What is the longest river in North America? | Reference.com What is the longest river in North America? A: Quick Answer Running between the state of Missouri and its source in Montana, the longest river in North America is the Missouri River. The river flows 2,341 miles until it reaches its mouth at the Mississippi River north of St. Louis. The Missouri River, just slightly longer than the Mississippi River, combines with it to form the fourth largest river system in the world after the Nile, Amazon and Yangtze rivers. Full Answer During the early years of North American exploration, the Missouri River was once thought to be the legendary "Northwest Passage," or connecting water route between the Atlantic and Pacific oceans across the North American continent. The Lewis and Clark Expedition, which occurred from 1804-1806, proved that belief to be wrong when they reached the western beginnings of the Missouri River in 1805. The river did, however, remain one of the primary routes for American expansion during the 1800s with a growing number of steamboats on the river providing transport to settlers and fur traders to what were then the western territories of the United States.

Nearly 530,000 square miles of watershed are drained by the Missouri River, which spans an area from the Great Plains to the Rocky Mountains. Approximately 10 million people live in the areas comprising the river's basin. The largest city in the Missouri River's watershed is Denver, Colo., with more than 600,000 inhabitants. Rivers in North America - North American Rivers, Major Rivers in Canada Us Mexico - Worldatlas.com Print this map Fraser: This river of British Columbia, Canada, begins in the Canadian Rockies near Yellowhead Pass, then flows in a variety of directions (generally south), finally turning west to empty into the Strait of Georgia, just south of Vancouver. It's (850 miles) (1,368 km) in length. Mackenzie: It's the longest river in Canada and dissects the Northwest Territories. It flows generally northwest into Mackenzie Bay and the Beaufort Sea. Sir Alexander MacKenzie discovered this historic river, and along its path are thick, green forests and dozens of major lakes. It's (1,200 miles) (1,800 km) in length.

If then combined with its tributaries - the Slave, Peace and Finlay rivers - it extends to (2,635 miles) (4,240 km), and becomes the second longest river in North America, second only to the Mississippi/Missouri river system combination at (3,877 miles) (6,236 km) in length. Mississippi: It is the major river of North America and the United States at (2,339 miles) (3,765 km) in length. It flows from northwestern Minnesota south to the Gulf of Mexico, just below the city of New Orleans. It is a significant transportation artery and when combined with its major tributaries (the Missouri and Ohio rivers) it becomes the third largest river system in the world at (3,877 miles) (6,236 km) in length. Missouri: It begins in southern Montana in the Rocky Mountains, first flowing north then generally southeast across the heart of the United States, ending at the Mississippi River, just to the north of St. Louis, Missouri. It is the longest river in the United States (2,500 miles) (4,023 km).

The 35 longest rivers in the USA The 35 longest rivers in the USA by USA TODAY | Published on October 28, 2014 35. Des Moines River, 525 miles. Begins in Minnesota, ends at the Mississippi River in Iowa. Thinkstock, Getty Images 34. Red River of the North, 550 miles. Begins on the border of North Dakota and Minnesota, ends in Canada. Kaye Kerr, Getty Images/iStockphoto 33. Sabine River, 553 miles. Begins in Texas, ends in the Gulf of Mexico by Louisiana. flickr.com/MichaelGras 32. Little Missouri River, 560 miles. Begins in Wyoming, ends in the Missouri River in North Dakota. Michael Thompson, Getty Images/iStockphoto 31. Niobrara River, 568 miles. Begins in Wyoming, ends in the Missouri River in Nebraska. flicker.com/brettwhaley 30. Smoky Hill River, 576 miles. Begins in Colorado, ends in the Kansas River in Kansas.

flickr.com/Mike Rodriquez 29. Tanana River, 584 miles. Begins in Alaska, ends in the Yukon River. Roman Krochuk 28. Sheyenne River, 591 miles. Begins in North Dakota, ends in the Red River of the North. flickr.com/jimmywayne 27. Gila River, 600 miles. Begins in New Mexico, ends in the Colorado River in Arizona. flickr.com/squeaks2569 26. Saint Lawrence River, 600 miles. Begins in New York, ends in Canada. demerzel21, Getty Images/iStockphoto 25. Ouachita River, 605 miles. Begins in Arkansas, ends in the Black River in Louisiana. flickr.com/PaddyMurphy 24. Milk River, 625 miles. Begins in Montana, ends in the Missouri River. David P. Lewis, Getty Images/iStockphoto 23. North Platte River, 665 miles. Begins in Colorado, ends at the Platte River in Nebraska.

marekuliasz, Getty Images/iStockphoto 22. Yellowstone River, 678 miles. Begins in Wyoming, ends in the Missouri River in North Dakota. Terribil-T, Getty Images/iStockphoto 21. Cumberland River, 696 miles. Begins in Kentucky, winds through Tennessee before ending in the Ohio River. SeanPavonePhoto, Getty Images/iStockphoto 20. Cimarron River, 698 miles. Begins in Oklahoma and ends in the Arkansas River. Robert_Ford, Getty Images/iStockphoto 19. Kuskokwim River, 702 miles. Begins in Alaska and ends in the Bering Sea. Marc Lester, AP 18. James River (Dakotas), 710 miles. Begins in North Dakota and ends in the Missouri River in South Dakota. flickr.com/jimmywayne 17. White River (Arkansas), 720 miles. Begins in Arkansas and ends in the Mississippi River. Kaye Kerr, Getty Images/iStockphoto 16. Pecos River, 730 miles.

