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{{Short description|none}}
{{redirect|Geography of America|geography of the continental landmass|Geography of North America|and|Geography of South America}}
{{use mdy dates|date=November 2020}}
[[File:Map_of_USA_with_state_and_territory_names_2.png|thumb|A political map of the [[United States]] showing the 50 [[U.S. state|states]], the national capital of [[Washington, D.C.]], and the five major [[Territories of the United States|U.S. territories]].{{refn|group=note|Areas not on the map: [[Aleutian Islands]] ([[Alaska]]); [[Northwest Hawaiian Islands]] ([[Hawaii]]); [[Mona Island]] ([[Puerto Rico]]); [[Rota (island)|Rota]] and [[Northern Islands Municipality]] ([[Northern Mariana Islands]]); [[Manu'a|Manu'a Islands]], [[Rose Atoll]] and [[Swains Island]] ([[American Samoa]]) and the [[U.S. Minor Outlying Islands]]}}|alt=Political map of the United States.]]
{{Country geography
| name = the United States
| map = USA topo en.jpg
| map size = 250
| continent = [[North America]] (except Hawaii and territories)
| region =
| coordinates = {{Coord|40|N|100|W}}
| area ranking = 3rd/4th
| km area = 9,826,675
| percent land = 93.24
| percent water = 6.76
| km coastline = 19920
| borders = [[Canada]]: {{convert|8864|km|mi|0|abbr=on}}<br />[[Mexico]]: {{convert|3327|km|mi|0|abbr=on}}
| highest point = [[Denali|Denali/Mount McKinley]]<br />{{convert|6190.5|m|ft|0|abbr=on}}
| lowest point = [[Badwater Basin]],<br />{{convert|-85|m|ft|0|abbr=on}}
| longest river = [[Missouri River]],<br />{{convert|3767|km|mi|0|abbr=on}}
| largest lake = (shared) [[Lake Superior]]<br />{{convert|58000|km2|sqmi|0|abbr=on}}<br>(internal) [[Iliamna Lake]]<br>{{convert|2600|km2|sqmi|0|abbr=on}}
| climate = Diverse: Ranges from warm-summer continental in the far north to tropical in the far south. West: mostly semi-arid to desert, Mountains: alpine, Northeast: humid continental, Southeast: humid subtropical, Coast of California: Mediterranean, Pacific Northwest: cool temperate oceanic, Alaska: mostly subarctic, Hawaii, South Florida, and the territories: tropical
| terrain = Vast central plain, Interior Highlands and low mountains in Midwest, mountains and valleys in the mid-south, coastal flatland near the Gulf and Atlantic coasts, complete with mangrove forests and temperate, subtropical, and tropical laurel forest and jungle, canyons, basins, plateaus, and mountains in west, hills and low mountains in east; intermittent hilly and mountainous regions in Great Plains, with occasional badland topography; rugged mountains and broad river valleys in Alaska; rugged, volcanic topography in Hawaii and the territories
| 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
| natural hazards = Tsunamis; volcanoes; earthquake activity around Pacific Basin; hurricanes along the Atlantic and Gulf of Mexico coasts; severe convective thunderstorms and tornadoes in the Midwest, Great Plains and Southeast; mud slides in California; forest and brush fires in the west and central regions, especially; flooding; dust storms in western and central regions; permafrost in northern Alaska
| environmental issues = Environmental issues
Deforestation, energy irresponsibility, pollution, nuclear waste, Severe water shortages, air pollution resulting in acid rain in both the US and Canada
| exclusive economic zone = {{convert|11,351,000|km2|mi2|abbr=on}}
}}
<span lang="en-us" dir="ltr">The</span> term "[[United States]]," when used in the geographic sense, refers to the [[contiguous United States]] (sometimes referred to as the [https://www.britannica.com/dictionary/Lower-48 Lower 48], including the [[Washington, D.C.|District of Columbia]] not as a state), [[Alaska]], [[Hawaii]], the five [[Insular area|insular]] [[Territories of the United States|territories]] of [[Puerto Rico]], [[Northern Mariana Islands]], [[United States Virgin Islands|U.S. Virgin Islands]], [[Guam]], [[American Samoa]], and [[United States Minor Outlying Islands|minor outlying possessions]].<ref name=":0">U.S. State Department, [https://2009-2017.state.gov/j/drl/rls/179780.htm Common Core Document to U.N. Committee on Human Rights], December 30, 2011, Item 22, 27, 80; Homeland Security [https://www.dhs.gov/xlibrary/assets/hr_5005_enr.pdf Public Law 107-296] Sec.2.(16)(A); Presidential Proclamation of national jurisdiction [http://www.gpo.gov/fdsys/pkg/CFR-2000-title3-vol1/pdf/CFR-2000-title3-vol1-proc7219.pdf]</ref> The United States shares land borders with [[Canada]] and [[Mexico]] and [[Maritime boundary|maritime borders]] with [[Russia]], [[Cuba]], [[the Bahamas]], and many other countries, mainly in the Caribbean{{refn|group=note|The United States has a maritime border with the [[United Kingdom]] because the [[U.S. Virgin Islands]] borders the [[British Virgin Islands]].<ref>https://www.britannica.com/place/United-States-Virgin-Islands. Britannica.com. United States Virgin Islands. Retrieved July 3, 2020. {{Webarchive|url=https://web.archive.org/web/20200429112829/https://www.britannica.com/place/United-States-Virgin-Islands |date=April 29, 2020 }}</ref> [[Puerto Rico]] has a maritime border with the [[Dominican Republic]].<ref>https://www.britannica.com/place/Puerto-RicoBritannica.com. Puerto Rico. Retrieved July 3, 2020. {{Webarchive|url=https://web.archive.org/web/20200702120024/https://www.britannica.com/place/Puerto-Rico |date=July 2, 2020 }}</ref> [[American Samoa]] has a maritime border with the [[Cook Islands]] (see [[Cook Islands–United States Maritime Boundary Treaty]]).<ref>Anderson, Ewan W. (2003). International Boundaries: A Geopolitical Atlas. Routledge: New York. {{ISBN|9781579583750}}; OCLC 54061586</ref><ref>Charney, Jonathan I., David A. Colson, Robert W. Smith. (2005). International Maritime Boundaries, 5 vols. Hotei Publishing: Leiden.</ref> American Samoa also has maritime borders with [[Samoa|independent Samoa]] and [[Niue]].<ref>http://www.pacgeo.org/static/maritimeboundaries/Pacgeo.org. Maritime Boundaries. Retrieved July 3, 2020. {{Webarchive|url=https://web.archive.org/web/20200731224602/http://www.pacgeo.org/static/maritimeboundaries/ |date=July 31, 2020 }}</ref>}}in addition to [[Canada]] and [[Mexico]]. The [[Canada–United States border|northern border of the United States with Canada]] is the world's longest bi-national land border.
