Hidden within the Grand Canyon are an estimated 1,000 caves. Of those, 335 have been recorded. Very few have been mapped or inventoried. Most have developed in the limestone of the Redwall and Muav formations, although some are known to exist in other formations. Some caves are well known and, over the years, have been frequented often by visitors, such as the Cave of the Domes on Horseshoe Mesa. Cave resources include unique cave formations or "speleothems," mummified remains of extinct Ice Age fauna, archeological remains (including split-twig figurines), and unique biological systems.

Many caves also play a major role in regional hydrology, as evidenced by incredible waterfalls and substantial streams emerging from places like Vaseys Paradise, Cheyava Falls, and Roaring, Thunder, and Tapeats springs. Under the current park policy, all caves are closed to visitation except for research purposes. Please contact John Rihs, Grand Canyon NP Hydrologist for additional information (928) 638-7905.