The cave was used as a mortuary for a brief time by a prehistoric Indian Tribe called the Yokuts. It seems that it was completely forgotten until year 1885. Mercer Caverns are the longest continually operating commercial caverns in the state of California. The owners have guest books signed by paying customers dating all the way back to September of 1885, proving that visitors have been welcome at Mercer Caverns every year since its discovery.
For prices visit Mercer Caverns.