Coronado Cave became part of Coronado National Memorial in 1978 when the park expanded its boundaries. The cave may have been used by humans as a shelter and hideout by middle archaic people (up to 8000 years ago) and more recently by the Chiricahua Apache and other Apache peoples, Mexican and European miners, and settlers (however, no archaeological evidence remains in the cave today). The cave is now one of the few open, undeveloped caves in southern Arizona. Coronado Cave is a large cavern 600 feet long and in most places about 70 feet wide.