section_path: Geography
section_name: Geography
paragraph_text: Geography
  
  The United States is the world's third-largest country by total area behind Russia and Canada. The 48 contiguous states and the District of Columbia have a combined area of 3,119,885 square miles (8,080,470 km 2). In 2021, the United States had 8% of the earth's permanent meadows and pastures and 10% of its cropland.
  
  Starting in the east, the coastal plain of the Atlantic seaboard gives way to inland forests and rolling hills in the Piedmont plateau region. The Appalachian Mountains and the Adirondack Massif separate the East Coast from the Great Lakes and the grasslands of the Midwest. The Mississippi River System, the world's fourth-longest river system, runs predominantly north–south through the center of the country. The flat and fertile prairie of the Great Plains stretches to the west, interrupted by a highland region in the southeast.
  
  The Rocky Mountains, west of the Great Plains, extend north to south across the country, peaking at over 14,000 feet (4,300 m) in Colorado. The supervolcano underlying Yellowstone National Park in the Rocky Mountains, the Yellowstone Caldera, is the continent's largest volcanic feature. Farther west are the rocky Great Basin and the Chihuahuan, Sonoran, and Mojave deserts. In the northwest corner of Arizona, carved by the Colorado River, is the Grand Canyon, a steep-sided canyon and popular tourist destination known for its overwhelming visual size and intricate, colorful landscape. The Cascade and Sierra Nevada mountain ranges run close to the Pacific coast. The lowest and highest points in the contiguous United States are in the State of California, about 84 miles (135 km) apart.
  
  At an elevation of 20,310 feet (6,190.5 m), Alaska's Denali is the highest peak in the country and continent. Active volcanoes are common throughout Alaska's Alexander and Aleutian Islands. Located entirely outside North America, the archipelago of Hawaii consists of volcanic islands, physiographically and ethnologically part of the Polynesian subregion of Oceania.