Skip to main content
Select Source:

Rivers

RIVERS

RIVERS. America's rivers played a vital role in the early exploration, settlement, and development of the country. Long before white settlers arrived on American shores and began following river channels into the country's interior, Native peoples had been canoeing the waterways of the continent. Some of the detailed maps the indigenous cartographers created still exist today.

River Pathways to Exploration

The exploration of America via river travel boasts a history that includes nearly every major waterway. Among the first European explorers was Captain John Smith, who in 1608 traveled the Potomac River, a body of water that traverses nearly 400 miles to form the fourth-largest watershed on the East Coast. Settlers established the colony of Maryland on the lower Potomac less than twenty-five years later, and colonization of the northern Virginia shore followed within a decade.

Commissioned by the Dutch East India Company, Captain Henry Hudson began his exploration of America's northeastern coast in 1609, eventually sailing into the mouth of a river near today's New York City. He hoped the river, now named the Hudson River, would offer a passage west to the Pacific. However, near the location of present-day Albany he found the river too shallow to continue and was forced to turn back.

The early seventeenth century also marked the first time the 1,200-mile-long Columbia River appeared on European maps—after Spanish maritime explorer Martin de Auguilar located it in the Pacific Northwest. That river would eventually become one of the many water highways used by the Lewis and Clark expedition of 1804 to 1806. During that same expedition, Meriwether Lewis and William Clark depended heavily on the Missouri River, using it and its tributaries to transport them from St. Louis to the northern plains and on to Montana.

Without question, the Mississippi River has also played an important role in the European exploration of America. In 1673, Jacques Marquette and Louis Joliet traveled the Upper Mississippi River, descending the Wisconsin River and returning to Lake Michigan via present-day Illinois. Others soon followed, and the Mississippi quickly became a major artery of traffic.

Rivers As Sources for Early Industrial Transport and Power

The mid-1600s began to see rivers as major thoroughfares of transportation for moving both people and products, and there was scarcely a hamlet or a trading post that did not have water connection with the coast. Through the better part of three centuries, such rivers as the Saint Croix, Penobscot, Kennebec, Androscoggin, Saco, and Piscataqua bore millions of logs downstream from the vast forests of Maine until timber resources diminished.

The Merrimack River, until the coming of the railroads, carried a significant portion of New Hampshire's goods, principally timber and granite, to towns below, and especially to its nearest large market, Boston. Parts of New Hampshire and Vermont depended upon the Connecticut River. Northwestern Vermont and northern New York traded with Quebec and Montreal via the Richelieu and Saint Lawrence Rivers.

Rivers also became significant sources of power for sawmills and gristmills. Along the Piscataqua, which stretched from Maine to New Hampshire, a sawmill sprang up as early as 1631 that produced lumber, shingles, and barrel staves. A multitude of other sawmills that depended on river power followed.

Gristmills, or operations for grinding grain, also utilized rivers for generating power, as did rice and textile mills. In the early nineteenth century, the fast-running Willimantic River attracted many cotton manufacturers from Rhode Island and Massachusetts. They situated their water-powered cotton mills in Willimantic, Connecticut, and along the length of the Quinebaug and Shetucket Rivers. The city of Willimantic eventually became a major American center for silk thread and cloth production between the end of the Civil War and the outbreak of World War II.

Rivers As Sources of Transportation

During the eighteenth century, thousands of newcomers traveled up the western tributaries of the Susquehanna and Potomac Rivers, crossed the watershed, and followed the Youghiogheny, Monongahela, Conemaugh, and Allegheny Rivers downward to populate the Ohio Valley. The great Mississippi River system then became the settlers' highway, and their natural markets included the French communities of Saint Louis and New Orleans. Most were in favor of the War of 1812 because a conquest of Canada would add a new commercial outlet to the east through control of the Saint Lawrence River. George Washington and others warned that if better connections were not established with the Ohio Valley residents, their allegiance might follow their trade down the Mississippi to the Spaniards. The Mississippi River system played a significant role until the railroads began cutting across the natural trade routes.

