Established 7/1/1941 Size 52,830.19 acres (213.8 km2) With 392 miles (631 km) of passageways mapped, Mammoth Cave is by far the world's longest cave system. Cave animals include eight bat species, Kentucky cave shrimp, Northern cavefish, and cave salamanders. Above ground, the park contains Green River (Kentucky), 70 miles of hiking trails, sinkholes, and springs.[46]
National Park
https://www.nps.gov/lavo/index.htm
Established 8/9/1916 Size 106,372.36 acres (430.5 km2) Lassen Peak, the largest plug dome volcano in the world, is joined by all three other types of volcanoes in this park: shield, cinder dome, and composite. Other than the volcano, which last erupted in 1915, the park has hydrothermal areas, including fumaroles, boiling pools, and steaming ground, heated by molten rock under the peak.[45]
https://www.nps.gov/seki/index.htmÂ
https://www.nps.gov/jotr/index.htm
Established 10/31/1994 Size 789,745.47 acres (3,196.0 km2) Covering parts of the Colorado and Mojave Deserts and the Little San Bernardino Mountains, this is the home of the Joshua tree. Across great elevation changes are sand dunes, dry lakes, rugged mountains, and granite monoliths.[39]
Established 3/3/1931 Size 571,790.11 acres (2,314.0 km2) The largest island in Lake Superior, this park is a site of isolation and wilderness. It has many shipwrecks, waterways, and hiking trails. The park also includes over 400 smaller islands in the waters up to 4.5 miles (7.2 km) from the island. There are only 20 mammal species and it is known for its wolf and moose relationship.[38]
Established 3/4/1921 Size 5,549.75 acres (22.5 km2) The only National Park in an urban area, this smallest National Park is based around the natural hot springs that have been managed for public use. Bathhouse Row preserves 47 of these with many beneficial minerals.[37]
Established 10/15/1966 Size 86,415.97 acres (349.7 km2) This park has Guadalupe Peak, the highest point in Texas, the scenic McKittrick Canyon full of Bigtooth Maples, part of the Chihuahuan Desert, and a fossilized reef from the Permian.[34]
Established 6/15/1934 Size 521,490.13 acres (2,110.4 km2) The Great Smoky Mountains, part of the Appalachian Mountains, have a wide range of elevations, making them home to over 400 vertebrate species, 100 tree species, and 5000 plant species. Hiking is the park's main attraction, with over 800 miles (1,300 km) of trails, including 70 miles (110 km) of the Appalachian Trail. Other activities are fishing, horseback riding, and visiting some of nearly 80 historic structures.[33]
Established 9/13/2004 Size 42,983.74 acres (173.9 km2) The tallest dunes in North America are up to 750 feet (230 m) tall and neighbor grasslands, shrublands and wetlands. They were formed by sand deposits of the Rio Grande on the San Luis Valley. The park also has alpine lakes, six 13,000-foot mountains, and ancient forests.[32]
Established 10/27/1986 Size 77,180.00 acres (312.3 km2) Based around Wheeler Peak, the Great Basin has 5,000-year-old bristlecone pines, glacial moraines, and the limestone Lehman Caves. It has some of the country's darkest night skies, and there are animal species including Townsend's big-eared bat, Pronghorn, and Bonneville cutthroat trout.[31]