Begins in New Mexico and ends in the Rio Grande in Texas. tonda, Getty Images/iStockphoto 15. Green River, 760 miles. Begins in Wyoming and ends in the Colorado River in Utah. Sam Camp, Getty Images/iStockphoto 14. Brazos River, 860 miles. Begins in Texas and ends at the Gulf of Mexico. CEHBauer, Getty Images 13. Canadian River, 906 miles. Begins in Colorado, ends in the Arkansas River in Oklahoma. flickr.com/TomSpinker 12. Tennessee River, 935 miles. Begins in Tennessee, ends in the Ohio River in Kentucky. SeanPavonePhoto, Getty Images/iStockphoto 11. Colorado River of Texas, 970 miles. Begins in Texas, ends in the Gulf of Mexico. folkinsg, Getty Images/iStockphoto 10. Ohio River, 979 miles. Begins in Pennsylvania, ends in the Mississippi River in Illinois. Henryk Sadura, Getty Images/iStockphoto 9. Snake River, 1040 miles.

Begins in Wyoming, ends in the Columbia River in Washington. AndrewSoundarajan, Getty Images/iStockphoto 8. Red River, 1125 miles. Begins in Oklahoma, ends in the Mississippi River in Louisiana. McFarlandPhoto, Getty Images/iStockphoto 7. Columbia River, 1243 miles. Begins in Canada, ends in the Pacific Ocean in Washington. JPLDesigns, Getty Images/iStockphoto 6. Arkansas River, 1443 miles. Begins in Colorado, ends in the Mississippi River in Arkansas. EntropyWorkshop, Getty Images/iStockphoto 5. Colorado River, 1450 miles. Begins in Colorado, ends in the Gulf of California in Mexico. Wirepec, Getty Images/iStockphoto 4. Rio Grande River, 1759 miles. Begins in Colorado, ends in the Gulf of Mexico in Texas. RangerR, Getty Images/iStockphoto 3. Yukon River, 1979 miles. Begins in Canada, ends in the Bering Sea in Alaska. Pi-Lens, Getty Images/iStockphoto 2.

Mississippi River, 2202 miles. Begins in Minnesota, ends in the Gulf of Mexico in Louisiana. 7Michael, Getty Images/iStockphoto 1. Missouri River, 2341 miles. Begins in Montana, ends at the Mississippi River in Missouri. dina2001, Getty Images/iStockphoto Like this topic? You may also like these photo galleries: Replay What Is The Longest River In North America What Is The Longest River In North America What Is The Longest River In North America North America is blessed with many big rivers and this would explain why the lands around these rivers are so fertile. However, many people want to know what is the longest river in North America? If you do not know the name of the longest river in North America, then read on. The Missouri River is the longest river in North America. The Missouri is a tributary of the Mississippi River, which used to be the longest but not any more. The Missouri River begins its journey from the point where Madison, Jefferson and Gallatin Rivers meet in Montana and it flows south into the Mississippi River. The Missouri is 2,540 miles (4,090 kilometers) long.

Missouri River is known to be full of fish, especially catfish. Some varieties of catfish found in the river are harvested for commercial purposes. Once upon a time, in the 19th and 20th centuries, the upper reaches of the river were famous for its shellfish. However, the population has now diminished and commercial harvesting of shellfish is no longer carried out. The wetland near the delta is the largest in entire United States and is considered to be an important locale for many migratory birds. Just where the Missouri River, the longest river in North America, meets the Mississippi River, the volume of water increases twofold and this is attributed to the Missouri. According to scientists and experts, the Missouri is instrumental in increasing the water volume of the Mississippi by 45 percent under normal circumstances and by 70 percent in droughts. The combining of Missouri and Mississippi gives North America the fourth largest river in the world. More Articles : What is the Longest River in North America What is the Longest River in North America 17 Oct, 2012 what is 0 North America is the third largest continent by area and fourth largest by population.

There are 23 countries found on the continent, but the majority of the continent is made up of Canada and the United States. The continent is bordered by the Arctic Ocean, Atlantic Ocean and the Pacific Ocean and is found to the north-west of South America. North America has many mountain ranges where many rivers begin their journey to lower ground. The longest river on the continent begins in the famous Rocky Mountains. What is the longest river in North America? The title of the longest river in North America is the subject of much debate. In terms of length by main stem, the Missouri River is the longest on the continent. It flows for approximately 3,767 km (2,341 mi) from the Rocky Mountains in western Montana to Missouri where it meets the Mississippi River to the north of St. Louis. Although it is the longest river in North America, it is only the ninth largest in terms of water discharged in the United States. The largest river in this category is the Mississippi, which has an average discharge of over 16,000 cubic meters per second. (almost 600,000 cubic feet per second).

