AAA Editor Notes
Boulder Cave is just off SR-410 between Mt. Rainier National Park and the junction with US-12. Watch for the sign on SR-410 just w. of Cliffdell; cross the bridge, turn right and proceed 1.4 mi. to the parking area.
This unusual cave was formed some 25,000 years ago when a stream eroded through loose sediment and ash deposited between layers of more resistant lava. The passageway is about 400 feet long and 30 feet wide. From the parking area, a .75-mile interpretive trail ascends a gradual slope through open woodland of Douglas fir, ponderosa pine and Western larch to the cave entrance. En route is an observation platform overlooking Devils Creek, which flows through a deep ravine. From the cave exit, a short trail climbs steeply up to the main trail on the rim of the ravine.
Bring a good light source in order to safely negotiate the cave.
Guided tours are available. Picnicking is permitted.