In the heart of the cascade rocks of the Yakima’s Basalt Formations, lives Boulder Cave. It took millions of years of volcanic action to create the Basalt rock formations, and thousands of years of erosion and weathering to develop boulder cave. Over a long process, layers of basalt rocks formed through a series of lava flows and inter-flows. Hot layers of lava cooled over softer layers of loose rocks and soil. For thousands of years the now existing cave has been eroded by the water from Devils Creek pushing its way through the layers of hard Basalt rock and gradually taking away the softer layers of rock that laid in between. Around 25,000 years ago,The stream created an archway of 350 ft. long and 30 ft. wide. This amazing cave was finally discovered on August 2, 1901 by some prospectors in the area.
Boulder Cave is home to the Pacific Western big-eared bat species (a.k.a. Townsend bats), which is listed as a sensitive species in both Washington and Oregon. The populations in boulder cave was estimated to be in the thousands during the 1920s and 30s, but it’s now down to only about fifty, due to the increase of the public use. They no longer tend to stay inside the cave during the warm seasons, for they are intolerable to human disturbances. The big-eared bats use the cave as a Hibernaculum to survive the winter. Therefore, the cave is closed from October 1 to May 1 to reduce the disturbance of the bats. The big-eared bats play an important role in the forest ecosystem. They prey on insects and moths which can defoliate parts of the forest.
The Boulder Cave Trail was built by the Civilian Conservation Corps (CCC) in 1935. It was improved once in 1987 by the Youth Conservation Corps (YCC), and the voluntary help of a local stone mason.
This gravel covered trail slopes upward slowly from the parking area through the edge of a small gorge in the deep ravine where the Devil Creek flows. The path follows through Ponderosa-pine and Douglas-fir forest, there are also some old maples and alders that can be found. About 400ft before the cave entrance, the trail narrows to reach the split opening of the rock near the cave mouth. It usually should take about a hour of hiking to finish this trail.
Use your light on the path and not at the ceiling while in the cave to avoid disturbing the bats!
Try to keep it quiet to prevent disturbing the living creatures inside the cave!
Do not start campfire and do not spend more than enough time inside the cave!
Stay away from shortcuts to prevent causing erosion and impact.
Stay on the trail and dont not double back.
From Naches Washington drive North West on Highway 12 about 4.2 miles and stay left at junction which turns into State Route 410 follow about 18 miles. Route 410 is washed out, follow well marked detours. Back on State Route 410, drive pass Whistling Jacks lodge, about 1.5 miles and turn left onto a road signed “Boulder Cave National Recreational Trail.” Cross the Naches River on a bridge and almost immediately turn right, following the signs 1.1 miles to the trailhead.
Connecting trails: Boulder Barrier Free trail
Distance: 1.5 miles
Max & min elevation: 2750 ft. – 2450 ft.
Elevation change: 300 ft.
Level of Difficulty: Easy
Best Seasons: Spring/Summer/Fall
Current Trail Conditions: Maintained
Park/Forest: Okanogan and Wenatchee National Forests
Permits/Reservations: yes – no, $5 at the entrance
Campsites: No Camping
Toilet Facilities: Yes, Modern
Water Sources: Yes, Modern
Best time to visit:
The trail head and the park grounds are organized for day use only. It usually opens on Memorial Day weekend and closes shortly after Labor Day. But you still need to check with the Naches Ranger Station for confirmation during spring and fall.
The area is managed by the Forest Service, and there is a $5 parking fee for each vehicle. Except for owners of a Northwest Forest Pass, National Parks and Federal Recreational Lands Pass and Interagency Senior/Access passes.
Things to pack with you:
Layered clothing even during the summer time
Proper walking shoes
Bright headlamp and/or strong flashlights
This map was made from a Google Earth KML file, and is only a representation, it is not 100% accurate! .
Submit a GPX file from your G.P.S. device and make it accurate.