The second longest river by main stem is the Mississippi river at 3,544 km (2,202 mi). These rivers together are called the Mississippi-Missouri River which, if classified as a single river, is the fourth longest in the world. Did you know? There are three streams in the Rocky mountains of Montana and Wyoming that come together to form the Missouri river. The longest of these begins on the slope of Mount Jefferson at about 2,800 m (9,100 ft) above sea level. The drainage for the Missouri river covers 1,300,000 km2, which is more than half a million square miles. This includes parts of two Canadian provinces and 10 U.S. states! Related Articles The Missouri is America’s Longest River The Missouri is America’s Longest River December 18, 2012 Many dams help control the flow of the Missouri River. This one is in Montana. Share Email to a Friend Print Read, listen and learn English with this story. Double-click on any word to find the definition in the Merriam-Webster Learner's Dictionary. This is Shirley Griffith.

And this is Steve Ember with the VOA Special English program, EXPLORATIONS. Today, we tell about another important American river, the Missouri. It is the longest river in the United States. The first American Indians to live along the Missouri River called the river the Mine Sose. It means the muddy river. Even today, the Missouri is called "the Big Muddy" by many people. This is because it carries huge amounts of dirt from the land through which it flows. The dirt makes the river a brown color for much of its length. The Missouri begins in the Rocky Mountains of North America. It is formed by three rivers that come together in what is the north central state of Montana. The three rivers are the Jefferson, Madison, and Gallatin Rivers. They become the Missouri River in the southwestern part of Montana, more than one thousand two hundred meters above sea level. The river is clear and flows rapidly as it begins its travels east and south. It moves more slowly as it flows down to the waters of the Mississippi River, about ten kilometers north of the modern-day city of Saint Louis. The Missouri travels four-thousand kilometers from the high mountains in the north to the low lands of the south.

It flows along the borders of seven states: Montana, North Dakota, South Dakota, Iowa, Nebraska, Kansas, and finally Missouri. The first Europeans who reported seeing the river were at the mouth of the Missouri where it empties into the Mississippi. They were French explorers Jacques Marquette and Louis Jolliet. In Sixteen-Seventy-Three, they were traveling down the Mississippi in a small wooden boat when they heard a great noise of water moving at great speed. Father Marquette wrote that he felt great fear. He saw large trees floating into the Mississippi River. They were carried in violently moving muddy water. The muddy water was the Missouri River which emptied into the western side of the Mississippi. The Missouri was a violent river, making travel along it difficult. Yet explorers and settlers used it as a way to move west. In the early Seventeen-hundreds, French fur traders began to travel along the Missouri to the lands of the great American west. The first non-natives to explore the river, from its mouth to its beginnings, did so in Eighteen-Oh-Five and Eighteen-Oh-Six. President Thomas Jefferson sent Meriwether Lewis and William Clark to explore the area.

The United States government had bought from France a large area of land called the Louisiana Territory. This land extended from the Gulf of Mexico northwest to the Pacific coast. The story of Lewis and Clark's travels up the Missouri River and on to the Pacific Northwest is one of the great stories of American exploration. President Jefferson sent the two men to explore the little-known river to learn all about the land on both sides of it. Lewis and Clark completed the trip in two years. The explorers were the first Americans to cross the Missouri lands to the Pacific Northwest. Lewis and Clark brought back to Washington a detailed report about the plants, trees, animals, climate they found on their travels. Many different scientists have long studied these facts. The two men also returned with a lot of information about the different Indian nations of the West. Since then, the Indian names have become well known through the many stories and books written about them. The Mandans, the Nez Perce, the Sioux, the Blackfeet, the Chickasaws, the Pawnees and the Crows were some of these nations. Most of the Indians Lewis and Clark met along the way were a great help to them. One of the most famous was a woman named Sacagawea.

She was a Shoshone Indian who had been captured by the Mandan tribe. The two explorers knew that the Shoshone Indians who lived near the Rocky Mountains had good horses. Since the two explorers began their trip, they had been traveling up the Missouri River by boat. They knew that they would need horses to help them in the next part of their exploration over land. So, Lewis and Clark took Sacagawea with them. She could help them deal with the Shoshone tribe when they left the river and crossed over the tall, rough mountains. Today, the image of Sacagawea is on the American dollar coin. It honors her part in helping Lewis and Clark explore what became the western United States. Soon after Lewis and Clark explored the territory, settlers began moving west along the Missouri River. They began their western travels on boats that took them from Saint Louis to either Kansas City or Saint Joseph in western Missouri. Then they took wagons to Oregon and California on the coast of the Pacific Ocean. It was the Missouri River that started them on their way to new homes in new lands. A large part of the river became the border between two kinds of land, and two ways of life.

