Established 5/30/1934 Size 1,508,537.90 acres (6,104.8 km2) The Everglades are the largest subtropical wilderness in the United States. This mangrove ecosystem and marine estuary is home to 36 protected species, including the Florida panther, American crocodile, and West Indian manatee. Some areas have been drained and developed; restoration projects aim to restore the ecology.[25]

https://www.nps.gov/deva/index.htm

Established 10/31/1994 Size 3,372,401.96 acres (13,647.6 km2) Death Valley is the hottest, lowest, and driest place in the United States. Daytime temperatures have topped 130°F (54°C) and it is home to Badwater Basin, the lowest point in North America. There are canyons, colorful badlands, sand dunes, mountains, and over 1000 species of plants in this graben on a fault line. Further geologic points of interest are salt flats, springs, and buttes.[22]

Established 10/11/2000 Size 32,860.73 acres (133.0 km2) This park along the Cuyahoga River has waterfalls, hills, trails, and displays about early rural living. The Ohio and Erie Canal Towpath Trail follows the Ohio and Erie Canal, where mules towed canal boats. The park has numerous historic homes, bridges, and structures.[20] The park also offers a scenic train ride with various trips available. [21]

Established 5/22/1902 Size 183,224.05 acres (741.5 km2) Crater Lake lies in the caldera of Mount Mazama formed 7,700 years ago after an eruption. It is the deepest lake in the United States and is known for its blue color and water clarity. There are two islands in the lake, and, with no inlets or outlets, all water comes through precipitation.[19]

Established 11/10/2003 Size 26,545.86 acres (107.4 km2) On the Congaree River, this park is the largest portion of old-growth floodplain forest left in North America. Some of the trees are the tallest in the Eastern US, and the Boardwalk Loop is an elevated walkway through the swamp.[18]

https://www.nps.gov/chis/index.htm

Established 3/5/1980 Size 249,561.00 acres (1,009.9 km2) Five of the eight Channel Islands are protected, and half of the park's area is underwater. The islands have a unique Mediterranean ecosystem. They are home to over 2,000 species of land plants and animals, and 145 are unique to them. The islands were originally settled by the Chumash people.[17]

https://www.nps.gov/cave/

Established 5/14/1930 Size 46,766.45 acres (189.3 km2) Carlsbad Caverns has 117 caves, the longest of which is over 120 miles (190 km) long. The Big Room is almost 4,000 feet (1,200 m) long, and the caves are home to over 400,000 Mexican Free-tailed Bats and sixteen other species. Above ground are the Chihuahuan Desert and Rattlesnake Springs.[16]

Established 12/18/1971 Size 241,904.26 acres (979.0 km2) The park's Waterpocket Fold is a 100-mile (160 km) monocline that shows the Earth's geologic layers. Other natural features are monoliths and sandstone domes and cliffs shaped like the United States Capitol.[15]

Established 9/12/1964 Size 337,597.83 acres (1,366.2 km2) This landscape was eroded into canyons, buttes, and mesas by the Colorado River, Green River, and their tributaries, which divide the park into three districts. There are rock pinnacles and other naturally sculpted rock, as well as artifacts from Ancient Pueblo Peoples.[14]