Lehman Caves – Great Basin National Park
The Lehman Cave system began forming approximately 550 million years ago (during the Cambrian) while it was still submerged in a relatively warm, shallow ocean. The caves are made up of a marble and limestone solution, for the most part, that forms the many cave decorations throughout the caverns.
The cave system became much deeper during the Pleistocene, when a prolonged and increased flow of water eroded through the cave’s fracturing bedrock. Eventually, the water level dropped, leaving glare rooms and cavities in the rock, creating the depths of the Lehman Caves system.