The state of [[Hawaii]] is [[Physical geography|physiographically]] and [[Ethnology|ethnologically]] part of the [[Polynesia]]n subregion of [[Oceania]].<ref>{{cite web |title=Is Hawaii a Part of Oceania or North America? |url=https://www.worldatlas.com/articles/is-hawaii-a-part-of-oceania-or-north-america.html |url-status=live |website=WorldAtlas |date=January 12, 2018 |access-date=June 24, 2019 |archive-url=https://web.archive.org/web/20190711143815/https://www.worldatlas.com/articles/is-hawaii-a-part-of-oceania-or-north-america.html |archive-date=July 11, 2019}}</ref> U.S. territories are located in the [[Pacific Ocean]] and the [[Caribbean]].
==Area==
From 1989 through 1996, the total area of the US was listed as {{convert|9372610|km2|sqmi|abbr=on}} (land and inland water only). The listed total area changed to {{convert|9629091|km2|sqmi|abbr=on}} in 1997 (Great Lakes area and coastal waters added), to {{convert|9631418|km2|sqmi|abbr=on}} in 2004, to {{convert|9631420|km2|sqmi|abbr=on}} in 2006, and to {{convert|9826630|km2|sqmi|abbr=on}} in 2007 (territorial waters added). Currently, the CIA ''[[The World Factbook|World Factbook]]'' gives {{convert|9826675|km2|sqmi|abbr=on}},<ref name="WF">{{cite web|url=https://www.cia.gov/the-world-factbook/countries/united-states/|title=United States|publisher=CIA|work=The World Factbook|date=2009-09-30|access-date=2010-01-05}}</ref> the [[United Nations Statistics Division]] gives {{convert|9629091|km2|sqmi|abbr=on}},<ref>{{cite web|url=http://unstats.un.org/unsd/demographic/products/dyb/DYB2005/Table03.pdf|title=Population by Sex, Rate of Population Increase, Surface Area and Density|publisher=UN Statistics Division|work=Demographic Yearbook 2005|access-date=2008-03-25}}</ref> and the ''Encyclopedia Britannica'' gives {{convert|9522055|km2|sqmi|abbr=on}} (Great Lakes area included but not coastal waters).<ref>{{cite encyclopedia|url=https://www.britannica.com/EBchecked/topic/616563/United-States|title=United States|encyclopedia=Encyclopædia Britannica|access-date=2008-03-25}}</ref> These sources consider only the 50 states and the Federal District and exclude overseas territories. The US has the 2nd largest [[Exclusive Economic Zone]] of {{convert|11,351,000|km2|mi2|abbr=on}}.
<!--When editing this section, please note the distinction drawn between TOTAL AREA (i.e., including water) and TOTAL LAND AREA (excluding water), as the rankings change.-->By [[List of countries and outlying territories by total area|total area]] ([[Territorial waters|water]] as well as land), the United States is either slightly larger or smaller than the [[People's Republic of China]], making it the world's third or fourth-largest country.<ref>{{Cite web |title=Largest Countries in the World by Area |url=https://www.worldometers.info/geography/largest-countries-in-the-world/ |access-date=2025-03-28 |website=Worldometer |language=en}}</ref> Both countries are smaller than [[Russia]] and [[Canada]] in total area but are larger than [[Brazil]]. By land area only (exclusive of waters), the United States is the world's third largest country, after Russia and China, with Canada in fourth. Whether the US or China is the third largest country by total area depends on two factors: (1) the validity of China's claim on [[Aksai Chin]] and [[Trans-Karakoram Tract]] (both these territories are also claimed by India, so are not counted); and (2) how the US calculates its surface area. Since the initial publishing of the World Factbook, the CIA has updated the total area of the United States several times.<ref>{{Citation|url=http://www.theodora.com/wfb/abc_world_fact_book.html|title=Countries of the World: 21 Years of World Facts|publisher=geographic.org|access-date=2008-08-17}}</ref>
==General characteristics==
{{See also|Borders of the United States}}
[[File:USA-satellite.jpg|thumb|A satellite image of the [[contiguous United States]], where temperate and [[subtropical]] forests of deciduous, coniferous, broadleaved evergreen, mixed vegetation, [[grassland]]s, montane forests, and croplands prevail are prevalent in the [[East Coast of the United States|east]], transitioning to [[prairie]]s, [[boreal forest]]s, the [[Rocky Mountains|Rockies]] in the [[Western United States|west]], and [[desert]]s in the [[Southwest United States|southwest]]. Much of the country's population is centered around the [[Great Lakes]] and [[East Coast of the United States|Atlantic states]].]]
[[File:HawaiiGeography.png|thumb|A satellite image of [[Hawaii]], where [[volcanoes]] prevail on the [[Hawaii (island)|Big Island]]; the islands have rugged coastlines, sandy beaches, and a tropical environment, though temperatures and humidity tend to be less extreme because of nearly constant trade winds from the east.]]
