Mammoth Cave National Park

Mammoth Cave National Park

Preserving the Park

Despite the incredible amount of work performed by dedicated scientists, park administrators and citizens since the park's establishment in 1941, Mammoth Cave's unique biologic and geologic assets continue to face threats from a variety of sources. Air and groundwater pollution, invasive species and nearby industrial development are just a few of the many factors that threaten this fragile ecosystem.


Degraded scenic vistas: The estimated annual average natural visibility at Mammoth Cave is 113 miles. Air pollution, however, reduces average visual range to approximately 14 miles from June through August, making Mammoth Cave one of America's haziest national parks. In fact, Mammoth Cave, as well as Shenandoah and Great Smoky Mountain national parks, are among the most polluted national parks in the country of those that monitor air quality.

Ozone exposure: Mammoth Cave ranks as the fifth-most ozone-polluted park in America. Scientists are beginning to investigate whether ozone exposure in the park reduces growth in black cherry and sycamore trees, both ozone-sensitive species that provide key nesting grounds for the endangered Indiana Bat.

Mercury deposition: The National Park Service and other agencies began in 2001 to monitor mercury levels at Mammoth Cave. Scientists are particularly concerned about mercury's impacts on the park's seven endangered freshwater mussel species. Mammoth Cave has also been affected by a statewide fish consumption advisory due to mercury contamination.

Fine particle pollution: Recent studies increasingly show that pollution in the form of small particles, called fine particulate matter, poses significant risks to human health. Mammoth Cave National Park has some of the highest levels of particulate pollution of any national park.

Industrial Development: Environmentalists are concerned that power plants worsen existing air pollution. With the current state of air quality, Mammoth Cave has little room for further environmental degradation.

Pollution Solution

Although there is no such thing as an easy solution to pollution, Mammoth Cave National Park is making its best efforts to improve the quality of the air overhead. The park was the first Department of the Interior site in the country to have a dedicated E-85 ethanol fueling station. The fueling station was purchased through a grant in partnership with the Kentucky Corn Growers Association. The park has 16 bi-fuel vehicles that use over 3,000 gallons of E-85 ethanol. Mammoth Cave is the first Southeast Region park to use biodiesel fuel, converting all 25 pieces of its diesel equipment to B-20 biodiesel blend in 2001. 

Mammoth Cave joined with concessioner Forever Resorts in an agreement whereby park staff collects and recycles all aluminum cans. Forever Resorts also takes responsibility for recycling all cardboard waste. The amount of waste hauled to landfills and the cost of getting it there has been greatly reduced. Mammoth Cave National Park has also significantly increased the use of recycled lumber for park projects.


In 2002, after an almost 200-year absence, fire once again has reassumed its role in the natural order of the park's communities with the inauguration of the Mammoth Cave National Park Fire Management Plan. "Prescribed" fires are set in the park under strictly controlled circumstances to begin the process of reversing the many years of total fire suppression. It is important that the public understand the ecological role fire plays in the park. In prairies, savannas or forests, vegetation depends on fire for key biological processes. In the absence of fire, the ramifications spread far beyond fire-dependent plants. In the riparian and connected aquatic cave ecosystem, vegetation determines the amounts and quality of water, sediment and organic matter that enter. In the terrestrial cave ecosystem, the presence of insects, fungi and plants available to bats, wood rats and cave crickets are largely determined by major vegetation types. As strange as it may seem, the preservation of the wonderful scenery at Mammoth Cave is enhanced through burning. The undergrowth and forest flora burn, reducing hazardous fuel and releasing nutrients into the soil, continuing the vital life cycles in the park.

Exotic Species

There are two categories of exotic species which have had significant impact on park forests: pathogens and invasive plants. Chestnut Blight and Dutch Elm Disease have virtually eliminated American Chestnut and American Elm and a similar fungal disease is currently affecting the American Butternut tree. Invasive exotic plant species such as honeysuckle, garlic mustard, kudzu, Microstegium, silver poplar and Ailanthus overcome native species and spread with little competition. With over 1,000 species of flowering plants including 84 tree species—the potential for loss of biodiversity in Mammoth Cave National Park is great.


Since large portions of the upper Green River watershed and the groundwater basins affecting Mammoth Cave National Park lay outside park boundaries, the use of these areas greatly influence water quality within the park. The primary activities that affect the park's water quality include: disposal of domestic, municipal and industrial sewage, solid waste disposal, agricultural and forestry management practices, oil and gas exploration and production, urban land-use and recreational activities. As a result, groundwater has been intensively studied for years. Groundwater dye tracing, which serves to define groundwater basins, has been completed. Baseline water quality inventories have been performed, as well as investigations into the mechanisms of non-point contaminant transport and water quality. The park also operates several continuous-recording digital water monitoring sites, which yield data relative to physical and gross chemical characteristics. 

Endangered Species

Mammoth Cave National Park is home to over 70 threatened, endangered or listed species. These species include birds, crustaceans, fish, gastropods, insects, mammals, mussels, plants and reptiles. The Federal Endangered Species Act of 1973 recognizes that many of our species across the United States have been lost and others are close to extinction. This act enables agencies to take the necessary measures to protect and restore these species and prevent them from being permanently wiped out. Through education and restoration programs, the park hopes to prevent further destruction caused by human impact.

World Heritage Site

On October 27, 1981, Mammoth Cave National Park joined the ranks of renowned places like Australia's Great Barrier Reef, Egypt's Pyramids of Giza, Nepal's Kathmandu Valley and India's Taj Mahal Historic Park. The United Nations Educational, Scientific and Cultural Organization (UNESCO) designated Mammoth Cave National Park as a World Heritage Site for its exceptional natural features and habitat for threatened and endangered species. 

Biosphere Reserve

On September 26, 1990, Mammoth Cave was officially designated an Area Biosphere Reserve by UNESCO. A biosphere reserve is a unique category of safeguarded, natural environments combining conservation and sustained economic use of natural resources. Each biosphere reserve represents a specific ecosystem; a place for research, monitoring and education, and a place where government policy makers, scientists and local people cooperate to manage land and water resources to meet human needs while conserving natural resources. Biosphere reserve designations are made by UNESCO following recommendation by a scientific panel, concurrence of the site administrator, and nomination by the U.S. National Committee for Man and the Biosphere Program.

What You Can Do

Pack out what you pack in. Trash is not only an eyesore, but is also a risk to animals. Dispose of waste properly and use recyclable camp supplies. There's a real satisfaction in knowing that you left an area in better shape than you found it.

Don't touch the cave formations. Oils from your hand can cause deformities in the speleothems. 

Don't feed the animals. By simply not feeding the animals, you will protect their welfare. When wild animals cease to find their own food, they cease to be part of the balance of nature.

Stay on established trails. By taking short cuts you may get lost, and you may damage vegetation and animal life.

Camping. You can help protect Mammoth Cave by practicing minimum-impact camping. Obey park regulations and camp only in designated camping areas. Safeguard your belongings by hanging your pack, food and sweet-smelling items (soap, toothpaste and shampoo), away from hungry or curious rodents. 

Get involved. On a larger scale, programs such as "Take Pride In America" involve groups that get together to rehabilitate ecosystems, improve hiking trails where erosion and overuse are taking a toll, or identify and remove exotic plants that might encroach on native species. Mammoth Cave welcomes both individuals and groups to participate in its Volunteers in Parks (VIPs) Program.