About the Site
Mammoth Cave National Park  



Cave Entrance

Cave Trails

Cave Passages


Above Ground


Green River





Located in south central Kentucky, Mammoth Cave National Park contains one of the world's truly remarkable wonders--the longest cave system on the planet. In addition to the underground caverns, the park preserves some 80 square miles--more than 52,000 acres--of Kentucky countyside.

Of course, the main reason for the existence of the park is the elaborate and spectacular cave system with about 350 miles of underground passages. This has been, since 1972, believed to be the longest cave system in the world, by a wide margin. The system contains many miles of large rooms, narrow and sizeable passages, and many types of formations including flowstone, draperies, stalagmites, stalactites, and other kinds of cave decorations.

Many cave areas are only accessible to professionals, but some 10 miles of the cave system is covered on the several tours which are provided by the National Park Service. These includes fairly simple hikes underground but also include more adventurous, "wild" cave tours.

The park also features beautiful woodlands, some of which are remnants of the great old growth forest which once covered much of Kentucky. Below is an example of this forest in the area of the Mammoth Cave Sink.


Formation of the Caves The many caves in this part of Kentucky are still growing, but they have been doing so for 350 million years. At this time the land presently within the confines of the park lay at the bottom of a shallow sea. The shells of decaying organisms, the calcium carbonate in the sea water, and pressure from the building and laying down of sedimentary layers resulted in the creation of a 500 foot layer of limestone. Additionally, several hundred feet of sandstone were deposited by river systems in the same area

For potential visitors, ParkVision recommends "Story Behind the Scenery" guides and "Trails Ilustrated" maps.

When the sea receded, the sandstone and limestone beneath it were exposed. The sandstone and shale "cap" resists the water and protects the limestone beneath it. Buckling and warping of the rock layers created cracks, which allow rainwater to seep into the rock from sinkholes on the surface of the land. Some 10,000 of these sinkholes exists in the area. The acidic rain water, flowing down and through the cracks, causes dissolution of the limestone, creating the caves themselves. The sandstone cap on the surface, above the limestone, presented dissolution of all of the limestone, creating the possibility for creation and preservation of the caverns.

These processes, in place for hundreds of millions of years, continue today, and so the caves continue to form and grow.

Human History Evidence exists that prehistoric humans explored the caves as long ago as 4000 years, primarily for the purpose of gathering cave minerals such as gypsum and flint. However, this prehistoric activity seemed to have ceased about 2000 years ago.

The first modern owner of the caves was Valentine Simons who purchased the property in 1798. The property was purchased in 1810 by Charles Wilkins, who put the caves to use for the mining of saltpeter, an ingredient for the production of gunpowder, by slaves for use in the War of 1812. This activity was fairly short-lived, but the caverns emerged as a major tourist attraction after 1816. The caves are sometimes regarded as the United States' second-oldest tourist attraction, behind only Niagara Falls in New York. A variety of famous historical figures visited the caves, including Jenny Lind, Edwin Booth, Charles Dickens, William Jennings Bryan, and Ralph Waldo Emerson.

Organized tourist activity accelerated after the purchase of the caves by Franklin Gorin in 1828. Under his ownership organized tours were conducted, including those by famous slave-turned-guide Stephen Bishop. Bishop explored and discovered many parts of the cave, and is credited with the discovery of the underground river system, including the River Styx, which is an essential part of the cave, as well as Mammoth Dome and many other parts of the cave. Gorin also built a hotel to accommodate visitors. Interest in the attraction was great enough that, between 1886 and 1929, the caves were served by the Mammoth Caves Railroad.

For many years cave explorers had hoped to link the Mammoth Cave System with the nearby system underneath Flint Ridge. This was finally accomplished in 1972. Once these caves were linked the system became the longest cave system in the world. It is presently been mapped to a length of 350 to 400 miles of underground passages. Mammoth Cave is also believed to be the most stable cave system known to man.

Establishment of the National Park The idea of creating a national park to conserve the magnificent caves arose as early as 1905. This idea gained considerable support in 1924 with the founding of the Mammoth Cave National Park Association. Through the efforts of this group and others, the park was authorized by an act of Congress signed by Calvin Coolidge 1926, contingent on acquisition of necessary park property. The park was not officially established until 1941, but the dedication was postponed because of World War II until September of 1946. The caves were late designated a UNESCO World Heritage Site.

After creation of the park additional properties and features were later incorporated. This including the addition of Great Onyx and Crystal Caves, which once competed with Mammoth Cave as attractions. Also noteworthy was the contribution of the CCC, which in 1940 provided 600 boys working on various projects in the park and whose work continued for 9 years.

Cave Entrance

The main section of Mammoth Cave is believed to have been discovered in 1797 by Robert Houchins. He is said to have been pursuing a wounded bear he was hunting which disappeared into the main entrance to the cave. This entrance is known as the Historical Entrance and is shown below

There are presently some 30 entrances to the caves, approximately a quarter of which are natural. However, the Historical Entrance was the only one known until 1921. It is currently the only natural entrance which is used on the public cave tours offered by the National Park Service. A group of tourists waiting for one of these tours is shown below outside the entrance. The Historical Entrance is located very close to the main tourist area in the park where the hotel, gift shop, and other amenities for visitors are located.

A paved walkway and a stairway with handrails now provides safe access to the caves for visitors via the Historical Entrance. The view below looks back out from the entrance itself.

- Next Page for Mammoth Cave National Park -

  • All photographs ©Patrick Holleran, Shannon Digital Imaging, 1994-2013

  • Commercial use of the images contained in this document without express written consent is strictly prohibited.

  • Comments and other remarks can be sent via e-mail to parkvision@shannontech.com