The "Balanced Rock" at Arches National Park

According to the National Park Service, "Balanced Rock clearly shows the various layers responsible for this amazing defiance of gravity. The caprock of the hard Slick Rock Member of the Entrada Sandstone is perched upon a pedestal of mudstone. This softer Dewey Bridge Member of the Carmel Formation weathers more quickly than the resistant rock above. Eventually, the faster-eroding Dewey Bridge will cause the collapse of Balanced Rock."