On the east side were beautiful woodlands and lakes. On the west side were great open plains, stretching all the way to the high western Rocky Mountains. The two sides of the river were different when the first European explorers traveled the Missouri. On the east side of the river, the explorers found Indian woodsmen living in tents hidden among trees. These tribes hunted deer. They fought their enemies by surprise attacks from hidden places. On the west side of the river, the explorers found strong Indian buffalo hunters and fighters on horses. These Indians attacked out in the open and wanted no cover to protect themselves only the backs of racing horses. There are similar differences today. On the eastern side of the Missouri are farms and tall corn. On the western side are horses and cows and cowboys. It is said that you need to look in the middle of the Missouri River to find where the American West begins. The state of Missouri is in the center of the United States. It is named after the great river that flows from west to east through its center. The city of Independence is in the western part of the state. It is considered the geographical center of the continental United States.

One of the city's most famous citizens was Harry Truman, who was the Thirty-Third President of the United States. He was president from Nineteen Forty-Five until Nineteen-Fifty-Three. When he left office, Truman returned to his home in Independence, on the shores of the Missouri River. For many years after Lewis and Clark's exploration, only fur traders used the river to carry the goods they wanted to sell. They carried their furs in small boats that were light on the water and did not hit the bottom. Beginning in eighteen thirty, the American Fur Company began to use steam boats to carry goods up and down the Missouri. This trade began to disappear in eighteen fifty-nine. It was then that a railroad was completed between Hannibal, on the Mississippi River in the east, and Saint Joseph, on the Missouri River in the western part of the state of Missouri. It was easier to move goods and people by train. After World War Two ended, the United States government approved a major plan to develop the areas along the Missouri River. The plan included flood control and development along the river. Now a series of six huge dams in the middle area of the river control the flow of the Missouri.

More than one-hundred smaller dams are on smaller rivers that flow into the Missouri. The dams contain the water from the melting snows in the north. They reduce the flooding that once happened down river almost every spring. Today, boats continue to carry goods and people up and down the Missouri River as they have for centuries. Mississippi River | river, United States | Britannica.com Mississippi River New Orleans Mississippi River, the longest river of North America , draining with its major tributaries an area of approximately 1.2 million square miles (3.1 million square km), or about one-eighth of the entire continent . The Mississippi River lies entirely within the United States . Rising in Lake Itasca in Minnesota , it flows almost due south across the continental interior, collecting the waters of its major tributaries, the Missouri River (to the west) and the Ohio River (to the east), approximately halfway along its journey to the Gulf of Mexico through a vast delta southeast of New Orleans , a total distance of 2,340 miles (3,766 km) from its source. With its tributaries, the Mississippi drains all or part of 31 U.S. states and two provinces in Canada .

Lake Itasca, Itasca State Park, northwestern Minnesota. Cbkarim Although the Mississippi can be ranked as the fourth longest river in the world by adding the length of the Missouri- Jefferson (Red Rock) system to the Mississippi downstream of the Missouri-Mississippi confluence—for a combined length of 3,710 miles (5,971 km)—the 2,340-mile length of the Mississippi proper is comfortably exceeded by 19 other rivers. In volume of discharge, however, the Mississippi’s rate of roughly 600,000 cubic feet (17,000 cubic metres) per second is the largest in North America and the eighth greatest in the world. As the central river artery of a highly industrialized nation, the Mississippi River has become one of the busiest commercial waterways in the world, and, as the unruly neighbour of some of the continent’s richest farmland, it has been subjected to a remarkable degree of human control and modification. Furthermore, the river’s unique contribution to the history and literature of the United States has woven it like a bright thread through the folklore and national consciousness of North America, linking the names of two U.S.

presidents— Abraham Lincoln and Ulysses S. Grant —with that of the celebrated author Mark Twain . The Mississippi River basin and its drainage network. Encyclopædia Britannica, Inc. Chicago River On the basis of physical characteristics, the Mississippi River can be divided into four distinct reaches, or sections. In its headwaters, from the source to the head of navigation at St. Paul , Minnesota, the Mississippi is a clear, fresh stream winding its unassuming way through low countryside dotted with lakes and marshes. The upper Mississippi reach extends from St. Paul to the mouth of the Missouri River near St. Louis , Missouri . Flowing past steep limestone bluffs and receiving water from tributaries in Minnesota, Wisconsin , Illinois , and Iowa , the river in this segment assumes the character that led Algonquian-speaking Indians to name it the “Father of Waters” (literally misi, “big”; sipi, “water”). Below the Missouri River junction, the middle Mississippi follows a 200-mile (320-km) course to the mouth of the Ohio River .

The turbulent, cloudy-to-muddy, and flotsam-laden Missouri, especially when in flood, adds impetus as well as enormous quantities of silt to the clearer Mississippi. Beyond the confluence with the Ohio at Cairo , Illinois, the lower Mississippi attains its full grandeur. Where these two mighty rivers meet, the Ohio is actually the larger; thus, below the Ohio confluence the Mississippi swells to more than twice the size it is above. Often 1.5 miles (2.4 km) from bank to bank, the lower Mississippi becomes a brown, lazy river, descending with deceptive quiet toward the Gulf of Mexico. Minneapolis, Minnesota, U.S., on the Mississippi River. © Comstock Images/Jupiterimages The Mississippi River at McGregor, Iowa, U.S. © Davie Muench/Corbis Confluence of the Mississippi (left) and Ohio rivers at Cairo, Illinois. © Alex S. MacLean/Landslides Gateway Arch and downtown St. Louis, Missouri, U.S., on the Misssissippi River. © Digital Vision/Getty Images Memphis, Tennessee, U.S., on the Mississippi River.

