Hoping to protect the cave from vandalism, they kept the location a secret for 14 years, deciding that the best way to preserve the cavern — which was near a freeway — was to develop it as a tour cave. After gaining the cooperation of the Kartchner family and working with them for ten years, together they approached the Arizona State Parks Board. In 1985, The Nature Conservancy acquired an option to purchase the land. The discovery of the cave was finally made public in 1988 when the landowners sold the area to the state for development as a park and show cavern. Prior to its grand opening in 1999, the state spent $28 million on a high-tech system of air-lock doors, misting machines and other equipment designed to preserve the cave.