Mallory Cave, Chautauqua Park Trailhead, Boulder - Denver - Golden - Fort Collins - Lyons, Colorado

Mallory Cave - 5.4 miles

Chautauqua Park Trailhead

A steep rock wall must be scaled to reach Mallory Cave

A steep rock wall must be scaled to reach Mallory Cave

Round-Trip Length: 5.4 miles
Start-End Elevation: 5,710' - 6,825' (6,825' max elevation)
Elevation Change: +1,115' net elevation gain (+1,285' total roundtrip elevation gain)
Skill Level: Moderate
Dogs Allowed: Yes
Bikes Allowed: No
Horses Allowed: No
Related Trails:

Mallory Cave - 5.4 Miles Round-Trip

Note: Mallory Cave is closed until further notice. The trail remains open, however, the cave itself is not open to the public. The closure stems from an epidemic of white-nosed syndrome, a fungal disease that has destroyed bat populations across the country.  

The U.S. Forest Service closed all caves on National Grassland and Forest properties across several states to limit the potential for spread in the Western region. Because the disease is primarily found in human-accessible recreational caves, people are thought to be the main cause of spreading.

Mallory Cave was first discovered, but not recorded, by loggers cutting down trees on Dinosaur Mountain in the early 1900s. The cave, only a rumor at the time, was 'rediscovered' by University of Colorado Student E.C. Mallory in the summer of 1932.
Mallory Cave is of modest size and lacks the stalagmites and stalactites one might expect, however the cave is of special importance to Fringed Myotis and Townsend's Big Eared bats, whose maternity colonies roost here between April and October.
Mallory Cave can be reached from either the Walter Orr Roberts Trail at NCAR, or the Mesa Trail beginning in Chautauqua Park. The former is short and direct, while the latter is longer but arguably more scenic, passing Boulder's iconic Flatirons and more varied terrain en route to the Mallory Cave split.
The following describes the Chautauqua Park - Mesa Trail - Mallory Cave Trail route:
From Chautauqua Park, head south on Blue Bell Road to the Mesa Trail (.6 miles : 6,010). Bear left and begin a steady climb through tall ponderosa stands to the Kohler Mesa Trail split (1.15 miles : 6,250'). The Mesa Trail levels across open contours with good views of the eastern plains.

It dips and rises past the Skunk Canyon Trail junction to a steep, twisting descent on reinforced mud-stairs (1.85 miles). Once down the trail rises across open slopes with good views of Bear Peak to the Mallory Cave Trail junction (2.05 miles : 6,207').

Travel steepens on a rocky climb up the heavily wooded north flank of Dinosaur Mountain. You'll come to a helpful trail marker in 2.5 miles (6,490'), past which it tightens on switchbacks through dense pine and large rock formations.

Pass consecutive spurs for Der Zerkle Climbing access (2.55 miles), squeeze through a slot between two boulders (2.6 miles ) and skip by the Upper Dinosaur Mountain climbing access spur (2.65 miles) to the vertical rock base of Mallory Cave (2.7 miles : 6,810').

Here interpretive signs discuss the life cycles and migratory patterns of Townsend's Big Eared and Fringed Myotis bats, which rely on this cave and surrounding rock crevices for protection of their maternity colonies.

The rock face must be scaled to see and enter the cave (currently not open to the public). Confident climbers and scramblers will have little trouble with this knobby 30' wall, but those unfit may opt for additional aid. Snow and ice can present serious challenges for any skill level; exercise patience and good judgment before embarking on the entry climb.

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Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N39 59.930 W105 16.970 — 0.0 miles : Chautauqua Park Trailhead
  • N39 59.496 W105 17.119 — .6 miles : Bluebell Road - Mesa Trail junction
  • N39 59.126 W105 17.157 — 1.15 miles : Mesa Trail - Kohler Mesa Trail junction
  • N39 58.677 W105 17.055 — 2.05 miles : Mesa Trail - Mallory Cave Trail junction
  • N39 58.421 W105 17.236 — 2.5 miles : Mallory Cave Trail sign
  • N39 58.455 W105 17.354 — 2.65 miles : Base of Mallory Cave

Worth Noting

  • Mallory Cave is closed April 1st - October 1st every year, unless otherwise posted by the City of Boulder's Open Space and Mountain Parks Division. During this time you may hike to its base, but not scale the rock wall leading into the cave.

  • Honor seasonal closures and do not disturb roosting bat colonies. Entering Mallory Cave when closed is punishable with fines and/or jail time.

  • The Townsends's Big Eared Bat maternity colony on Open Space and Mountain Parks Property is one of only seven known colonies in the state of Colorado.

  • Parking is limited at the Chautauqua Park Trailhead and spaces fill up quickly. Street parking restrictions are enforced.

Rules and Regulations

  • Mallory Cave is closed to the public to help prevent the spread of white-nosed syndrome. Please honor travel and access restrictions in the cave vicinity.

Directions to Trailhead

From Boulder:
Take Baseline Road 1 mile west to the Chautauqua Park entrance on the left hand side.

From Denver:
Take Highway 36 into Boulder and exit on Baseline Road. Turn left. Take Baseline Road to the Chautauqua Park entrance on your left.

Contact Information

City of Boulder Open Space and Mountain Parks
Phone: 303.441.3440

Trip Reports

There are no trip reports on this trail.


"This cave is closed year-round now, and gates will stop you from reaching it. See OSMP website for closures."
Chris  -  Boulder  -  Date Posted: September 16, 2012
"You are not supposed to go near the caves at all. There are signs that say the area is permanently closed due to white nose syndrome. We stopped at the signs, though I saw a lot of people going on. The signs need to be bigger - I don't think many people saw the word closed."
Denise  -  Mead, CO  -  Date Posted: April 2, 2012


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