The United States shares land borders with
Forty-eight of the states are in the single region between Canada and Mexico
The nation's capital city, [[Washington, D.C.]], was established in 1800 after being relocated there from [[Philadelphia]]. It was established as a federal district located on land donated by the state of [[Maryland]]; [[Virginia]] also donated land, but it was returned in 1849. The United States also has [[Territories of the United States|overseas territories]] with varying levels of autonomy and organization, including the [[Caribbean]] territories of [[Puerto Rico]] and the [[U.S. Virgin Islands]], formerly known as the Danish Virgin Islands and purchased by the United States at the beginning of [[World War II]], the Pacific territories of [[American Samoa]], [[Guam]] and the [[Northern Mariana Islands]], and several [[U.S. Minor Outlying Islands|uninhabited island territories]]. Some of the territories acquired were part of the [[territorial evolution of the United States]] or a product of the nation's effort to gain access to the east.
Nearly all of the United States is in the [[Northern Hemisphere]] with the exception of [[American Samoa]] and [[Jarvis Island]].<ref>https://www.cia.gov/library/publications/the-world-factbook/graphics/ref_maps/physical/pdf/standard_time_zones_of_the_world.pdf{{Webarchive|url=https://web.archive.org/web/20180108181645/https://www.cia.gov/library/publications/the-world-factbook/graphics/ref_maps/physical/pdf/standard_time_zones_of_the_world.pdf |date=January 8, 2018 }} CIA World Factbook – Standard Time Zones of the World, May 2018. (Map of the world showing the ___location of the contiguous U.S., Alaska, Hawaii, and the U.S. territories. Territories south of the "0" horizontal line (the equator) are in the southern hemisphere). Retrieved September 1, 2019.</ref>
==Physiographic divisions==
[[File:US physiographic map.jpg|thumb|A [[physiography|physiographical]] map of the contiguous 48 states of the U.S. and indicating the age of the exposed surface and the type of terrain]]
[[File:Scipio Township near Republic.jpg|thumb|An aerial photo over northern [[Ohio]]; much of the central United States is covered by relatively flat, arable land.]]
Within the continental U.S. there are [[Physiographic regions of the United States|eight distinct physiographic divisions]].<ref>{{cite web|title=Physiographic Regions |publisher=[[United States Geological Survey]] |date=2003-04-17 |url=http://tapestry.usgs.gov/physiogr/physio.html |access-date=2008-01-30 |url-status=dead |archive-url=https://web.archive.org/web/20060515044037/http://tapestry.usgs.gov/physiogr/physio.html |archive-date=2006-05-15 }}</ref> These major divisions are:
* [[Laurentian Upland]] – part of the [[Canadian Shield]] that extends into the northern United States [[Great Lakes (North America)|Great Lakes]] area.
* [[Atlantic Plain]] – the coastal regions of the eastern and southern parts include the continental shelf, the [[East Coast of the United States|Atlantic Coast]] and the [[U.S. Gulf Coast|Gulf Coast]].
* [[Appalachian Highlands]] – lying on the eastern side of the United States, it includes the [[Appalachian Mountains]], the [[Watchung Mountains]], the [[Adirondacks]] and [[New England]] province originally containing the Great Eastern Forest, a stretch of mixed temperature and subtropical montane forests, some of which are rainforests.
* [[Interior Plains]] – part of the interior continental United States, it includes the [[Great Plains]], as well as a number of highland and mountainous regions, like the [[Black Hills]], dense cave systems, painted hills and badland features.
* [[Interior Highlands]] – also part of the interior continental United States, this division includes the [[Ozark]] Plateau, the [[Ouachita Mountains]], and other smaller mountain systems. This region is located largely in the warm temperate/subtropical moist and dry forest biomes.
* [[Rocky Mountains|Rocky Mountain System]] – one branch of the [[American Cordillera]] system lying far inland in the western states.
* [[Geography of the United States Intermontane Plateaus|Intermontane Plateaus]] – also divided into the [[Columbia Plateau]], the [[Colorado Plateau]] and the [[Basin and Range Province]], it is a system of plateaus, basins, ranges and gorges between the Rocky and Pacific Mountain Systems. It is the setting for the [[Grand Canyon]], the [[Great Basin]] and [[Death Valley]].
* [[Pacific Coast Ranges|Pacific Mountain System]] – the coastal mountain ranges and features in the [[West Coast of the United States|west coast of the United States]].
[[File:MountMcKinley BA.jpg|thumb|[[Denali]], federally designated as Mount McKinley, in [[Alaska]], is the tallest mountain in North America, at {{convert|20310|ft|m|1|abbr=on}}.]]
[[File:Grand Canyon from Moran Point.jpeg|thumb|[[The Grand Canyon]], seen here from Moran Point, is among the most visited locations in the country.]]
The [[eastern United States]] has a varied topography. A broad, flat coastal plain lines the Atlantic and Gulf shores from the Texas-Mexico border to [[New York City]], and includes the Florida peninsula. This broad coastal plain and [[barrier islands]] make up the widest and longest beaches in the United States, much of it composed of soft, white sands. The [[Florida Keys]] are a string of [[Coral island|coral islands]] that reach the southernmost city on the United States mainland at [[Key West]] in [[South Florida]].
Areas further inland feature rolling hills, mountains, and a diverse collection of temperate and subtropical moist and wet forests. Parts of interior Florida and South Carolina are also home to [[sandhill]] communities. The [[Appalachian Mountains]] form a line of low mountains separating the eastern seaboard from the [[Great Lakes Basin|Great Lakes]] and the [[Mississippi River|Mississippi basins]]. [[New England]] features rocky seacoasts and rugged mountains with peaks up to 6,200 feet and valleys dotted with rivers and streams. Offshore islands dot the Atlantic and Gulf coasts. A recent global remote sensing analysis suggested that there were 6,622 km² of [[Mudflat|tidal flats]] in the United States, making it the 4th ranked country in terms of tidal flat area.<ref>{{cite journal |last1=Murray |first1=N.J. |last2=Phinn |first2=S.R. |last3=DeWitt |first3=M. |last4=Ferrari |first4=R. |last5=Johnston |first5=R. |last6=Lyons |first6=M.B. |last7=Clinton |first7=N. |last8=Thau |first8=D. |last9=Fuller |first9=R.A. |title=The global distribution and trajectory of tidal flats |journal=Nature |date=2019 |volume=565 |issue=7738 |pages=222–225 |doi=10.1038/s41586-018-0805-8 |pmid=30568300 |s2cid=56481043 |url=https://www.nature.com/articles/s41586-018-0805-8|url-access=subscription }}</ref>
The five [[Great Lakes]] are located in the north-central portion of the country, four of them forming part of the border with Canada; only [[Lake Michigan]] is situated entirely within the United States. The [[Southeastern United States|southeast United States]], generally stretching from the [[Ohio River]] southwards, includes a variety of warm temperate and subtropical moist and wet forests, as well as warm temperate and subtropical dry forests nearer the [[Great Plains]] in the west of the region. West of the Appalachians lies the lush Mississippi River basin and two large eastern tributaries, the Ohio River and the [[Tennessee River]]. The Ohio and [[Tennessee Valley|Tennessee]] valleys and the [[Midwestern United States|Midwest]] consist largely of rolling hills, interior highlands and small mountains, jungle-like marsh and swampland near the Ohio River, and productive farmland, stretching south to the [[Gulf Coast of the United States|Gulf Coast]]. The Midwest also has a vast amount of cave systems.
