List of longest rivers of the United States (by main stem)


The longest rivers of the United States include 38 that have
main stem In hydrology Hydrology (from Greek: wikt:ὕδωρ, ὕδωρ, "hýdōr" meaning "water" and wikt:λόγος, λόγος, "lógos" meaning "study") is the scientific study of the movement, distribution, and management of water on Earth and othe ...
s of at least long. The main stem is "the primary downstream segment of a river, as contrasted to its tributaries". The
United States Geological Survey The United States Geological Survey, abbreviated USGS and formerly simply known as the Geological Survey, is a scientific government agency, agency of the Federal government of the United States, United States government. The scientists of the ...
(USGS) defines a main-stem segment by listing coordinates for its two end points, called the ''source'' and the ''mouth''. Some well-known rivers like the
, and
are not included in this list because their main stems are shorter than 500 miles. Seven rivers in this list cross or form international boundaries. Two—the
Yukon Yukon ( ; ; formerly called Yukon Territory and sometimes referred to as The Yukon) is the smallest and westernmost of Provinces and territories of Canada, Canada's three territories. It also is the least populated province or territory in Cana ...

Columbia Columbia may refer to: * Columbia (personification), the historical female national personification of the United States, and a poetic name for the Americas Places North America Natural features * Columbia Plateau, a geologic and geographic regio ...

rivers—begin in Canada and flow into the United States. Three—the
Milk Milk is a nutrient-rich liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfeeding, breastfed human infants) before they are able to digestion, digest solid food. Earl ...
Saint Lawrence Saint Lawrence or Laurence ( la, Laurentius, lit. "laurelled"; 31 December AD 225 – 10 August 258) was one of the seven deacons of the city of Rome , established_title = Founded , established_date = 753 BC , founder ...
rivers and the
Red River of the North The Red River (french: rivière Rouge or , American English American English (AmE, AE, AmEng, USEng, en-US), sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United Stat ...

Red River of the North
—begin in the United States and flow into Canada. Of these, only the Milk River crosses the international border twice, leaving and then re-entering the United States. Two rivers, the
Colorado Colorado (, other variants) is a state in the Mountain states, Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the wester ...

and the
Rio Grande The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte and as the Río Bravo, is one of the principal river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another riv ...

Rio Grande
, begin in the United States and flow into or form a border with Mexico. In addition, the
drainage basin A drainage basin is any area of land where precipitation collects and drains off into a common outlet, such as into a river, bay, or other body of water. The drainage basin includes all the surface water from surface runoff, rain runoff, snowme ...

drainage basin
s of the
Mississippi Mississippi () is a state State may refer to: Arts, entertainment, and media Literature * ''State Magazine'', a monthly magazine published by the U.S. Department of State * The State (newspaper), ''The State'' (newspaper), a daily newspaper ...

Missouri river The Missouri River is the longest river in North America. Rising in the Rocky Mountains of the Eastern Centennial Mountains of Southwestern Montana, the Missouri flows east and south for before entering the Mississippi River north of St. Louis, ...
s extend into Canada, and the basin of the
Gila River The Gila River (; O'odham ima Keli Akimel or simply Akimel, Quechan: Haa Siʼil) is a -long tributary A tributary or affluent is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not ...
extends into Mexico. Sources report hydrological quantities with varied precision. Biologist and author
Ruth Patrick Ruth Myrtle Patrick (November 26, 1907 – September 23, 2013) was an American botanist and limnologist specializing in diatoms and freshwater ecology. She authored more than 200 scientific papers, developed ways to measure the health of freshwate ...
, describing a table of high-discharge U.S. rivers, wrote that data on discharge, drainage area, and length varied widely among authors whose works she consulted. "It seems," she said, "that the wisest course is to regard data tables such as the present one as showing the general ranks of rivers, and not to place too much importance on minor (10–20%) differences in figures."


The primary source for watershed and discharge data in the table below is ''Rivers of North America''. Conflicting data from other sources, if the difference is greater than 10 percent, is reported in the notes. Discharge refers to the flow at the mouth. In the "States, provinces, and image" column, the superscripts "s" and "m" indicate "source" and "mouth". Non-U.S. states appear in italics. Except in the "States, provinces, and image" column, abbreviations are as follows: "km" for "kilometer", "mi" for "mile", "s" for "second", "m" for "meter", and "ft" for "foot".


Image:Longest Rivers of the US with labels fixed again 2.jpg, center, 780px, Map of North America showing all rivers on this list

See also

* List of longest rivers in the United States by state **List of longest streams of Idaho **List of longest streams of Minnesota **List of longest streams of Oregon * List of rivers by length



Works cited

* * {{featured list Lists of longest rivers, United States Lists of rivers of the United States United States-related lists of superlatives, Rivers