Mammoth Cave National Park is a U.S. National Park in central Kentucky, encompassing portions of Mammoth Cave, the longest cave system known in the world. Mammoth Cave developed in thick Mississippian-aged limestone strata capped by a layer of sandstone, making the system remarkably stable. It is known to include more than 367 miles (591 kilometers) of passageway; new discoveries and connections add several miles to this figure each year.


Several sets of Native American remains have been recovered from Mammoth Cave, or other nearby caves in the region, in both the 19th and 20th centuries, by 1813 on the early side (the "Short Cave Mummy.") Most mummies found present examples of intentional burial, with ample evidence of pre-Columbian funerary practice. An exception to purposeful burial was discovered when in 1935 the remains of an adult male were discovered by Grover Campbell and Lyman Cutliff under a large boulder. The boulder had shifted and settled onto the victim, a pre-Columbian miner, who had disturbed the rubble supporting it. The remains of the ancient victim were named "Lost John" and exhibited to the public into the 1970s, when they were interred in a secret location in Mammoth Cave for reasons of preservation as well as emerging political sensitivities with respect to the public display of Native American remains.


On September 9, 1972, a Cave Research Foundation mapping team managed to pursue a low, wet passage that linked two of the area's long cave systems—Flint Ridge Cave System to Mammoth Cave. This connection made the combined Flint–Mammoth Cave System the world's longest. In recent years, more connections between Mammoth Cave and smaller caves or cave systems have followed, notably to Proctor/Morrison Cave beneath nearby Joppa Ridge in 1979. This connection pushed the frontier of Mammoth exploration southeastward. At the same time, discoveries made outside the Park by an independent group called the Central Kentucky Karst Coalition or CKKC resulted in the survey of tens of miles in Roppel Cave east of the Park. On September 10, 1983, a connection was made between the Proctor/Morrison's section of the Mammoth Cave system and Roppel Cave. It is a certainty that many more miles of cave passages await discovery in the region. Scientists believe that there are thousands of species of animals yet undiscovered in the cave system.


Much research has been conducted on the ecosystems of Mammoth Cave. The bats that inhabit the caverns are the following: Indiana bats (Myotis sodalis), Gray bats (Myotis grisescens), Little brown bats (Myotis lucifugus), Big brown bat (Eptisecus fuscus), and the Eastern pipistrelle bat (Pipistrellus subflavus)



Common misconceptions rise concerning Mammoth Cave's impressive length—given the documented mileage of the passageways. The data are justly applied to Mammoth Cave often lead to exaggeration of the cave's extent and reach. One such misconception is that the cave extends far beyond its well-known geographical boundaries, even to other states in the United States. This misconception is easily debunked. Caves of Mammoth's type form as water from the surface seeks the level of the surface streams which drain them: in Mammoth Cave's case, the Green River to the north. It is a virtual certainty that no cave passages connecting to Mammoth will ever be found north of the Green River, or substantially east of the Sinkhole Plain, which is the primary recharge area (the place where water enters) for the cave. More tantalizing is the prospect of ancient passages to the south which might bridge the current drainage divide between the Green River basin and the Barren River basin south of it, but in that case, the maximum expected southerly extent of Mammoth Cave would be the Barren River. It is true, however, that the layers of sedimentary rock in which Mammoth Cave has formed do extend many miles in almost any direction from Mammoth Cave. These rocks were all laid down over the same period. The similarity of the rocks of the broader region to those in the immediate vicinity of Mammoth Cave means that conditions are right for cave formation; however, the absolute boundaries of the Mammoth Cave system are known, so it is expected that these other caves will not be found to connect to Mammoth Cave.


Another commonly held misconception is related to the Mammoth Cave System's name. No fossils of the Wooly Mammoth have ever been found in Mammoth Cave, and the name of the cave has nothing to do with this extinct mammal. Rather, the appellation "Mammoth" refers to the staggering length of its horizontal extent to that of other caves.


It is accepted by most informed researchers that many more miles of the Mammoth Cave system await discovery. The extra mileage to be discovered will likely occur both in the form of new passages that await discovery (as more sophisticated techniques of cave exploration develop) and of neighboring cave systems whose extensive mileage could, at any moment, be found to be part of Mammoth Cave through the discovery of passages linking these heretofore-considered independent caves.