Carlsbad Caverns - natural entrance to Carlsbad Caverns

Historic natural entrance to Carlsbad Caverns. The viewing area near the entrance is crowded on summer evenings when clouds of bats exit the cave. The caverns formed in reef-tract limestones (the Capitan Reef complex) that were deposited in an ancient sea during Permian Period (NPS, 2010b). The Permian Period extended from about 299 to 251 million years ago. The Capitan Reef complex is exposed throughout the southern Guadalupe Mountains in Texas and New Mexico.