail Closure
The Cottonwood Trail north of Independence Road and south of Jay Road will be closed from Monday, Aug. 8, through Thursday, Aug. 11, while OSMP conducts maintenance work on a bridge along the trail. View alternate trail routes by visiting OSMPTrails.org or downloading Boulder Area Trails App. Equestrian traffic can resume after Tuesday, Aug. 30.
Coal Seam and Community Ditch (east of Highway 93) leash required effective June 6, 2022
OSMP has instituted dog-leash restrictions on the Community Ditch East and Coal Seam Trails because of a coyote den in the area. Multiple reports of a coyote acting aggressively toward dogs, including two known attacks have been received.
2022 Trail Projects and Closures
The following trail projects will lead to closures:
Boulder Star Area Closure
The City of Boulder reminds everyone to view the Boulder Star from afar as it remains closed. No designated trail currently leads to the Boulder Star. Learn more about viewing the Boulder Star from afar.
Creek Closures to Limit Spread of Invasive Mudsnails Instituted
The City of Boulder has closed access to South Boulder Creek at the South Mesa Trailhead to prevent the spread of a highly invasive aquatic species, New Zealand Mudsnails (NZMS). The South Mesa Trailhead and the Mesa Trail will remain open. While the city implemented limited South Boulder Creek closures to help stem the human-caused spread of mudsnails in October, it is taking additional steps to prevent their spread into uninfested stretches of the stream by closing creek access at the South Mesa Trailhead and areas to the west. Learn more about the NZMS closures.
Rock Island 1 in Boulder Canyon closed
Rock Island 1 is closed. The rock fractured and part fell onto the Boulder Canyon Creek path. Sections of the remaining rock have been evaluated as unstable so it is closed until recommended bolting can be completed.
The area closures below do not close any designated hiking trails (climbing access trails may be affected). Please be sure to check for any leash restrictions if you are bringing a dog. Current area closures can be seen on the Wildlife Closures map.
Female bats locate roosting sites in caves and rock crevices along the foothills, where the pups are raised in maternity colonies. The pups suffer high mortality rates even under normal conditions, so these closures help ensure they will remain undisturbed by humans during roosting season. Thank you for your cooperation!
The following areas are closed permanently to human use to reduce the chance of people introducing White-Nose Syndrome.
Learn more about New Zealand Mudsnails and how you can help stop the spread.
Thank you for your cooperation in respecting the closures and providing the owls a quiet place to nest!
These areas are closed to protect nesting burrowing owls every year from March 15-Oct. 31:
This Parks and Recreation property will be closed through Oct. 31 if burrowing owls nest in the area:
All designated trails near these areas remain open to help visitors view wildlife species as they thrive in their native habitats.
The following closure was lifted early on 8/8/22:
The following area on OSMP is closed every year from March 15 to Sept. 10 to protect nesting osprey and Northern Harrier:
The following areas on Parks & Recreation land are closed every year from March 15 to Sept. 10 to protect nesting osprey, northern harrier and American bittern:
All designated trails near these areas remain open to help visitors view wildlife species as they thrive in their native habitats.
The closures listed below are not currently in place. You may review the maps for reference, but these areas are not currently closed.
Thanks to OSMP visitors and volunteers for supporting these closures and the cliff-nesting raptor program! The following areas (listed north to south) are closed from Feb. 1 - July 31 to protect cliff nesting raptors:
The areas below are closed from Nov. 1 to July 31 for the protection of nesting and roosting bald eagles:
Grassland breeding birds have seen widespread and precipitous declines at a continental scale due to a variety of impacts. OSMP provides habitat for several species of grassland nesting birds including Grasshopper Sparrow, Western Meadowlark, Vesper Sparrow, Horned Lark, Lark Sparrow, and Savannah Sparrow. OSMP closes certain areas to help reduce human impacts that could disturb nesting birds.
These closures do not affect designated trails in the area which remain open throughout the closure period.
The following areas are closed May 1 - July 31 every year:
Note: Dogs must be on-leash on Lower Big Bluestem year round due to West Trail Study Area Implementation.
These areas are frequent foraging locations for bears. Leash restrictions protect dogs and their guardians when there is a high probability of encountering bears, and help avoid disturbing bears while they feed during the critical pre-hibernation period.
Seasonal Leash Restrictions are in place Aug. 15 to Nov. 1.
Due to bear activity dogs must be leashed from 8-15 to 11-1 on the following trails:
Grassland Ground Nesting Bird restriction in place May 1 to July 31
The Greenbelt Plateau area is also affected by a seasonal leash restriction for grassland ground nesting birds from May 1 to July 31 every year: Both sides of the Greenbelt Plateau trail from the Community Ditch trail to the Greenbelt Plateau trailhead on Highway 128. Dogs must be on-leash on the Greenbelt Plateau trail, view map.