© Henryk Sadura/Fotolia USA Facts To geographers, the lower Mississippi has long been a classic example of a meandering alluvial river; that is, the channel loops and curls extravagantly along its floodplain, leaving behind meander scars, cutoffs, oxbow lakes, and swampy backwaters. More poetically, Twain compared its shape to “a long, pliant apple-paring.” Today the sunlight glittering on the twisted ribbon of water remains one of the most distinctive landmarks of a transcontinental flight. Now curbed largely by an elaborate system of embankments (levees), dams, and spillways, this lower section of the Mississippi was the golden, sometimes treacherous, highway for the renowned Mississippi steamboats, those “palaces on paddle wheels” that so fired the public imagination. Physical features Cheetahs Face Extinction Risk Physiography The geology and physical geography of the Mississippi drainage area are essentially those of the Interior Lowlands and Great Plains of North America. Fringes also touch upon the Rocky and Appalachian mountain systems and upon the rim of the Canadian (Laurentian) Shield to the north.

The focus of the system, the floodplain of the lower Mississippi, is of particular interest in that the geology and physical geography of the region are of the river’s own making. Like a huge funnel, the river has taken sediment and debris from contributory areas near the lip of the funnel and deposited much of the product in the alluvial plain of the funnel’s spout, illustrating the interdependence of the entire Mississippi system. Railroad bridge spanning the Big Black River near Vicksburg, Mississippi. Jet Lowe/Historic American Engineering Record/Library of Congress, Washington, D.C. (Digital file no. HAER: MISS,75-BOVI.V,1-6) A grain barge traveling on the Mississippi River along Missouri’s border. Kevin Horan—Stone/Getty Images A barge traveling down the Mississippi River in Louisiana. Thinkstock/Juipterimages The most significant contributory area in recent times has been to the west of the river. Rising in western uplands , notably in the foothills of the Rockies, rivers such as the Red , Arkansas , Kansas , Platte , and Missouri remove considerable silt loads from the rolling expanses of the Great Plains.

These tributaries meander and braid across a wide, gently sloping mantle of unconsolidated materials, laid down over rock beds of the Cretaceous Period (i.e., about 100 million years old), toward the “Father of Waters.” Precipitation in these western areas is light to moderate, usually less than 25 inches (635 mm) per year, but, because at least 70 percent of this precipitation falls as rain between April and September, the erosive capability of the rivers is enhanced (runoff from winter snowmelt is more gradual than from rainstorms). The sandy sediments, moreover, offer little resistance to erosion, so that many of these rivers are only braided in their courses. Connect with Britannica Facebook Twitter YouTube Instagram Pinterest The Mississippi’s eastern contributory rivers drain the well-watered Appalachian Mountain system. Most of this group, including the Kentucky , Green , Cumberland , and Tennessee rivers, flows via well-defined valleys into the Ohio and thence into the Mississippi. The erosive capacity of these rivers varies in relation to the geologic structure of their basins.

These consist of harder rocks in the higher elevations and a softer sill of limestone of the Late Carboniferous Period (i.e., about 300 million years of age), lying below the 1,000-foot (300-metre) elevation line between the Ohio and Tennessee rivers and in the glaciated area of the Ohio’s right-bank tributaries. The third contributory area of the Mississippi also differs from the other two. The upper Mississippi gathers its strength in a region marked by glacial action. After the great ice sheets of the Wisconsin Glacial Stage had put down layers of debris across much of Minnesota, Wisconsin, northern Illinois, and northern Iowa, huge quantities of meltwater flowed south, washing channels through this debris. Today the upper Mississippi and its tributaries, the Wisconsin , St. Croix , Rock , and Illinois rivers, all trace the lines of these former sluiceways. Pouring southward, the glacial meltwaters were joined by the proto-Missouri and Ohio rivers. The combined waters then enlarged the great north-south trough along which the lower Mississippi now flows.

Some 1,000 miles (1,600 km) long, this trough is 25 to 200 miles (40 to 320 km) wide and bounded by escarpments rising up to 200 feet (60 metres) above the valley floor. Geologic studies have revealed that the floor of the glacial trough was later buried by a deep layer of material washed out from an ice sheet and dumped to a thickness of 100 to 300 feet (30 to 90 metres) in the central section. Britannica Lists & Quizzes Editor Picks: Exploring 10 Types of Basketball Movies The Mississippi’s delta is an even more striking monument to the river’s constructive work. There, at the tip of the drainage funnel, millions of years of sedimentation have spilled out across the floor of the Gulf of Mexico , forming cones of sediment that total 300 mi in radius and 30,000 square miles (77,700 square km) in area.

