Over 50 smaller streams contained in 18+ miles of known passages combine in the main river passage to create America's longest navigable underground river. Living in the miles of flowing streams are rare blind cavefish and blind crayfish. Passengers on the custom electric tour boats can usually sight some of these unusual creatures as they float though the winding passages.
California Cavern, State Historic Landmark
In 1849 or 1850, Captain Joseph Taylor was target shooting on a rocky outcropping and noticed that his targets were being moved by a breeze which seemed to emanate from the rocks. When he investigated this curious phenomenon, he discovered the entrance to a cave which he named Mammoth Cave.