Bats keep half of this California cave closed most of the year, and right now you can walk all of it
The best mile and a half in Pinnacles National Park happens mostly in the dark. Bear Gulch Cave is a jumble of house-sized boulders jammed into a narrow canyon, and you climb right through the gaps between them on old stone stairs, flashlight in hand.
Here’s the catch: for most of the year, half of it is off-limits. A colony of bats calls this cave home, and the upper section only opens to hikers in short windows each spring and fall. As of the park’s latest update, the whole thing is open right now.
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Why the bats get the final say
Several hundred Townsend’s big-eared bats live in Bear Gulch Cave, and the Park Service calls it the largest known colony between San Francisco and the Mexican border. They roost on the walls and ceilings of the cave’s bigger rooms, which makes them especially sensitive to people tromping through.
So the schedule bends around them. The entire cave closes from roughly mid-May to mid-July while the mothers raise their pups, then only the lower half reopens. From November through February, when the bats hunker down for winter, it’s lower half only again.
That leaves March and October as the months when the upper cave usually opens, sometimes for just the last week and sometimes for the whole month. This year, the park’s October 1 update already listed both sections as open.
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What it’s actually like inside
Forget the dripping limestone caverns you might be picturing. This is a talus cave, formed when chunks of fractured volcanic cliff broke loose, tumbled into the canyon, and wedged together, leaving passages in the gaps.
In the 1930s, the Civilian Conservation Corps built the stairways and bridges that let you walk through without ropes or ladders, and they’ve held up through decades of storms. Expect a lot of stone steps, ceilings low enough to make you duck, and a few tight squeezes where you’ll be glad you didn’t wear your biggest backpack.
Some stretches are pitch black, so a headlamp or flashlight is a must. Water can run through the bottom of the cave at certain times of year, so wear shoes with real grip, keep your voice low, and keep your light off any bats you spot.
The loop, by the numbers
The classic route is the Moses Spring to Rim Trail loop out of the Bear Gulch area. Depending on where you park, it runs about 1.3 to 2.2 miles round trip with roughly 400 to 500 feet of climbing, and it’s rated moderate.
The Park Service figures an hour to an hour and a half, though you’ll probably spend extra time just staring up at the boulders overhead. The trailhead lot at the end of the road is small, so get there early. Not into caves? A bypass trail skips the dark parts and still gets you to the top.
The payoff at the top
Climb out of the last dark stretch and you pop out at Bear Gulch Reservoir, a small lake held back by a dam the Civilian Conservation Corps finished in 1935. Rock spires ring the water, and it’s the perfect spot to sit on a boulder and let your eyes readjust to daylight.
The reservoir doubles as habitat for the California red-legged frog, a threatened species in the state, so admire it from the rocks. Then loop back on the Rim Trail for views out over the eastern hills.
Got more energy in the tank? Our guide to the best hikes in Pinnacles National Park covers the bigger routes, including the climb up into the High Peaks.
Plan around the calendar
Pinnacles is a national park, so entry is $30 per private vehicle and good for up to seven days, or free with an America the Beautiful Pass. Cell service is limited in the park, so buy your pass and save it to your phone before you arrive.
Starting November 1, the park typically keeps only the lower half of the cave open for the bats’ winter season, and the schedule can shift with the weather. Check the park’s cave status page before you make the drive.
So, would you squeeze through a bat cave for a lakeside snack break? We’d do it again in a heartbeat, maybe with a brighter headlamp this time. Tell us your favorite Pinnacles trail!
Trip tips: grab a rental car to get out here, lock in your hotel before the good rooms are gone, or skip both and book a camper van instead.
Rules and fees change, so always confirm current requirements before you go.
