Geologic Trip, Sequoia NP
The entrance to Crystal Cave is just above Cascade Creek, which lies at the lower left. The cave is open to the public and is the most popular cave in Sequoia National Park. The cave is in a bed of marble that forms a 700-foot wide ridge between nearby Yucca Creek and Cascade Creek. The cave was formed by water that flowed from Yucca Creek into a pit in the floor of the creek. From the pit, the water flowed through a series of sub-horizontal joints in the marble until it emerged on the other side of the ridge and flowed into Cascade Creek. As the water followed these joints, the weak acid in the water dissolved the marble along the joints to form the cave.