This cave was discovered in 1974 by two cavers from Tucson. Knowing how fragile cave environments can be they kept it a secret for 14 years, telling only the owners of the property under which the cave lay.
Finally in 1988, after cloak-and-dagger dealings that even involved bringing people to the site blindfolded (interesting details here: http://explorethecaverns.com/caverns-history.html), arrangements were made to turn it into an Arizona state park, and after still more years of preparation the caverns were finally opened to the public in 2003.
Kartchner is a “living” cave, meaning that water still seeps through it and formations are still growing. Part of the preparation for opening it to the public was installing double-airlock doors to keep out the dry hot desert air in order to maintain the near 100% humidity inside.
Normally, photography isn't allowed on tours, but occasionally there is a special tour where people can bring cameras and tripods.