The Great Plains lie west of the Mississippi River and east of the [[Rocky Mountains]]. A large portion of the country's agricultural products are grown in the Great Plains. Before their general conversion to farmland, the Great Plains were noted for their extensive grasslands, from [[tallgrass prairie]] in the eastern plains to [[shortgrass prairie|shortgrass steppe]] in the western [[High Plains (United States)|High Plains]]. Elevation rises gradually from less than a few hundred feet near the Mississippi River to more than a mile high in the High Plains. The generally low relief of the plains is broken in several places, most notably in the [[The Ozarks|Ozark]] and [[Ouachita Mountains]], which form the [[U.S. Interior Highlands]], the only major mountainous region between the Rocky Mountains and the Appalachian Mountains.<ref>{{cite web | url=http://www.srs.fs.usda.gov/4106/about/HotSpringsOffice.htm | title=Managing Upland Forests of the Midsouth | publisher=United States Forestry Service | access-date=2007-10-13 | url-status=dead | archive-url=https://web.archive.org/web/20071017222856/http://srs.fs.usda.gov/4106/about/HotSpringsOffice.htm | archive-date=2007-10-17 }}</ref><ref>{{cite web|url=http://tapestry.usgs.gov/physiogr/physio.html |title=A Tapestry of Time and Terrain: The Union of Two Maps – Geology and Topography |publisher=United States Geological Survey |access-date=2007-10-13 |url-status=dead |archive-url=https://web.archive.org/web/20060515044037/http://tapestry.usgs.gov/physiogr/physio.html |archive-date=2006-05-15 }}</ref>
The Great Plains come to an abrupt end at the Rocky Mountains. The Rocky Mountains form a large portion of the [[Western U.S.]], entering from Canada and stretching nearly to Mexico. The Rocky Mountain region is the highest region of the United States by average elevation. The Rocky Mountains generally contain fairly mild slopes and wider peaks compared to some of the other great mountain ranges, with a few exceptions, including the [[Teton Range]] in [[Wyoming]] and the [[Sawatch Range]] in [[Colorado]]. The highest peaks of the Rockies are found in Colorado, the tallest peak being [[Mount Elbert]] at {{convert|14440|ft|m|abbr=on}}. Instead of being one generally continuous and solid mountain range, it is broken up into several smaller intermittent mountain ranges, forming a large series of basins and valleys.
West of the Rocky Mountains lies the [[Intermontane Plateaus]], also known as the [[Intermountain West]], a large, arid desert lying between the Rockies and the [[Cascade Range|Cascades]] and [[Sierra Nevada]] ranges. The large southern portion, known as the [[Great Basin]], consists of salt flats, drainage basins, and many small north–south mountain ranges. The [[Southwestern United States|Southwest]] is predominantly a low-lying desert region. A portion known as the [[Colorado Plateau]], centered around the [[Four Corners]] region, is considered to have some of the most spectacular scenery in the world. It is accentuated in such national parks as [[Grand Canyon National Park|Grand Canyon]], [[Arches National Park|Arches]], [[Mesa Verde National Park|Mesa Verde]] and [[Bryce Canyon National Park|Bryce Canyon]], among others. Other smaller Intermontane areas include the [[Columbia Plateau]], which covers eastern [[Washington (state)|Washington state]], western [[Idaho]] and northeast [[Oregon]] and the [[Snake River Plain]] in southern Idaho.
The Intermontane Plateaus come to an end at the Cascade Range and the Sierra Nevada. The Cascades consist of largely intermittent, volcanic mountains, many rising prominently from the surrounding landscape. The Sierra Nevada, further south, is a high, rugged, and dense mountain range. It contains the highest point in the contiguous 48 states, [[Mount Whitney]] ({{convert|14505|ft|0|abbr=on|disp=or}}). It is located at the boundary between [[California|California's]] [[Inyo County, California|Inyo]] and [[Tulare County, California|Tulare]] counties, just {{convert|84.6|mi|1|abbr=on|disp=or}} west-northwest of the lowest point in North America at the [[Badwater Basin]] in [[Death Valley National Park]] at {{convert|279|ft|abbr=on|disp=or}} below sea level.<ref name=NED>{{cite web|url=https://catalog.data.gov/dataset/usgs-national-elevation-dataset-ned-1-meter-downloadable-data-collection-from-the-national-map-|title=USGS National Elevation Dataset (NED) 1 meter Downloadable Data Collection from The National Map 3D Elevation Program (3DEP) – National Geospatial Data Asset (NGDA) National Elevation Data Set (NED)|publisher=[[United States Geological Survey]]|date=September 21, 2015|access-date=September 22, 2015|archive-date=March 25, 2019|archive-url=https://web.archive.org/web/20190325085854/https://catalog.data.gov/dataset/usgs-national-elevation-dataset-ned-1-meter-downloadable-data-collection-from-the-national-map-|url-status=dead}}</ref> These areas contain some spectacular scenery as well, as evidenced by such national parks as [[Yosemite National Park|Yosemite]] and [[Mount Rainier National Park|Mount Rainier]]. West of the Cascades and Sierra Nevada is a series of valleys, such as the [[Central Valley (California)|Central Valley]] in California and the [[Willamette Valley]] in Oregon. Along the coast is a series of low mountain ranges known as the [[Pacific Coast Ranges]].
