Kartchner Caverns State Park

Kartchner Caverns State Park near Benson, Arizona, shelters one of the most spectacular living cave systems in North America — a wet, actively forming carbonate cave discovered by cavers Gary Tenquist and Randy Tufts in 1974 and kept secret for 14 years to protect its extraordinary formations. Fearing the fate of other Arizona caves stripped by collectors, the two men spent years negotiating with the Kartchner family landowners before Arizona purchased the land in 1988 and developed the park, which opened in 1999. The cave maintains a constant temperature of 68°F and 99% humidity throughout the year — conditions that keep the formations wet, translucent, and actively growing. The cavern system contains over 13,000 square feet of rooms and passages divided into two main tour areas: the Rotunda and Throne Room, and the Big Room. The Throne Room contains Kubla Khan, one of the world's tallest cave columns at 58 feet, and a dramatic display of soda straw stalactites — hollow formations resembling drinking straws that grow approximately one cubic inch per century. The Big Room, open seasonally from mid-October through April when the cave's resident colony of approximately 1,000 cave myotis bats is absent, houses some of the cave's most extraordinary formations including cave bacon — sheet-like deposits with alternating mineral bands — including a 21-foot specimen that is one of the world's longest. All personal items including cameras, phones, and water bottles must be left in lockers outside the cave; the restriction maintains the humidity that keeps the cave alive and prevents contamination by oils and microorganisms. The airlock entry system ensures the cave's microclimate remains stable.