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Boulder, CO 80306
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Trail Closures

Area Closure and Condition Updates

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.

Click here for more information:

Trail closures, advisories and fire bans
Seasonal leash restrictions
Seasonal grassland ground nesting bird closures
Seasonal Bat roosting site closures
Seasonal Raptor closures
Mud snail closures
Overview Map of Seasonal Wildlife Closures 443.34 Kb -updated 06/01/09

Trail advisories:

OSMP to burn ditches throughout winter months
Starting the week of January 9, 2009, OSMP, in conjunction with the Boulder Fire Department, will be conducting ditch burns throughout the winter months on the city’s agricultural properties. Burning is weather dependent, and no burning will occur on Red Air Quality days. Trained Fire Department personnel will be on site during this activity as well as natural resource advisors.

Boulder Falls temporarily closed March 30, 2009
Boulder Falls remains closed indefinitely, due to the danger of continuing rock falls in the area. Boulder Falls is located 11 miles west of Boulder on the north side of Canyon Boulevard (SR119) between Boulder and Nederland. The falls can be safely viewed from State Highway 119's right-of-way. No Trespassing signs have been posted in the area.

Hidden Valley Trail reopened November 6, 2009
The Hidden Valley Trail had previously been closed following an incident in which an open space visitor reported rounds from a nearby shooting range coming near where they were hiking. An investigation by OSMP and the City of Boulder’s Risk Management Office found that while possible, the likelihood of someone being struck by a stray bullet was extremely unlikely. They visited the shooting range, which is privately run, and not on open space land, and found that its operations and safety procedures were appropriate. Nonetheless, OSMP will post warning signs on the trail informing users that visitors have reported rounds coming near them and that there may be a risk.

Work on Flatirons Vista North trail beginning November 9, 2009

OSMP's trails group will be working on the Flatirons Vista North trail beginning Nov. 9, 2009. At this time, no trail closures are anticipated, but there will be equipment and materials around and the full surface of the trail might not be available. OSMP hopes to have the work completed by Nov. 20, 2009.

Prescribed burn and temporary trail closure Wednesday, September 16, 2009 - burn area closed.

OSMP and the Boulder Fire Department, in conjunction with other local fire agencies, conducted a prescribed burn on Shanahan Ridge on Sept. 16, 2009. The area burned is located east of the Mesa Trail and south of the Shanahan – South Fork Trail, and will remain closed until the area is safe for pedestrian travel. Signs will be hung at the burn site as well as in the trailhead boards in Shanahan Ridge, and on trail posts near the burn. The Shanahan – South Fork Trail was closed during the burn, but is now open. Map of closed burn area pdf

No parking along Highway 170 near Doudy Draw and South Mesa Trailheads

Please remember that parking is not allowed on Highway 170 at any time.

Social Trail Restoration

Efforts are underway in the Eldorado/Doudy Draw and Marshall Mesa/Southern Grassland areas to restore social trails. Please observe the "Keep off the trail" signs and avoid traveling on these social trails and eroded sites that are being restored. "Social trails" are often unsustainable and result in the trampling of fragile vegetation, soil compaction and erosion and disturbance to wildlife.

Wildland Restoration Volunteers working in Eldorado/Doudy Draw
Click here to see more photos of the project!

Seasonal leash restrictions

Dogs must be on leash from August 15 through November 1 on the following trails:

Portions of Gregory Canyon, Saddle Rock and Amphitheater Trails 2.33 Mb
Skunk Canyon up to the Mesa Trail 2.23 Mb
Upper Big Bluestem Trail 345.27 Kb
Portions of the Doudy Draw Trail 257.93 Kb

Dogs must be on leash at Lower Big Bluestem May 15 through July 15 for seasonal grassland ground nesting birds.

Seasonal Grassland ground nesting bird closures in effect May 1 through July 31

Dogs must be on leash at Lower Big Bluestem May 15 through July 15.

