United States Geography

Area

Climate

predominantly temperate, with tropical climates in Hawaii and Florida, arctic conditions in Alaska, semiarid regions in the Great Plains west of the Mississippi River, and arid surroundings in the southwestern Great Basin; in the northwest, low winter temperatures are occasionally moderated in January and February by warm chinook winds from the Rocky Mountains' eastern slopes

Terrain

expansive central plain, western mountains, and eastern hills and low mountains; Alaska features rugged mountains and wide river valleys; Hawaii displays a rugged, volcanic landscape

Land use

Location

North America, situated between Canada and Mexico, borders both the North Atlantic Ocean and the North Pacific Ocean

Coastline

19,924 km

Elevation

Irrigated land

234,782 sq km (2017)

Major aquifers

Northern Great Plains Aquifer, Cambrian-Ordovician Aquifer System, Californian Central Valley Aquifer System, Ogallala Aquifer (High Plains), Atlantic and Gulf Coastal Plains Aquifer

Map references

North America

Land boundaries

Maritime claims

Natural hazards

tsunamis; volcanic activity; seismic events around the Pacific Basin; hurricanes impacting the Atlantic and Gulf coasts; tornadoes in the Midwest and Southeast; mudslides in California; wildfires in the western regions; flooding; permafrost in northern Alaska poses significant challenges for development

volcanism: volcanic activity is present in the Hawaiian Islands, Western Alaska, the Pacific Northwest, and the Northern Mariana Islands; Mauna Loa (4,170 m) in Hawaii and Mount Rainier (4,392 m) in Washington have been designated as Decade Volcanoes by the International Association of Volcanology and Chemistry of the Earth's Interior, meriting attention due to their explosive histories and proximity to populated areas; Pavlof (2,519 m) is the most active volcano within Alaska's Aleutian Arc and poses a considerable risk to international air travel; St. Helens (2,549 m), renowned for its catastrophic eruption in 1980, remains active; other historically significant volcanoes are primarily located in the Aleutian arc and Hawaii, including (in Alaska) Aniakchak, Augustine, Chiginagak, Fourpeaked, Iliamna, Katmai, Kupreanof, Martin, Novarupta, Redoubt, Spurr, Wrangell, Trident, Ugashik-Peulik, Ukinrek Maars, Veniaminof, (in Hawaii) Haleakala, Kilauea, Loihi, (in the Northern Mariana Islands) Anatahan, (in the Pacific Northwest) Mount Baker, and Mount Hood; see note 2 under "Geography - note"

Geography - note

note 1: the world's third-largest nation by area (trailing only Russia and Canada) and by population (following China and India); Mt. McKinley is the highest point (6,190 m; 20,308 ft) in North America, while Death Valley is the lowest point (-86 m; -282 ft)

note 2: the western coastline of the United States and the southern coastline of Alaska are situated along the Ring of Fire, a belt bordering the Pacific Ocean that encompasses approximately 75% of the planet's volcanoes and up to 90% of the world's seismic activity

note 3: the Aleutian Islands form a chain of volcanic islands that separate the Bering Sea (to the north) from the main Pacific Ocean (to the south); they extend roughly 1,800 km (1,118 mi) westward from the Alaskan Peninsula; this archipelago includes 14 larger islands, 55 smaller islands, and numerous islets; there are 41 active volcanoes within the islands, contributing to a significant northern segment of the Ring of Fire

note 4: Mammoth Cave, located in west-central Kentucky, holds the title of the world's longest known cave system, featuring over 650 km (405 miles) of mapped passageways, nearly double the length of the second-longest cave system, the Sac Actun underwater cave in Mexico (refer to "Geography - note" under Mexico)

note 5: Kazumura Cave on the island of Hawaii is recognized as the longest and deepest lava-tube cave globally, with a surveyed length of 66 km (41 mi) and a depth of 1,102 m (3,614 ft)

note 6: Bracken Cave, situated near San Antonio, Texas, is the largest bat cave in the world, serving as the summer sanctuary for the largest colony of bats globally; approximately 20 million Mexican free-tailed bats inhabit the cave from March to October, creating the largest known concentration of mammals

Natural resources

coal, copper, lead, molybdenum, phosphates, rare earth elements, uranium, bauxite, gold, iron, mercury, nickel, potash, silver, tungsten, zinc, petroleum, natural gas, timber, arable land

Area - comparative

approximately half the area of Russia; roughly three-tenths the area of Africa; about half the area of South America (or slightly larger than Brazil); marginally larger than China; over twice the area of the European Union

Geographic coordinates

38 00 N, 97 00 W

Population distribution

significant urban populations are distributed across the eastern portion of the United States (notably in the Great Lakes region, northeast, east, and southeast) as well as the western states; regions with mountain ranges like the Rocky Mountains and Appalachians, arid areas in the southwest, the thick boreal forests in the far north, and the central prairie regions tend to have lower population densities; the population of Alaska is mainly located along its southern coastline, especially near Anchorage, while Hawaii's population is primarily found on the island of Oahu

Major lakes (area sq km)

Major watersheds (area sq km)

Major rivers (by length in km)

Missouri - 3,768 km; Mississippi - 3,544 km; Yukon river mouth (shared with Canada [s]) - 3,190 km; Saint Lawrence (shared with Canada) - 3,058 km; Rio Grande river source (mouth shared with Mexico) - 3,057 km; Colorado river source (shared with Mexico [m]) - 2,333 km; Arkansas - 2,348 km; Columbia river mouth (shared with Canada [s]) - 2,250 km; Red - 2,188 km; Ohio - 2,102 km; Snake - 1,670 km

note: [s] after country name indicates river source; [m] after country name indicates river mouth