Thecontiguous United States, also referred to as theconterminous United States, consists of the 48 adjoiningU.S. states and theDistrict of Columbia of theUnited States in centralNorth America.[1][2] The term excludes the only two non-contiguous states, which areAlaska andHawaii (they are also the last two states to beadmitted to the Union), and all other offshoreinsular areas, such as theU.S. territories ofAmerican Samoa,Guam, theNorthern Mariana Islands,Puerto Rico, and theU.S. Virgin Islands.[3][4] The colloquial term "Lower 48"[5] is also used, especially in relation to Alaska.
The related but distinct termcontinental United States includesAlaska, which is also on North America, but separated from the 48 states byBritish Columbia in Canada, but excludesHawaii and all the insular areas in theCaribbean and thePacific.[1][6]
The greatest distance on agreat-circle route is entirely within the contiguous U.S. is 2,802 miles (4,509 km), coast-to-coast betweenFlorida and theWashington state;[7] the greatest north–south line is 1,650 miles (2,660 km).[8] The contiguous United States occupies an area of 3,119,884.69 square miles (8,080,464.3 km2). Of this area, 2,959,064.44 square miles (7,663,941.7 km2) is actual land, composing 83.65 percent of the country's total land area, and is comparable in size to the area of Australia.[9] Officially, 160,820.25 square miles (416,522.5 km2) of the contiguous United States is water area, composing 62.66 percent of the nation's total water area.
The contiguous United States, if it were a country, would be fifth on thelist of countries and dependencies by area, behindRussia,Canada,China, andBrazil. However, the total area of the United States, including Alaska and Hawaii, ranks third or fourth. Brazil is 431,000 square kilometers (166,000 sq mi) larger than the contiguous United States, but smaller than the entire United States including Alaska, Hawaii and overseas territories. The2020 U.S. census population of the area was 328,571,074, comprising 99.13 percent of the nation's total population, and a density of 111.04 inhabitants/sq mi (42.872/km2), compared to 93.844/sq mi (36.233/km2) for the nation as a whole.[10]
Whileconterminous U.S. has the precise meaning ofcontiguous U.S. (both adjectives meaning "sharing a common boundary"), other terms commonly used to describe the 48 contiguous states have a greater degree of ambiguity.
BecauseAlaska is also a part ofNorth America, the termcontinental United States also includes that state, so the term is qualified with the explicit inclusion of Alaska to resolve any ambiguity.[3][11][12][13] On May 14, 1959, theUnited States Board on Geographic Names issued the following definitions based partially on the reference in the Alaska Omnibus Bill, which defined the continental United States as "the 49 States on the North American Continent and the District of Columbia..." The Board reaffirmed these definitions on May 13, 1999.[1] However, even before Alaska became a state, it was properly included within the continental U.S. due to being anincorporated territory.[14]
The termmainland United States is sometimes used synonymously withcontinental United States, but technically refers only to those parts of states connected to the landmass of North America, thereby excluding not onlyHawaii and overseasinsular areas, but also islands which are part of continental states but separated from the mainland, such as theAleutian Islands (Alaska),San Juan Islands (Washington), theChannel Islands (California),the Keys (Florida), thebarrier islands (Gulf andEast Coast states), andLong Island (New York).[15]
CONUS, a technical term used by theU.S. Department of Defense,General Services Administration,NOAA/National Weather Service, and others, has been defined both as the continental United States, and as the 48 contiguous states.[16][17] The District of Columbia is not always specifically mentioned as being part ofCONUS.[17]
OCONUS is derived from CONUS withO for outside added, thus referring to Outside of Continental United States.[16][18]
The termlower 48 is also used to refer to the conterminous United States. TheNational Geographic style guide recommends the use ofcontiguous orconterminous United States instead oflower 48 when the 48 states are meant, unless used in the context of Alaska.[5][19] Almost all of Hawaii is south of the southernmost point of the conterminous United States in Florida.