The surface expression of the many sub-deltas is the Mississippi delta, with an area exceeding 11,000 square miles (28,500 square km). Stretching its distributaries into the gulf , the Mississippi once delivered some 220 million tons of sediment there each year, most of it as silt . Today, however, much of this silt is captured behind upstream dams , causing the delta to erode and shrink in area. Compounding this problem are the many hundreds of miles of levees (walls that limit flooding) along the river’s banks, which trap silt in the channel proper. This is especially damaging in the delta, where annual silt additions from flooding help to keep it from being eroded by waves. Climate During winter, mean monthly temperatures in the Mississippi basin range from 55 °F (13 °C) in subtropical southern Louisiana to 10 °F (−12 °C) in subarctic northern Minnesota. Mean monthly temperatures in summer range from 82 °F (28 °C) in Louisiana to 70 °F (21 °C) in Minnesota.

Precipitation sources are low-level moisture from the Gulf of Mexico and some low-level and high-level moisture from the Pacific Ocean . Winter and spring precipitation occurs in the vicinity of easterly and southerly fronts and storms. Average monthly precipitation in winter ranges from 5 inches (130 mm) or more in the south to more than 3 inches (75 mm) over much of the Ohio River basin to less than 1 inch (25 mm) over the western and northern Great Plains. Summer and early autumn rainfall occurs mostly as showers and isolated thunderstorms and weaker frontal storms. Average monthly rainfall ranges from six inches in southern Louisiana and over the mountains of Tennessee and North Carolina to only two or three inches over the Great Plains. Trending Topics Srinivasa Ramanujan The climate is humid over the eastern half of the basin, with large quantities of winter and spring runoff generated over the Tennessee, Ohio, and southern Mississippi river basins. A north-south band of subhumid climates, neither fully humid nor semiarid, extends from central Texas northward to eastern North Dakota .

To the west are the semiarid climates of the Great Plains, and along the Rocky Mountain crests an alpine climate prevails, in which winter snowfalls are released as spring and early summer meltwater runoff. Hydrology It is not surprising that the hydrology of so powerful a river as the Mississippi has been the subject of intense study. In the 19th century Mark Twain described with considerable wit how the pilots of the Mississippi paddle wheelers banded together to run a common information service about changing conditions along the channel. Today the Mississippi River Commission is responsible for river work and considers it worthwhile to maintain a working scale model of the river so that its engineers can test new plans in miniature before embarking on expensive, full-scale projects. Indeed, by the 1920s it was generally believed that enough was known about the river’s hydrology and enough control structures had been built to have tamed the river. Then in 1927 came the most disastrous flood in the recorded history of the lower Mississippi valley . More than 23,000 square miles (59,600 square km) of land flooded. Communications, including roads and rail and telephone services, were cut in many places.

Farms, factories, and whole towns went temporarily underwater. An immense amount of property was damaged, and at least 250 people lost their lives. The river engineers took another look at the hydrology of the Mississippi. Since the freak conditions of 1927, the mean discharge of water into the lower Mississippi by its major tributaries has been carefully monitored. The mean discharge of the main river at Vicksburg , Mississippi , is calculated at 570,000 cubic feet (16,140 cubic metres) per second. About 135 miles (215 km) downriver from Vicksburg, approximately 25 percent of the sediment and water discharge of the river is diverted into the Atchafalaya River through the Old River Complex (Old River Control Structures). These statistics, however, conceal all-important variations in river flow linked with the fluctuating state of the Mississippi’s larger tributaries. Broadly speaking, the western tributaries have the most-irregular flow regimes. They reach a spring or early summer peak that is up to three or four times as great as their winter contribution.

The upper Mississippi and its tributaries reach their maximum flow about the same time (March–June), when melting snows are followed by early summer rains. The winter runoff from this area, however, is also substantial. The crest of the Ohio ’s flow occurs slightly earlier. At Metropolis, Illinois, just above the confluence with the Mississippi, the greatest monthly discharge is usually recorded in March, at which time the Ohio may be providing more than three-fifths of the water being monitored past Vicksburg in the lower river. Thus, the Ohio is chiefly responsible for the lower Mississippi flood situations, which may be aggravated by such factors as early rains in the Great Plains , a sudden hot spell in early spring that melts the northern snows, and heavy downpours throughout the lower valley. Under such conditions the lower river will rise over its banks and put pressure against its man-made levees. Tributaries will back up and form lakes on the far side of these same levees. The current, which normally runs no more than 2 to 3.5 knots (2.5 to 4 miles [4 to 6.5 km] per hour), may then double at constricted points along the main channel.

Thus, for example, the monitoring station at Vicksburg , which at low water in 1936 recorded as little as 93,800 cubic feet (2,660 cubic metres) per second, measured 2,060,000 cubic feet (58,330 cubic metres) per second at high-water stage the following year. In late spring and early summer of 1993 another inevitable yet inconceivably large flood occurred on the Mississippi, this time confined to the parts of the river above its confluence with the Ohio (which was not in flood). Among the worst-hit rivers were the lower reaches of the Missouri, the Des Moines and Raccoon rivers in Iowa, and the Mississippi between the Wisconsin-Illinois border and Cape Girardeau , Missouri. The floods were set off by persistent rains in this region. For the first time in recorded history the Mississippi and the Missouri flooded at the same time—despite the 29 dams on the Mississippi and the 36 giant reservoirs on their tributaries.