The following areas will be closed for the protection of grassland ground nesting birds from May 1 to July 31:

both sides of the Greenbelt Plateau Trail from Community Ditch trail to Highway 128. Dogs will be allowed on the Greenbelt Plateau Trail only if they are on-leash (area is normally voice and sight control);
Community Ditch Trail west of Highway 93 and north of Community Ditch Trail;
west of Highway 93 and north of Doudy Draw Trail.

baby_grsp2

Grasshopper sparrow nestlings

pdf Map grassland bird closures 2.16 Mb

Seasonal Bat roosting site closures in effect April 1

OSMP closes Mallory and Harmon Caves, accessible from NCAR trailhead at the end of Table Mesa Road from April 1 to October 1 of every year. They are closed to protect Townsend's Big Eared bats. OSMP also closes the east face of Der Zerkle rock formation, accessible from the NCAR trailhead from April 1 to September 1 to protect the roosting sites of Fringed Myotis bats.

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 seasonal closures help ensure they will remain undisturbed by humans during roosting season.
Thank you for your cooperation!

mallory-clos

Mallory Cave - closed April 1 - Oct. 1

harmon

Harmon Cave - closed April 1 - Oct. 1

der-zerk

Der Zerkle East Face - closed April 1 - Sept. 1

Seasonal Raptor closures:

Please help us protect wildlife by:

Photo - Prairie falcon

Respecting all area closures.

Immediately leaving any closure area should you accidentally enter one.

Urging cooperative respect for closures from fellow park users.

Municipal fines are up to $1,000 and jail time up to 90 days.

Final 2009 Raptor Report

Final 2008 Raptor Report

Follow this link to meet some of the animals protected by these closures. golden_nest

Bald Eagle nesting closures run from Nov. 1 until July 31.

Cliff Nesting Raptors are protected from Feb. 1 through July 31.

Burrowing Owls are protected March 15 through Oct. 31.

Osprey

are protected March 15 through Sept. 10.

Bald Eagles:

Kolb and Coal Creek Property Closure:

OSMP closes the Kolb property in the White Rocks area (near 75th and Valmont) and the Coal Creek Property (east of Hwy 93 and near Marshall Lake) temporarily between Nov. 1 and July 31 to protect bald eagle nesting and roosting activity.

Coal Creek Closure

Kolb Property Closure

Cliff Nesting Raptors:

Overview Map of OSMP: This map shows all of the cliff nesting raptor closures.

The following areas are closed every year from Feb. 1 - July 31 to protect cliff nesting raptors:

Back Porch-Skunk Canyon.

Lefthand Canyon Palisades.

Flagstaff North: The north side of the Flagstaff Mountain Summit.

Mt. Sanitas Ridge --1st Buttress Only.

Gregory Canyon Amphitheater: Amphitheater Express Trail and the 3rd Pinnacle are closed. The 4th and 5th Pinnacles and the Amphitheater Trail to Saddle Rock remain open.

Skunk Canyon and Sacred Cliffs: Skunk Canyon, Ridge 2 and all areas west of Ridge 2; Sacred Cliffs, south rib of Green Mountain are closed.

North side of Fern Canyon: (Fern Canyon Trail is open): East Ridge, Nebel Horn Ridge, The Goose, Goose Eggs are closed.

The entire Third Flatiron: all routes, including: The Descent Trail, Queen Anne's Head, W.C. Field's Pinnacle, 1911 Gully, The Ghetto, The East and West Ironing Boards, The Fin, Green Thumb, and Jaws are closed.

Shadow Canyon: The Matron: all areas within 1/4 mile radius, the entire Devil's Thumb Ridge, Towers of the Moon, Elephant Rock, Jamcrack Spire and Diamond Head are closed. The Maiden is OPEN to climbing with access from the EAST side only.

Mickey Mouse Wall: all routes are closed.

Burrowing Owls:

These areas are closed to protect nesting burrowing owls every year from March 15 - Oct. 31:

Kelsall Burrowing Owl

Walker Burrowing Owl

Damyonovich/Yunker Burrowing Owl

Jafay/Lynch Burrowing Owl

Aweida Burrowing Owl - closure lifted May 27, 2009 - Burrowing owls are not using this area this year.

Axelson Burrowing Owl - closure lifted May 27, 2009 - Burrowing owls are not using this area this year.

Osprey:

The Axelson area near the Boulder Reservoir is closed to protect nesting Osprey every year from March 15 - Sept. 10:

Axelson Osprey

New Zealand Mudsnails:

Boulder Creek closure to all access for New Zealand Mudsnails