Alaska contains some of the most dramatic scenery in the country. Tall, prominent mountain ranges rise up sharply from broad, flat tundra plains. On the islands off the south and southwest coast are many volcanoes. Hawaii, far to the south of Alaska in the Pacific Ocean, is a chain of tropical, [[Volcanic island|volcanic islands]], popular as a tourist destination for many from [[East Asia]] and the mainland United States.
The territories of Puerto Rico and the U.S. Virgin Islands encompass a number of tropical isles in the northeastern [[Caribbean Sea]]. In the Pacific Ocean the territories of Guam and the Northern Mariana Islands occupy the limestone and volcanic isles of the Mariana archipelago, and American Samoa (the only populated US territory in the southern hemisphere) encompasses volcanic peaks and coral atolls in the eastern part of the [[Samoan Islands]] chain.{{refn|group=note|One island in American Samoa ([[Swains Island]]) is not in the Samoan Islands — it is in the [[Tokelau]] island chain.}}
The Atlantic coast of the United States is low, with minor exceptions. The Appalachian Highland owes its oblique northeast–southwest trend to [[Crustal deformation|crustal deformations]] which in very early geological time gave a beginning to what later came to be the Appalachian Mountain system. This system had its climax of deformation so long ago (probably in [[Permian]] time) that it has since then been very generally reduced to moderate or low [[Terrain|relief]]. It owes its present-day altitude either to renewed elevations along the earlier lines or to the survival of the most resistant rocks as residual mountains. The oblique trend of this coast would be even more pronounced but for a comparatively modern crustal movement, causing a depression in the northeast resulting in an encroachment of the sea upon the land. Additionally, the southeastern section has undergone an elevation resulting in the advance of the land upon the sea.
While the Atlantic coast is relatively low, the Pacific coast is, with few exceptions, hilly or mountainous. This coast has been defined chiefly by geologically recent crustal deformations, and hence still preserves a greater relief than that of the Atlantic. The low Atlantic coast and the hilly or mountainous Pacific coast foreshadow the leading features in the distribution of mountains within the United States.
The east coast Appalachian system, originally forest covered, is relatively low and narrow and is bordered on the southeast and south by an important coastal plain. The [[American cordillera|Cordilleran system]] on the western side of the continent is lofty, broad and complicated, having two branches, the Rocky Mountain System and the Pacific Mountain System. In between these mountain systems lie the [[Intermontane Plateaus]]. Both the [[Columbia River]] and [[Colorado River]] rise far inland near the easternmost members of the Cordilleran system, and flow through plateaus and intermontane basins to the ocean. Heavy forests cover the northwest coast, but elsewhere trees are found only on the higher ranges below the Alpine region. The intermontane valleys, plateaus and basins range from treeless to desert with the most arid region being in the southwest.
Elevation extremes:
*Lowest point: [[Death Valley]], [[Inyo County, California]] {{convert|-280|ft|m|1|abbr=on}}
*Highest point: [[Denali|Denali/Mount McKinley]], [[Denali Borough, Alaska]] {{convert|20310|ft|m|1|abbr=on}}
==Climate==
{{Main|Climate of the United States}}
[[File:US_50_states_Köppen_with_territories.png|thumb|The [[Köppen climate classification|Köppen climate types]] of the United States, including the five inhabited [[Territories of the United States|U.S. territories]])]]
[[File:Average precipitation in the lower 48 states of the USA.png|thumb|A map of average precipitation across the contiguous United States]]
Due to its large size and wide range of geographic features, the United States contains examples of nearly every global climate. The climate is subtropical in the [[Southern United States]], [[humid continental climate|continental]] in the north, tropical in [[Hawaii]] and southern [[Florida]], polar in Alaska, semiarid in the Great Plains west of the [[100th meridian west|100th meridian]], Mediterranean in coastal [[California]] and arid in the [[Great Basin]] and the [[Southwestern United States|Southwest]]. Its comparatively favorable agricultural climate contributed (in part) to the country's rise as a world power, with infrequent severe drought in the major agricultural regions, a general lack of widespread flooding, and a mainly temperate climate that receives adequate precipitation.
The main influence on U.S. weather is the [[jet stream|polar jet stream]] which migrates northward into Canada in the summer months, and then southward into the US in the winter months. The jet stream brings in large low-pressure systems from the northern [[Pacific Ocean]] that enters the US mainland over the Pacific Northwest. The [[Cascade Range]], [[Sierra Nevada (U.S.)|Sierra Nevada]], and [[Rocky Mountains]] pick up most of the moisture from these systems as they move eastward via the [[Precipitation (meteorology)#Orographic effects|orographic effect]], and they are greatly diminished by the time they reach the High Plains.
Once they move over the Great Plains, uninterrupted flat land allows them to reorganize and can lead to major clashes of air masses. In addition, moisture from the [[Gulf of Mexico]] is often drawn northward. When combined with a powerful jet stream, this can lead to violent thunderstorms, especially during spring and summer. Sometimes during winter, these storms can combine with another low-pressure system as they move up the East Coast and into the [[Atlantic Ocean]], where they intensify rapidly.
These storms are known as [[Nor'easter]]s and often bring widespread, heavy rain, wind, and snowfall to [[New England]]. The uninterrupted grasslands of the Great Plains also lead to some of the most extreme climate swings in the world. Temperatures can rise or drop rapidly, winds can be extreme, and the flow of heat waves or Arctic air masses often advance uninterrupted through the plains.
The [[Great Basin]] and [[Columbia Plateau]] (the [[Intermontane Plateaus]]) are arid or semiarid regions that lie in the rain shadow of the [[Cascade Mountains|Cascades]] and [[Sierra Nevada (U.S.)|Sierra Nevada]]. Precipitation averages less than {{convert|15|in|cm|0}}. The Southwest is a hot desert, with temperatures exceeding {{convert|100|°F|1}} for several weeks at a time in summer. The Southwest and the Great Basin are also affected by the [[monsoon]] from the [[Gulf of California]] from July to September, which brings localized but often severe thunderstorms to the region.
