Mallory Cave is a 1.4-mile, moderate hike up into red rock formations of the Boulder Flatirons to a gated cave. Just 40 minutes from Denver, the trail to Mallory Cave was one of the earliest established recreational trails along the Front Range of Colorado. Explore the full trail profile for trail map, driving direcitons, photos, and tips for his hike in Boulder.

Trail Snapshot: Mallory Cave

beginning of mesa trail near NCAR looking toward bear peak and bear canyon on way to mallory cave

Parking & Trailhead Information for Mallory Cave

The National Center for Atmospheric Research (NCAR) Trailhead is located about 40 minutes North of Denver. From Denver, follow U.S. Route 36 to Boulder. Take the exit for Table Mesa Drive and follow it West. It will wind through a neighborhood to the end as it winds through the neighborhood and past Bear Creek Elementary School. The road will turn into the Drive for NCAR which winds up and around to a large parking area at the lab.

The Hike: Mallory Cave

The hike to Mallory Cave begins on the Watler Orr Roberts Trail on the west side of the NCAR parking area. Take the trail west for about 1/2 a mile until it intersects with the Mesa Trail. The Mesa trail runs along the base of the foothills and is the north/south major artery for most of the trails in the Flatirons. For a more detailed trail profile of this southern segment Mesa Trail, check out our South Mesa Trail to Bear Canyon trail profile.

intersection of mesa trail and mallory cave trail in boulder with flatirons in background and trail sign in foreground

Take a left (heading south) onto the Mesa Trail. Soon you’ll encounter the Mallory Cave Trail on your right (west). The Mallory Cave trail is uphill all the way to the cave, becoming more demanding on your legs as it climbs the broad rigde into the Flatirons. You’ll encounter red rock formations along the trailas it makes its way deeper and higher up into the foothills.

keyhole in rock formation along the mallory cave trail hike near boulder

The trail is well-marked, so be alert for signs. The last segment of the hike is a scramble, and one that can be quite dangerous if there is snow, ice, or or water on the rock. Be sure to test the grip of the shoes, just like you might test your braking and tires on your car in snowy or icy weather. And remember, the scramble down is almost always more difficult than the way up. Signage will point you in the right direction (see photo below).

final scramble up granite rock on mallory cave trail

At the cave, you’ll be able to peer into the gated entrance. Why is Mallory Cave Closed? Many caves across the state have been closed because of a strange fungal disease that’s had an adverse impact on the bat populations of Colorado and the West. It appears humans are the ones somehow bringing the disease into the caves. (Cave entrance pictured below).

looking into entrance to mallory cave on hike near boulder colorado

Hike back to NCAR via the same route you took up to Mallory Cave. Give care to your scramble down the slick rock. A final note: we don’t recommend hiking this with your dog because of this final scramble up to the cave.

Tips & Resources for Hiking Mallory Cave

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Map & Driving Directions


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