The Raccoon River in Des Moines crested at 7 feet (2.1 metres) above the previous high, which constituted a 500-year flood event (a flood so large that it occurs, statistically, only about once every 500 years; or that it has a one in five hundred chance of happening in any year). In many parts of Iowa crops never got planted. In all, some 15 million acres (6.1 million hectares) flooded, and 40 federal levees and 1,043 nonfederal levees broke. This disastrous flood taught many that flood-control structures such as levees, floodwalls, and dams work for some events but fail to provide enough protection from the 100-year (or larger) floods. The floods of 1993 taught many that tight and total control of rivers as large as the Mississippi is neither possible nor economically feasible . Since then, it has become clear that “living with the river” means moving homes, farmhouses, and even entire towns off the floodplains and allowing these lowland areas to flood naturally.

A variety of pollutants , derived from municipal, industrial, and agricultural sources, have been identified in the waters and sediments of the Mississippi River. Organic compounds and trace metals occur in relatively low concentrations; in addition to those naturally present in the water, they derive from industrial and municipal wastes and runoff from agricultural and urban areas. High concentrations of bacteria associated with human waste, however, have been found downstream from some cities and have been attributed to inadequately treated sewage flowing into the river; concentrations downstream from New Orleans , for example, have been found to be many times greater than concentrations above the city. Pollutants have had little widespread effect on the composition of benthic invertebrate populations, which are indicative of changes in water quality. Water samples taken at New Orleans have shown a relatively high dissolved-oxygen content and low biochemical oxygen demand. Thus, by this index, river pollution may be said to be low. Plant and animal life Although the natural vegetation of the Mississippi’s immediate valley is the product of climate and soil rather than of the river, the Mississippi’s swamps and backwaters are ecologically noteworthy.

Threaded along the river, from the wild-rice marshes of Minnesota to the coastal wetlands of the delta, are pockets of thriving plant-animal associations. There the abundance of natural cover, the comparative isolation, and the food provided by such plants as sedges, pondweeds , and millets encourage regular colonization by waterfowl . The path of these birds, as they move up and down the river with the seasons, has been called the Mississippi Flyway, an appropriate name for the vast aerial highway that reaches from the delta to the distant summer nesting grounds in northern Canada. An estimated eight million ducks, geese, and swans winter in the lower part of the flyway, and many more birds use it en route to Latin America . Typical flyway migrants are Canada geese and lesser snow geese, large numbers of mallard and teal, black ducks, widgeon, pintail and ring-necked ducks, and coots. The Mississippi flyway (left) is the most heavily traveled of the migratory routes for birds. In … Encyclopædia Britannica, Inc.

The most important varieties of fish found in the river include several types of catfish (some of which grow to considerable size and are fished commercially by local concerns along the middle and lower river); walleyes and suckers, which thrive in the upper river and provide the basis for a sport-fishing industry in Minnesota and Wisconsin; carp; and garfish. Alligators are now rare, found only in the most isolated backwaters, and the shrimp and crab fisheries of the brackish waters are in decline. Workers preparing to harvest farm-raised catfish in Mississippi. Aquaculture was increasingly … Ken Hammond/USDA Giles Timothy Severin Robert A. Muller Richard H. Kesel Randall J. Schaetzl The Editors of Encyclopædia Britannica Cultural life From Mark Twain ’s evocative description of the antebellum steamboat era in Life on the Mississippi (1883), which he based on his own experiences as a steamboat pilot, to the nostalgic lyrics of Oscar Hammerstein II ’s song “Ol’ Man River” (1927), there is a tremendously rich body of literature and music both about the Mississippi and created by people who have lived along the river.

Literary life on the Mississippi No artist is more indelibly connected with the river than Twain (born Samuel Clemens), whose nom de plume was derived from a riverman’s phrase for water found to be two fathoms (12 feet, or 3.7 metres) deep (see Researcher’s Note: Origins of the name Mark Twain ). Twain grew up on the river in Hannibal , Missouri, and the Mississippi is virtually a character in his classic novels The Adventures of Tom Sawyer (1876) and The Adventures of Huckleberry Finn (1884). Mark Twain. National Academic Quiz Tournaments, LLC School You Gotta Know These North American Rivers The Mississippi River is the second-longest in North America behind the Missouri. Referred to by Abraham Lincoln as “the father of waters,” the Mississippi begins at Lake Itasca, Minnesota, and flows 2,340 miles to a vast delta on the Gulf of Mexico, forming portions of ten state borders and the world's third-largest drainage basin. The Mississippi picks up numerous major tributaries including the Illinois, Missouri, Ohio, Arkansas, and Red Rivers and flows past numerous major cities including Minneapolis, St.