Much of California consists of a [[Mediterranean climate]], with sometimes excessive rainfall from October–April and nearly no rain the rest of the year. In the [[Pacific Northwest]] rain falls year-round but is much heavier during winter and spring. The mountains of the west receive abundant precipitation and very heavy snowfall. The Cascades are one of the snowiest places in the world, with some places averaging over {{convert|600|in|cm|0}} of snow annually, but the lower elevations closer to the coast receive very little snow.
Florida has a [[subtropical climate]] in the northern part of the state and a [[tropical climate]] in the southern part of the state. Summers are wet and winters are dry in Florida. Annually, much of Florida and the deep southern states is frost-free. The mild winters of Florida allow a massive tropical fruit industry to thrive in the central part of the state, making the US second to only Brazil in [[citrus production]] worldwide.
Another significant (but localized) weather effect is [[lake-effect snow]] that falls south and east of the [[Great Lakes]], especially in the hilly portions of the [[Upper Peninsula]] of [[Michigan]] and on the [[Tug Hill Plateau]] in [[New York (state)|New York]]. The lake effect dumped well over {{convert|5|ft|m|2}} of snow in the area of Buffalo, New York throughout the 2006–2007 winter. The [[Wasatch Front]] and [[Wasatch Range]] in [[Utah]] can also receive significant lake effect accumulations from the [[Great Salt Lake]].<gallery>
File:Climate map USA.PNG|'''Climate map USA'''
File:Mitchell Map-06full2.jpg|'''Mitchell Map-06full2'''
</gallery>
===Extremes===
{{see also|U.S. state temperature extremes}}
[[File:Fagatogo Dock.jpg|thumb|[[Pago Pago Harbor]] in [[American Samoa]] has the highest annual rainfall of any harbor in the world.<ref name="LonelyplanetAS">{{cite web|url=https://www.lonelyplanet.com/american-samoa/tutuila/attractions/rainmaker-mountain/a/poi-sig/1456093/362248|author=Lonely Planet|title=Rainmaker Mountain in Tutuila|website=Lonely Planet|access-date=September 1, 2019|archive-url=https://web.archive.org/web/20171019004653/https://www.lonelyplanet.com/american-samoa/tutuila/attractions/rainmaker-mountain/a/poi-sig/1456093/362248|archive-date=October 19, 2017|url-status=live}}</ref>]]
In northern [[Alaska]], [[tundra]] and [[arctic]] conditions predominate, and the temperature has fallen as low as {{convert|-80|°F|1}}.<ref>Williams, Jack [https://www.usatoday.com/weather/wcstates.htm Each state's low temperature record], ''USA today'', ''URL accessed 13 June 2006.''</ref> On the other end of the spectrum, [[Death Valley National Park|Death Valley, California]] once reached {{convert|134|°F|1}}, the highest temperature ever recorded on Earth.<ref name="Death_Valley">{{cite web | url = http://www.nps.gov/deva/planyourvisit/upload/Weather.pdf | archive-url = https://web.archive.org/web/20061010233536/http://www.nps.gov/deva/planyourvisit/upload/Weather.pdf | url-status = dead | archive-date = October 10, 2006 | title = Weather and Climate | access-date = October 5, 2006 |date=January 2002 | work = Official website for Death Valley National Park | publisher = National Park Service U. S. Department of the Interior | pages = 1–2}}</ref><ref>{{cite web|url=http://www.wmo.int/pages/mediacentre/press_releases/pr_956_en.html |title=WMO Press release No. 956 |date=September 13, 2012 |publisher=World Meteorological Organization |access-date=April 10, 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160406053728/http://www.wmo.int/pages/mediacentre/press_releases/pr_956_en.html |archive-date=April 6, 2016 }}</ref>
On average, the mountains of the western states receive the highest levels of snowfall on Earth. The greatest annual snowfall level is at [[Mount Rainier]] in [[Washington (state)|Washington]], at {{convert|692|in|cm|0}}; the record there was {{convert|1122|in|cm|0}} in the winter of 1971–72. This record was broken by the Mt. Baker Ski Area in northwestern Washington which reported {{convert|1140|in|cm|0}} of snowfall for the 1998–99 snowfall season. Other places with significant snowfall outside the Cascade Range are the [[Wasatch Mountains]] in [[Utah]], the [[San Juan Mountains]] in [[Colorado]], and the [[Sierra Nevada (U.S.)|Sierra Nevada]] in [[California]].
