Numerous formations in the Flatirons are closed to climbing every year from February 1 – July 31 to protect birds of prey. The closures have been in place for decades and have helped falcons, eagles, bats and other bird species reproduce and raise young without disruption and restore populations. The formations are monitored for nesting activity by OSMP staff and volunteers and closures dates may change. Trails can also be closed for construction and repairs, which may affect access to climbing formations.

Bear Canyon trail closure because of Xcel transmission line work – updated August 28, 2018

The Bear Canyon Trail west of the Mesa Trail is closed 24 hours a day and is expected to continue through November, weather permitting.  This affects Overhang Rock and other formations accessed from Bear Canyon.  Other trail closures and intermittent trail closures will occur on trails in the project area; details can be found at

The specific trail closures include:

  • September 4 to December 1: The NCAR-Table Mesa/Bear Trail will be closed because of Xcel electric construction work. The NCAR-Bear Connector Trail may see intermittent, full-day closures because of this work.
  • September 5 and September 6: The NCAR-Bear Canyon Trail, the NCAR-Bear Connector – along with a Mesa Trail section from NCAR to Fern Canyon – will be closed because of Xcel-related electric work.
  • Mid-September through Mid-November: The NCAR-Bear Canyon Trail between Stony Hill Road west to NCAR-Bear Connector will be closed 8 a.m. to 5 p.m. Monday through Friday. This closure will help OSMP complete some of the department’s final 2013 flood-recovery work to repair trails and restore wildlife and plant habitats in the area.

As of mid-August, 2018, the following formations are now open for climbing through January 31, 2019:

  • Mount Sanitas Summitsouth of the Mt. Sanitas East Ridge Trail, east of Mt. Sanitas Trail (both trails remain open)
  • Skunk Canyonincluding Ridges 2, 3 and 4, the Aechean Pronouncement, the Dreadnaught, the North Ridge and the entirety of Sacred Cliffs.
  • Der Freischutz, Frankenstein’s Castle, The Bubble, Der Freischutz, Southern Dinosaur Egg, Northern Dinosaur Egg and  Dinosaur Rock.
  • Bear Creek Spire: north of Bear Canyon Trail (the designated Bear Canyon hiking trail remains open).
  • The Kolb, Weiser and ERTL Properties east of 75th Street and north of Valmont Road.
  • Lefthand Canyon Palisades, at the intersection of Lefthand Canyon Drive and Olde Stage Road (Buckingham Picnic area remains open).
  • Flagstaff Mountain, the north side of Flagstaff Mountain.
  • The Back Porch and The Box.
  • Fern Canyonnorth of the Fern Canyon Trail, including the Nebel Horn Ridge, East Ridge, the Goose and the Goose Eggs (the designated Fern Canyon hiking trail remains open).
  • Shadow Canyon, the Matron and The Wings, the Maiden remains open and accessible from the east; Shadow Canyon Trail remains open
  • The entire Mickey Mouse wall, including South Tower, Industrial Wall, North Tower, Central Tower, Ship’s Prow, Wall of Shiva’s Dance, The Gargoyle, the East Face and Cryptic Crags.
  • Third Flatiron, including the Queen Anne’s Head, W.C Fields Pinnacle, 1911 Gully and the Ghetto, the East Bench & West Bench, the East & West Ironing Boards, The Fin, Green Thumb and Jaws.

Information on OSMP wildlife closures, which help to protect sensitive habitats, can be viewed at

For a complete list of trail and raptor closures and the most up-to-date information, please visit the OSMP sites: