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. It was named after a University of Colorado student, Mallory Largent, who was the first to explore and map the cave in the late 1800s.
Nestled in the base of the Flatirons, Mallory Cave is home to Townsend’s big-eared bat, one of the more exotic-looking flying mammals. The bats are seasonal inhabitants of the caves, and only 1 of 11 colonies exist in Colorado. They are extremely important to the ecosystem and provide much-needed pest control. Due to an outbreak of white-nosed syndrome, a fatal fungal infection to bats, Boulder permanently closed the entrance to the cave in 2011 but it’s still worth a visit to see the fancy iron gate that was installed to give the bats their privacy. And truth be told, the cave itself was only a few dozen feet beyond the gate, so hikers aren’t missing much by not accessing the shallow cave proper.
The quickest way to access Mallory Cave is from the parking area at the National Center for Atmospheric Research. Hikers can make a longer day by accessing the Mesa Trail from Chautauqua Park as well. From NCAR the trail is only 2.8 miles round trip out and back but gains a stiff 940 ft. of elevation along the way. Despite the short length, the hike up through the vanilla-scented pine forests and ancient rock structures makes this an incredibly scenic adventure. The shady switchbacks traverse over twisted, gnarled roots and through cracked boulders. Along the way are several climbers’ paths that lead to popular rock climbing areas which are nice places for climbers and boulderers to play and escape the sun on hot summer days.
There is a little bit of signage on the way up, though the trail can get a little tricky to follow due to offshoots. To stay the course, just maintain the widest, most worn path. Make sure to turn back and take in the east-facing views of Boulder, Boulder County from time to time. The last segment of the hike is a scramble and one that can be quite dangerous if there is snow, ice, 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. This flat section is also marked with a sign that has information about the local bats. A 50-foot scramble to the gate will require hands and feet so consider this before letting small children or less-athletic dogs make the climb to the gate because the hard part isn’t getting up, it’s getting down.
You’ll see breathtaking views of NCAR, Boulder, and the eastern plains as you reach the cave’s summit. It may appear “used,” but people continue to marvel at the cave as one of Boulder’s earliest recorded front range hikes.