In the east, the region near the Great Lakes and the mountains of the Northeast receive the most snowfall, although they do not near snowfall levels in the western United States. Along the northwestern Pacific coast, rainfall is greater than anywhere else in the continental U.S., with [[Quinault Rainforest]] in Washington having an average of {{convert|137|in|cm|0}}.<ref>National Atlas, [http://www.nationalatlas.gov/mld/prism0p.html Average Annual Precipitation, 1961–1990] {{webarchive|url=https://web.archive.org/web/20060928220607/http://nationalatlas.gov/mld/prism0p.html |date=2006-09-28 }}, ''URL accessed 15 June 2006.''</ref> Hawaii receives even more, with {{convert|404|in|cm|0}} measured annually in the [[Big Bog, Maui|Big Bog]], in [[Maui]].<ref>{{cite web| url = https://scholarspace.manoa.hawaii.edu/handle/10125/36675| title = ScholarSpace at University of Hawaii at Manoa: Climatology of Haleakalā| date = July 2015| hdl = 10125/36675| last1 = Longman| first1 = Ryan J.| last2 = Giambelluca| first2 = Thomas W.| last3 = Nullet| first3 = Michael A.| last4 = Loope| first4 = Lloyd L.}} R.J. Longman and T.W. Giambelluca. Climatology of Haleakala. Climatology of Haleakalā Technical Report No. 193. Volume 1, Issue 1. Pages 105–106. 2015. Retrieved September 1, 2019.</ref> [[Pago Pago Harbor]] in [[American Samoa]] is the rainiest harbor in the world (because of the 523 meter [[Rainmaker Mountain]]).<ref name="LonelyplanetAS"/> The [[Mojave Desert]], in the southwest, is home to the driest locale in the U.S. [[Yuma, Arizona]], has an average of {{convert|2.63|in|cm}} of [[precipitation (meteorology)|precipitation]] each year.<ref>Hereford, Richard, et al., [http://pubs.usgs.gov/fs/fs117-03/ Precipitation History of the Mojave Desert Region, 1893–2001], ''U.S. Geological Survey, Fact Sheet 117-03'', ''URL accessed 13 June 2006.''</ref>
In central portions of the U.S., [[tornado]]es are more common than anywhere else on Earth<ref>NOVA, [https://www.pbs.org/wgbh/nova/tornado/country.html Tornado Heaven], ''Hunt for the Supertwister'', ''URL accessed 15 June 2006.''</ref> and touch down most commonly in the spring and summer. Deadly and destructive [[hurricane]]s occur almost every year along the Atlantic seaboard and the Gulf of Mexico. The Appalachian region and the Midwest experience the worst floods, though virtually no area in the U.S. is immune to flooding. The Southwest has the worst droughts; one is thought to have lasted over 500 years and to have hurt [[Ancestral Pueblo peoples]].<ref>O'Connor, Jim E. and John E. Costa, [http://pubs.usgs.gov/circ/2003/circ1245/ Large Floods in the United States: Where Thley Happen and Why], ''U.S. Geological Survey Circular 1245'', ''URL accessed 13 June 2006.''</ref> The West is affected by large wildfires each year.
==Natural disasters==
{{see also|List of natural disasters in the United States}}
[[File:Dimmitt Tornado1 - NOAA.jpg|thumb|A powerful tornado near [[Dimmitt, Texas]] on June 2, 1995]]
The United States is affected by a variety of [[natural disaster]]s yearly. Although drought is rare, it has occasionally caused major disruption, such as during the [[Dust Bowl]] (1931–1942). Farmland failed throughout the Plains, entire regions were substantially depopulated, and dust storms ravaged the land.
===Tornadoes and hurricanes===
{{main|Tornadoes in the United States|Hurricanes in the United States}}
[[File:Hurricane katrina damage gulfport mississippi.jpg|thumb|Total devastation in [[Gulfport, Mississippi]] caused by storm surge from [[Hurricane Katrina]] in 2005]]
According to a 2023 Gallup survey, around one in three Americans said that they directly experienced a severe weather condition over the previous two years.<ref>{{Cite web |last=Horn-Muller |first=Ayurella |date=2023-04-15 |title=Climate-displaced Americans face discrimination |url=https://www.axios.com/2023/04/14/climate-displaced-americans-discrimination |access-date=2023-04-19 |website=Axios |language=en}}</ref> The Great Plains and Midwest, due to the contrasting air masses, see frequent severe thunderstorms and tornado outbreaks during spring and summer with around 1,000 tornadoes occurring each year.<ref>[http://www.nssl.noaa.gov/primer/tornado/tor_climatology.html NSSL: Severe Weather 101] {{Webarchive|url=https://web.archive.org/web/20120320044359/http://www.nssl.noaa.gov/primer/tornado/tor_climatology.html |date=2012-03-20 }}. Nssl.noaa.gov. Retrieved on 2013-07-29.</ref> The strip of land from north [[Texas]] north to [[Kansas]] and [[Nebraska]] and east into [[Tennessee]] is known as [[Tornado Alley]], where many houses have tornado shelters and many towns have tornado sirens, due to the very frequent tornado formation in the region.
Hurricanes are another natural disaster found in the US, which can hit anywhere along the [[U.S. Gulf Coast|Gulf Coast]] or the [[East Coast of the United States|Atlantic Coast]] as well as Hawaii in the Pacific Ocean. Particularly at risk are the central and southern [[Texas]] coasts, the area from southeastern [[Louisiana]] east to the [[Florida Panhandle]], peninsular [[Florida]], and the [[Outer Banks]] of [[North Carolina]], although any portion of the coast could be struck. The [[U.S. territories]] and possessions in the [[Caribbean]], including [[Puerto Rico]] and the [[U.S. Virgin Islands]], are also vulnerable to hurricanes due to their ___location in the [[Caribbean Sea]].
Hurricane season runs from June 1 to November 30, with a peak from mid-August through early October. Some of the more devastating hurricanes have included the [[Galveston Hurricane of 1900]], [[Hurricane Andrew]] in 1992, [[Hurricane Katrina]] in 2005, and [[Hurricane Harvey]] and [[Hurricane Maria]] in 2017.
Hurricanes (known as cyclones in the Pacific Ocean) fail to make landfall on the Pacific Coast of the United States due to water temperatures being too cool to sustain them. However, the remnants of tropical cyclones from the Eastern Pacific occasionally impact the western United States, bringing moderate to heavy rainfall.
===Flooding===
Occasional severe flooding is experienced in the United States. Significant floods throughout history include the [[Great Mississippi Flood of 1927]], the [[Great Flood of 1993]], and widespread flooding and mudslides caused by the 1982–83 [[El Niño]] event in the western United States. Flooding is still prevalent, mostly on the Eastern Coast, during hurricanes or other inclement weather, for example in 2012, when [[Hurricane Sandy]] devastated the region. Localized flooding can, however, occur anywhere, and mudslides from heavy rain can cause problems in any mountainous area, particularly the Southwest. Large stretches of desert shrub in the west can fuel the spread of [[wildfire]]s. The narrow canyons of many mountain areas in the west and severe thunderstorm activity during the summer lead to [[flash flood]]s as well, which can sometimes be devastating, while [[nor'easter]] snowstorms can bring activity to a halt throughout the Northeast (although heavy snowstorms can occur almost anywhere).