DuringWorld War II, the first fournumbered Air Forces of theUnited States Army Air Forces (USAAF) were said to be assigned to theZone of the Interior by the American military organizations of the time—the future states ofAlaska andHawaii, then each onlyorganized incorporated territories of the Union, were respectively covered by theEleventh Air Force andSeventh Air Force during the war.[citation needed]
Residents of Alaska, Hawaii and off-shoreU.S. territories have unique labels for the contiguous United States because of their own locations relative to them.
The vast territory ofAlaska became the 49th state of the United States on January 3, 1959. Alaska is the northwest extremity of the North American continent, separated from theU.S. West Coast by theCanadian province ofBritish Columbia. The termLower 48 has, for many years, been a common Alaskan equivalent for "contiguous United States";[20][21] today, many Alaskans use the term"Outside" for those states, though some may use "Outside" to refer toany location not within Alaska.[22]
The territory ofHawaii, consisting of the entireHawaiian Islands archipelago except forMidway Atoll,[a] became the 50th state of the United States on August 21, 1959. It is the southernmost U.S. state, and the latest one to join the Union. Not part of any continent, Hawaii is located in thePacific Ocean, about 2,200 miles (3,541 km) from North America and almost halfway between North America andAsia. In Hawaii andoverseas American territories, for instance, the termsthe Mainland orU.S. Mainland are often used to refer to the 49 states in North America.[23][24]
Puerto Rico is anunincorporated territory of the United States located in the northeastCaribbean Sea, approximately 1,000 miles (1,609 km) southeast ofMiami,Florida. Puerto Ricans born in Puerto Rico are U.S. citizens and are free to move to the mainland United States. The termStateside Puerto Rican refers to residents of any U.S. state or the District of Columbia who were born in, or can trace their family ancestry to, Puerto Rico.[25]
TheU.S. Virgin Islands is aU.S. territory located directly to the east of Puerto Rico in the Caribbean Sea.[26] The term "stateside" is used to refer to the mainland, in relation to the U.S. Virgin Islands[27] (seeStateside Virgin Islands Americans).
American Samoa is aU.S. territory located in theSouth Pacific Ocean inPolynesia, south of the equator — it is 2,200 miles (3,500 km) southwest ofHawaii.[28] In American Samoa, the contiguous United States is called the "mainland United States" or "the states"; those not from American Samoa are calledpalagi (outsiders).[29]
Apart from off-shoreU.S. islands, a few continental portions of the contiguous United States are accessible by road only by traveling through Canada.Point Roberts, Washington;Elm Point, Minnesota; and theNorthwest Angle inMinnesota are three such places.Alburgh, Vermont, is not directly connected by land, but is accessible by road via bridges from within Vermont and from New York.[30] By contrast,Hyder, Alaska, is physically part of contiguous Alaska and its easternmost town, but the only practical access is by road through Canada or by seaplane.
The 48 contiguous states are:
In addition, theDistrict of Columbia is within the contiguous United States.
Contiguous United States: The 48 adjoining states and the District of Columbia.
The continental United States includes Alaska. [...] In Alaska context,lower forty-eight orlower 48 may be used. Do not hyphenatelower 48 as an adjective. The termoutside may be put in quotes on first reference if ambiguous. To distinguish the 48 states from the 49 or 50, usecontiguous orconterminous.
Thecontinental United States comprises the 48 contiguous, or conterminous, states plus Alaska.
Continental United States: The 48 adjoining states, Alaska and District of Columbia.
The Continental U.S. includes the lower 48 states as well as the State of Alaska, unless otherwise specified.
CONUS - "Continental United States." CONUS refers to the 48 contiguous states. It is not synonymous with United States. CONUS is acceptable on first reference."CONUS" seems to be used primarily by the American military and the Federal government and those doing business with them.
"OCONUS: Outside Continental United States
Use contiguous, or conterminous, for the 48 states. The continental United States comprises the 48 contiguous, or conterminous, states plus Alaska.
