With over 350 miles of passageways, Mammoth Cave is the longest known cave system in the world. No other cave even comes close. And explorers aren't even done mapping it yet! The cave system features five separate levels of subterranean rooms, narrow passageways, deep shafts, and underground rivers, all some 400-feet underground. While many visitors come to explore the depths of the cave, Mammoth Cave National Park also protects more than 52,000 acres of land, including rolling hills, sinkholes, and the Green River Valley. Outside the cave, visitors enjoy views from ridge tops covered with oak and hickory forests, deep valleys, and scenic bluffs. The park is home to a variety of animals including eastern white-tailed deer, bobcats and great blue herons. With more than 200 different bird species, birders may well be able to add a few dozen new species to their life list.

The natural wonders of the park are quite diverse, but they can be overshadowed by polluted air. According to NPCA's research, Mammoth Cave National Park is one of the five most polluted parks in the park system. The haziest days in Mammoth Cave are worse than those in any other national park or wilderness area and often match that of urban areas. The park is downwind of large, coal-fired power plants that produce much of the sulfur pollution responsible for hazy skies. NPCA is fighting on both the national and local levels to clear the air in our parks to ensure the long-term health of the parks and their visitors.

If You Go

Mammoth Cave National Park is located in central Kentucky, about 35 miles northeast of Bowling Green, Kentucky, and about 90 miles southwest of Louisville. Make reservations for the cave tours before you go, especially between the months of April and October. Tours of the caves are popular and fill up quickly.

Threats

Air pollution is among the most serious threats to national parks. The National Park Service has established the NPS air quality webcam network to show “live” digital images of more than a dozen parks. Click here to see current air conditions at Mammoth Cave National Park.