Up Toward Mallory Cave, Which Boulder Keeps Shut for Bats
A private hike from Boulder's NCAR mesa up a short, steep trail toward Mallory Cave, with the start time set the day before.
The walk starts at the National Center for Atmospheric Research, on a mesa at the west end of Table Mesa Drive, and heads west toward the Flatirons. The city lists it in two pieces. The NCAR Trail runs a mile across a small mesa, drops to a saddle, climbs past a water tank and ends at the Mesa Trail. Mallory Cave Trail leaves that junction and is the part that earns the effort. The city rates it Hard: 0.8 mile and 627 feet of gain on a path one to three feet wide. Ryan and Aylyn, the two guides named on the listing, take one private group at a time.
One booking is a private hike for up to six people, in English, with snacks. The price is USD 300 a person at any group size, and the listing puts the walk at two to three hours.
Private "Boulder Peaks & Wilderness Tours: Mallory Cave Trail"A private guided hike of two to three hours from the NCAR Trail Head toward Mallory Cave, for one group of up to six travelers aged 18 to 65.www.viator.comThe Cave Stays Shut, and the Last Stretch Has a Season
Mallory Cave is closed year-round. The city lists it among the caves closed permanently to reduce the chance of people introducing white-nose syndrome, and its trail page says the cave is closed to protect Townsend's big-eared bats. The listing says it plainly too: the group will not climb into the cave. What changes with the calendar is how close you get. The city closes a buffer around the cave from April 1 to October 1, and its trail page says part of the trail is open only October through March. Between October and March, the city says you can scramble up a solid rock notch to end near the cave entrance. The listing does not say whether the guides take groups up the notch, and the city adds a caution about snow and ice in winter.
Starting at NCAR's Mesa Laboratory
The meeting point is the NCAR Trail Head at 1850 Table Mesa Drive, at the west end of the road. The trailhead sits uphill from the parking lot near the entrance to the center, and the guides wait there holding a sign that reads Mallory Cave Trail Tour. Parking in the lab's visitor lot is free, and the city lists no trailhead fee. Restrooms are inside the NCAR building and open only during its public hours: 8:00 AM to 5:00 PM on weekdays, 9:00 AM to 4:00 PM on weekends and holidays. Along the top portion of the NCAR Trail, the lab has put up a series of interpretive signs about weather.
Two Guides, and a Pace Set by the Group
The listing asks for a high level of physical fitness, and marks the hike as not recommended for travelers with spinal injuries, poor cardiovascular health, or a pregnancy. Several travelers who have written about the hike describe a guide who matches the group's pace. One hiker in October 2024 called it beautiful and challenging, and wrote that Ryan adjusted the hike to match their hiking ability. Another, who had lived in Boulder for years, expected it to be longer and more strenuous than it turned out.
Ages, Start Times and Weather
Only travelers aged 18 to 65 can be booked; the listing offers no other age band. A message arrives the day before the hike to set the start time around the weather, and summer hikes leave at 9:00 AM unless the guides say otherwise. A full refund needs a cancellation at least 24 hours before the start; inside that window the listing refunds nothing. The booking terms also allow the hike to be called off for poor weather or too few travelers. Snacks are the only inclusion listed. Carry your own water.
One hiker wrote of not being ready to wrap up even back in the parking lot. Another, new to Boulder, left with directions to more of the city's trails.