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Mammoth Cave National Park
Washington National Parks

Mammoth Cave National Park

An International Biosphere Reserve

Western Kentucky is known as the land of a thousand sinkholes, with Mammoth National Park being at the center. This 53,000 acre wildlife preserve is just part of the huge forest that once spread over most of eastern and central North America. On the surface the land is beautiful rolling hills and tall trees, but below lies a mysterious world of tight spaces, grand rooms and elegant formations.

Frozen Niagra Passage © Carla Suson /
The Frozen Niagara Tour and the Great Onyx Lantern Tour specifically include wet cave formations of soda straws and flowstone.

How the Caves Were Formed

The Kentucky area was a shallow sea 350 million years ago. As the water dropped, the land evolved into layers of sandstone on top and limestone underneath, creating unique conditions for cave formation. Underground rivers carved the passages, and the larger rooms were formed by whirlpools as the water levels steadily dropped over 70 million years. The underground river still exists 450 feet below the surface, emptying into the Green River.

The millions of years' water action left 350 miles of explored territory and potentially another 600 miles of undiscovered areas, which are the habitat of 130 cave life forms including crickets, fish and bats. Most of the caves are dry now and lack the stalactite and stalagmite formations often seen in wet caves. Most of the current park tours feature enormous rooms and elegant water-carved passageways. However, the Frozen Niagara Tour and the Great Onyx Lantern Tour specifically include wet cave formations of soda straws and flowstone.

Area History

Aboriginal artifacts, dating back 2,000 to 4,000 years, were discovered in some of the areas, indicating that early man may have lived in the cave entrances and mined for salt.

Early settlers came to the area in 1798 and mined saltpeter (needed for gunpowder) during the War of 1812. After the war, the mining interest died out but word of the huge cave system spread to the larger cities. Thus, by 1816, Mammoth Caves had become one of the first American tourist attractions. Early visitors attired in fancy dresses and stiff suits walked through the caves using rickety ladders and dim lanterns. They often carved their names and dates in the rocks with chisels or lamp smoke. Those signatures are still visible today on the some of the tours, although the practice was stopped many years ago.

Mammoth Caves was one of the first areas to join the national park system, in 1916, with only 40 miles of mapped passages. Above ground, the farmland was allowed to recycle itself back to forest again, and slowly the wildlife such as deer and wild turkey returned to the area. As knowledge about the cave system grew, it was recognized as the largest cave in the world, three times larger than any other system. In 1981, Mammoth National Park was declared a World Heritage Site and, in 1990, it became an International Biosphere Reserve.

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The Cave Tours

There are 13 tours available through different parts of the caverns. They vary in cost depending on the sections of the cave to be viewed, the length of the tour (1/2 hour up to 6 ½ hours), and the comfort level of the passages.

Although photography and videotaping is allowed, the use of tripods, monopods, walking sticks, and canes (unless needed for health reasons) are forbidden because they create tripping hazards. Since most of the tours include stairways and bumpy passages, strollers are also forbidden. Some visitors choose to carry their toddlers in backpack style carriers which is fine, but it is necessary to be aware of the low ceiling and bending areas in order to avoid bumping the child's head.

Temperature in the cave stays between 127ºC and 18ºC, so visitors are encouraged to carry light jackets even in summertime. Also because the cave floors and stairs can be slick and wet, visitors should wear durable, flat-soled footwear that offers good traction.

What to Do Above Ground

Mammoth National Park has much to offer above ground as well as below. There are 60 miles of hiking trails through beautiful woodland hills made up of beech, black oak, white oak, poplar, and hickory. The trails, some of which can now be used for biking and are wheelchair accessible, are being improved and expanded every year with the help of local volunteers. Horses can be rented for the many horseback trails, and canoes are available for use on the 31 miles of Green River waterway. Fishing is encouraged but swimming is not allowed due to the depth of the river. If you love river cruises but don't want to paddle, consider taking the Green River Cruise boat ride offered several times a day.

Mammoth Cave Tour © National Park Service
There are 13 tours available through different parts of the caverns.


The park system offers both camping for the sportsman and hotels for the vacationer. The campgrounds (tent and RV use) are in excellent condition with new restroom buildings, fire pits, picnic tables and potable water. Backpack camping is allowed in some limited areas, but campers must first sign in with the rangers. For supplies, a small general store, as well as showers and a post office are all less than a one-mile walk from the campground and cave tours.

For those who don't wish to camp, the park also has apartment-like hotel rooms, rental cabins and a coffee shop for dinners located right next to the park headquarters. The rooms are clean and attractive with balconies that lead out to the lovely wooded creek. However these are very popular, so be sure to make reservations early.

When to Visit

The park is open year round, but May through September is the best time to visit this park because of the mild summer weather. By April, the snow is gone and temperatures are in a comfortable range of 13ºC at night and 24ºC during the day. The summer months get as hot as 27ºC, but nighttime temperatures drop off to a comfortable18ºC. The winter snows usually begin in November and, although the park is open, some roads may be closed.

What's Nearby?

Cave City is the largest of several small towns that dot the edge of the park. It has several hotels, restaurants, gas stations and grocery stores but its main business is entertainment. Along the route into the park, tourists can find rock shops, carnival type rides, family entertainment areas and a golf course. Several other privately own caves are also open. They are all connected to the Mammoth underground system but may not be as well maintained as the park caves.

Written by: Carla Lee Suson
Top Photo Credit: © Daniel Schwen - GNU Free Documentation License
Photo Description: Western Kentucky is known as the land of a thousand sinkholes, with Mammoth National Park being at the center.