Bear Cave is the only cavern in the Great Lakes area. Formed in rare "tufa rock" (a secondary limestone) this particular bed is estimated by geologists to be at least 25,000 years old, and rests on a glacial drift deposited during the last ice age 50,000 years ago. Beautiful stalactites, flowstone, petrified leaves, and strange shapes, all delicately colored by the metal oxides of native ores, are present throughout the cave. In 1875, the "goods" from an Ohio bank robbery were hidden in the ca ve. Inspired by this event, Bear Cave was featured in the 1903 movie The Great Train Robbery -- now considered a silent film classic, and the forerunner of the thriller movies of today. Outside, the area surrounding Bear Cave is rich in wooded hills, wildflowers, deep ravines, and of course, the magnificent St. Joseph River.