FAQs

So many questions come to mind when exploring the underground world of the world's longest cave system. Below are some of the most common questions posed to park rangers at Mammoth Cave, according to the National Park Service: **Do you still offer a boat tour inside the cave?** No. The Echo River Tour was discontinued in the early 1990s because human traffic in the river was causing harm to aquatic creatures that live there. Also, keeping the passages, which flood frequently, open for the public was prohibitively expensive. In season, we do offer the River Styx Tour, which lets visitors get a glimpse of the underground rivers. Check cave tour schedules for availability. **How strict are the age and size limits?** Some tours have limits on the age and size of participants. These restrictions have been established for your safety and to ensure that we are able to offer a quality interpretive experience. The limits are, therefore, strictly enforced. In some cases, proof of age may be required before a person will be permitted to purchase a ticket. **What tour do you recommend?** Mammoth Cave National Park offers a number of tours, most of which are quite different from one another, and which place different demands on visitors. For your first visit to Mammoth Cave, the Historic Tour or the Domes and Dripstones Tour are good options. If you only have a little time, we recommend the self-guiding Discovery Tour (in season). **Is it all right for me to write my name on the cave wall?** No. You can, unfortunately, see where uncaring and insensitive people have done so in the past, and it does not improve the appearance of the cave. Such vandalism is very hard to clean up. **How old is Mammoth Cave?** Geologists estimate that the oldest part of Mammoth Cave began forming around 10 million years ago. **Can Mammoth Cave turn into a volcano or a canyon?** Volcanoes are caused when molten rock from below the Earth's crust is forced upward through the crust. Although some caves called "lava tubes" are produced from the action of molten lava, Mammoth Cave is not one of these. There is no volcanic activity in the region. Eventually, thousands of years in the future, Mammoth Cave will erode into a series of canyons. But none of us will be around to see them. **Does Mammoth Cave draw big crowds?** On our busiest summer days, between 5,000 and 7,000 visitors come to the park. In a year, more than two million visitors come to the park, with nearly 500,000 of them taking a cave tour. **How long is Mammoth Cave?** To date, explorers have mapped and surveyed more than 390 miles of cave passage, making Mammoth Cave by far the longest known cave system in the world. The explorers are still discovering new passages, and they often say that "there is no end in sight." **How was the cave formed?** An ancient sea that covered the central United States 325 million years ago laid down over 600 feet of soluble limestone here, which was then covered by a sandstone and shale cap deposited by an ancient river. The sea and the river disappeared, and erosional forces worked through the cap until about 10 million years ago, when cracks and holes began to expose the limestone underneath. Rainwater made its way underground in the form of sinking streams, which began hollowing out the cave as underground rivers. **Why is the cave called "Mammoth Cave"?** The name "Mammoth" was first used to describe the cave in the early 1800s. It refers to the "mammoth" size of the cave's chambers and avenues, not the prehistoric, elephant-like mammal. **Are there endangered animals and plants in the park?** The park contains several species of endangered plants and animals, including Eggert's Sunflower, the Eyeless Cave Shrimp, and several species of river mussels, among others. **When was the park established?** July 1, 1941. **Why was the park established?** The Park was established to preserve the cave system, including Mammoth Cave, the scenic river valleys of the Green and Nolin rivers, and a section of south-central Kentucky's hill country.