Louis, Memphis, and New Orleans. The Colorado River is the most significant river of the southwestern United States. Beginning in Rocky Mountain National Park in Colorado, the Colorado River runs southwest for 1,450 miles to the Gulf of California in northwestern Mexico. The Colorado formed numerous canyons along much of its length, most notably the Grand Canyon in Arizona. The Colorado also has significant dams such as Hoover Dam near Las Vegas (forming Lake Mead) and Glen Canyon Dam in Arizona (forming Lake Powell). The Ohio River flows 981 miles through a significant industrial region of the central United States. Historically seen as the border between the northern and southern United States, the Ohio is formed in downtown Pittsburgh by the confluence of the Allegheny and Monongahela Rivers, flowing past Wheeling, Cincinnati, Louisville, and Evansville, forming borders of five states before emptying into the Mississippi at Cairo, Illinois. Other major tributaries of the Ohio include the Kanawha, Kentucky, Tennessee, Wabash, and Cumberland Rivers. The Columbia River is a vital waterway of the Pacific Northwest. Rising in the Rockies of British Columbia, the Columbia flows through Lake Revelstoke before entering Washington state.

Grand Coulee Dam along the Columbia in Washington forms Lake Roosevelt. When it was completed in 1943, Grand Coulee was the largest hydroelectric plant in the world; it is still America's largest electric power plant. The Columbia receives the Yakima and Snake Rivers before forming much of the Washington-Oregon border, receiving the Willamette River in Portland before emptying into the Pacific where Lewis and Clark sighted the ocean. The St. Lawrence River drains the Great Lakes and serves as a major waterway of eastern Canada. First explored and named by Jacques Cartier in the early 16th century, the St. Lawrence emerges from the northeastern corner of Lake Ontario in the Thousand Islands archipelago, forming the border between Ontario and New York. The St. Lawrence receives the Ottawa and Saguenay Rivers and flows through Montreal and Quebec City. At its mouth, the Gulf of St. Lawrence is one of the world's largest estuaries. The Hudson River has been a historically significant American river since the early 17th century. Named for English explorer Henry Hudson, it flows 315 miles through eastern New York state.

After receiving the Mohawk River, the Hudson flows past New York's capital of Albany and West Point before forming the boundary between Manhattan and New Jersey. The Hudson is also culturally significant as an inspiration for Washington Irving and the Hudson River School of American landscape painters. The Missouri River is North America's longest, at 2,341 miles. The Missouri is formed in western Montana by the confluence of the Jefferson, Madison, and Gallatin Rivers. It flows past Bismarck, North Dakota and Kansas City before emptying into the Mississippi just north of St. Louis. Lewis and Clark used the Missouri as a route for exploration of the Louisiana Purchase. The Missouri is regulated by a number of major dams, including Fort Peck in Montana and Oahe Dam in South Dakota. The Mackenzie River is the longest river of Canada. Flowing 1,080 miles out of the Great Slave Lake, the river flows past Fort Providence and Fort Simpson in Canada's Northwest Territories, emptying into a vast delta on the Beaufort Sea. The Mackenzie is the largest river flowing into the Arctic Ocean from North America. The river was named for Scottish explorer Alexander Mackenzie, who crossed Canada to the Pacific ten years before Lewis and Clark.

The Potomac River is one of America's most historic waterways. Rising at Fairfax Stone in West Virginia, the Potomac runs 405 miles, forming the border between Virginia and Maryland. Washington, D.C. was sited on the Potomac at its confluence with the Anacostia River. George Washington's plantation Mount Vernon was on the Potomac, while Robert E. Lee's two invasions north of the Potomac were major events of the Civil War. The Rio Grande has formed the border between Texas and four Mexican states since 1848. It flows south out of Colorado through New Mexico before reaching the international boundary near El Paso. Texas's Big Bend National Park is named for the sweeping curve the Rio Grande cuts through the Sierra Madre Oriental. After leaving the mountains, the river flows past Laredo and Brownsville before it empties into the Gulf of Mexico. This article was contributed by former NAQT writer Paul Nelson. Longest Rivers in USA Longest Rivers in USA Map of Americas Longest Rivers in USA USA Map locating some of the longest rivers of USA. Missouri, Mississippi, Yukon, Rio Grande, St.

Lawrence, Arkansas, Colorado, Atchafalaya, Ohio, Red, Brazos, Columbia and Snake are the longest rivers in USA. Disclaimer Close Disclaimer : All efforts have been made to make this image accurate. However Compare Infobase Limited,its directors and employees do not own any responsibility for the correctness or authenticity of the same. Longest Rivers in the US America is a land of geographical diversities. The water discharge of Rocky mountains and the Great Lakes flows through the Great Plains of America. The Missouri River, the longest river in North America, rises from the Rocky Mountains of western Montana. The river flows southeast for 2,540 miles before joining the Mississippi River north of St. Louis in Missouri state. Lauded in many literary works, the river Mississippi is the chief river of the largest drainage system in the North American continent. Its headwaters lie in northern Minnesota and the river flows southwards for 2,340 miles to reach the Gulf of Mexico. Native Americans have lived along the Mississippi and Missouri Rivers and its tributaries for centuries. The Yukon River is a major watercourse of northwestern North America. The lower half of this river lies in Alaska.

The Rio Grande in Texas is one of the major rivers in the southwestern US. The Saint Lawrence River is the primary drainage outflow of the Great Lakes Basin. The Arkansas River, Colorado River, Ohio River, Red River, and Columbia River are among the longest rivers in the US.

Question: What is the longest river in North America?
Answer: Missouri River