==
The West Coast of the continental United States makes up part of the [[Pacific Ring of Fire]], an area of heavy tectonic and volcanic activity that is the source of 90% of the world's earthquakes.<ref>{{Cite web |title=Cool Earthquake Facts {{!}} U.S. Geological Survey |url=https://www.usgs.gov/programs/earthquake-hazards/cool-earthquake-facts#:~:text=The%20%E2%80%9CRing%20of%20Fire%E2%80%9D%20also,the%20world's%20earthquakes%20occur%20there. |access-date=2023-09-30 |website=www.usgs.gov}}</ref> The American Northwest sees the highest concentration of active volcanoes in the United States, in [[Washington (state)|Washington]], [[Oregon]] and [[northern California]] along the [[Cascade Mountains]]. There are several active volcanoes located in the islands of Hawaii, including Kilauea in ongoing eruption since 1983, but they do not typically adversely affect the inhabitants of the islands. There has not been a major life-threatening eruption on the Hawaiian Islands since the 17th century. Volcanic eruptions can occasionally be devastating, such as in the [[1980 eruption of Mount St. Helens]] in Washington.
The Ring of Fire makes [[California]] and southern [[Alaska]] particularly vulnerable to [[earthquake]]s. Earthquakes can cause extensive damage, such as the [[1906 San Francisco earthquake]] or the 1964 [[Good Friday earthquake]] near [[Anchorage, Alaska]]. California is well known for seismic activity and requires large structures to be [[Earthquake resistant structures|earthquake resistant]] to minimize loss of life and property.<ref>{{cite web| url = https://earthquake.usgs.gov/learn/publications/saferstructures/| url-status = dead| archive-url = https://web.archive.org/web/20100511070408/http://earthquake.usgs.gov/learn/publications/saferstructures/| archive-date = 2010-05-11| title = Building Safer Structures}}</ref> Outside of devastating earthquakes, California experiences minor earthquakes on a regular basis.
There have been about 100 significant earthquakes annually from 2010 to 2012. Past averages were 21 a year. This is believed to be due to the deep disposal of wastewater from [[fracking]]. None have exceeded a magnitude of 5.6, and no one has been killed.<ref>{{cite news | first=Dan | last=Vergano | title=Study:Earthquake increase tied to energy boom | url=https://www.usatoday.com/story/news/nation/2013/07/11/injection-induced-earthquakes/2508499/| newspaper=[[The Burlington Free Press]] | ___location=[[Burlington, Vermont]] | pages= 10A | date=July 12, 2013 | access-date=July 14, 2013}}</ref>
===Other natural disasters===
Other natural disasters include [[tsunami]]s around the Pacific Basin, mudslides in California, and forest fires in the western half of the contiguous U.S. Although drought is relatively rare, it has occasionally caused major economic and social disruption, such as during the [[Dust Bowl]] (1931–1942), which resulted in widespread crop failures and dust storms, beginning in the southern Great Plains and reaching to the Atlantic Ocean.
=== Consequences ===
According to report by U.S. [[Census Bureau]], in 2022 natural disasters led to the forced displacement of 3.3 million people, more than 1.3% of the U.S. adult population, with half of the displacements being caused by the [[Tropical cyclone|hurricanes]]. The survey-report stated that in [[Florida]], the devastation caused by Hurricanes Ian and Nicole resulted in the relocation of around 1 million people, or about one in every 17 adult residents. In [[Louisiana]], where inhabitants were still dealing with the devastating results of [[Hurricane Ida]] the year before, more than 409,000 people, or almost one in every eight residents, were moved. Despite this, the [[Louisiana]] state saw a relatively calm hurricane season in 2022.<ref>{{Cite web |agency=Associated Press |date=2023-01-06 |title=3.3 million US adults displaced by natural disasters in past year – survey |url=https://www.theguardian.com/us-news/2023/jan/06/us-adults-displaced-natural-disasters-survey-census-bureau |access-date=2023-01-11 |website=the Guardian |language=en}}</ref>
==Public lands==
[[File:Territorial waters - United States.svg|thumb|Exclusive economic zones of the United States, including the nation's [[insular areas]]]]
The United States holds many areas for the use and enjoyment of the public. These include [[national park]]s, [[National monument (United States)|national monuments]], [[United States National Forest|national forests]], [[Strict Nature Reserve/Wilderness Area|wilderness areas]], and other areas. For lists of areas, see the following articles:
*[[List of national parks of the United States]]
*[[List of
*[[List of
*[[List of
== Human ==
{{Main|Demography of the United States}}
In terms of [[human geography]], the United States is inhabited by a [[Multiculturalism|diverse set of ethnicities and cultures]].
==See also==
{{
{{colbegin}}
*[[
*[[Geographic centers of the United States]]
*
*
*
*[[List of extreme points of the United States]]
*[[
*[[List of islands of the United States]]
*[[List of
*[[
*[[List of North American deserts]]
*[[List of rivers of the United States]]
*[[List of snowiest places in the United States by state]]
*[[Protected areas of the United States]]
*[[Public Land Survey System]]
*[[
===Regions===
*[[Historic regions of the United States]]
*[[List of regions of the United States]]
===Mountains===
*[[List of mountain peaks of the United States]]
*[[List of mountains of the United States]]
{{colend}}
==Notes==
{{reflist|group=note}}
==References==
{{Reflist}}
==Further reading==
* Brown, Ralph Hall, ''Historical Geography of the United States'', New York : Harcourt, Brace, 1948
* Stein, Mark, ''How the States Got Their Shapes'', New York : Smithsonian Books/Collins, 2008. {{ISBN|978-0-06-143138-8}}
==
{{Commons category}}
*[https://web.archive.org/web/20030209053037/http://tapestry.usgs.gov/ USGS: Tapestry of Time and Terrain]
*[http://www.
*[https://web.archive.org/web/20081205020547/http://www.nationalatlas.gov/ National Atlas of the United States of America]
*[https://www.burningcompass.com/countries/united-states/states/us-states-and-capitals-map.html US Map]
{{U.S. political divisions geographies}}
{{Regions of the United States}}
{{United States topics}}
{{Geography of North America}}
{{North America topic|Climate of}}
{{authority control}}
{{DEFAULTSORT:Geography Of The United States}}
[[Category:Geography of the United States| ]]
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