Farther south, emigrants from Virginia and the Carolinas pushed up the James, Dan, Yadkin, and Catawba Rivers, through the mountains, to populate southwestern Virginia and northeastern Tennessee. The men of that region, in signifying their allegiance to the Revolution, spoke of themselves as "Men of the settlements beyond the Alleghenies, where the Watauga and the Holston flow to the Tennessee." Some of the earliest settlers of Nashville left a fort on the Holston River on 22 December 1779 and journeyed down the Holston and the Tennessee in flatboats. They worked up to the mouth of the Cumberland River, and traveled up the Cumberland to the site of Nashville, which they reached on 24 April 1780 after a journey of some 1,300 miles.

Down the lower Atlantic coast were many broad rivers, really estuaries, having tidewater far upstream from their mouths (Patuxent, Chester, Choptank, Nanticoke, Potomac, Rappahannock, York, James, Chowan, Roanoke, Pamlico, Cape Fear, Pee Dee, Santee, Cooper, Saint Johns, and others). These rivers were the chief highways for regular travel as well as for freight transport and saw much traffic in the early days. Great plantations clustered along them, with the mansions fronting the water.

Commercial River Transportation

With the coming of steam technology and before railroads replaced river transport, steamboats began to populate the rivers, particularly in the Midwest and South. Some steamboats traveled where channels were so narrow that they could not turn around except by backing into the mouth of a tributary stream; most could operate only in parts of the winter and spring, when the water was high. Rivers such as the Cumberland, where boats once ran 150 miles or more above Nashville, could pose difficulties for their navigators, and it was said that a town might hear a boat whistle across a bend in the early morning and not see the craft until late afternoon. Mark Twain, enamored with river travel and steamboats, once said a river is a "wonderful book [with] a new story to tell everyday."

In California, when the gold rush began in 1849, the Sacramento and San Joaquin Rivers were almost the only feasible way to travel from San Francisco to the mining regions. There were no steamboats, and many gold-seekers paid high fees for passage upstream in a skiff or yawl, with the understanding that they were to help with the rowing. Others traveled in slow-moving sailing vessels. A steamer built in New York for the Atlantic coast trade went safely around Cape Horn and began operating on the Sacramento River; and until another one followed it four months later, its rates were so high that it earned $20,000 or more on a round trip. After 1855, the Columbia River likewise became the main route to and from the Pacific coast from the mining regions of Idaho and northeastern Washington.

Rivers' Role in Warfare

Rivers have played an important part in the nation's warfare. The French and Indian War took place almost entirely along rivers or intervening lakes. The French came down the Allegheny to seize the forks of the Ohio and build Fort Duquesne. Washington marched by the Potomac, Wills Creek, and the Youghiogheny on his illfated expedition of 1754.

The Ohio River was perhaps the most noted pathway of Indian warfare in American history. For decades, the upper Missouri River saw frequent Indian attacks upon white trappers, traders, and settlers. Much of the fighting of the Revolutionary War in New York State was done on, or immediately near, the Hudson and Mohawk Rivers.

In the Civil War the Potomac, the Rapidan, Rappahannock, North Anna, Chickahominy, and James Rivers served as important strategic barriers in the East, along which armies aligned themselves or fought. The division of Union Gen. George B. McClellan's army by the Chickahominy in the Seven Days' Battles came near being its ruin. The Potomac below Washington, D.C., provided a waterway by which the North could move armies quickly to block the mouth of the James. In the Midwest and South the Mississippi and its tributaries were among the chief objects of strategy. The seizure of the Mississippi in 1863 split the Confederacy in two and presaged its downfall. The Tennessee River furnished the route used by Gen. Ulysses S. Grant's army to reach Chattanooga in the autumn of 1863, and the Battle of Wauhatchie was fought to keep it open. The Red River (southern) witnessed an important but unsuccessful Union expedition in 1864 aimed at Texas.

Decline of River Transportation

In 1862, Congress passed the first of several railroad acts that would eventually connect the continent, lessening the need for rivers as a major mode of transportation within the commercial, public, and military sectors. At the beginning of the twenty-first century, the U.S. Army Corps of Engineers Navigation Data Center reported declining commercial traffic on many of the nation's waterways.

BIBLIOGRAPHY

Adams, Arthur G. The Hudson through the Years. Bronx, N.Y.: Fordham University Press, 1996.

Ambrose, Stephen E. Undaunted Courage: Meriwether Lewis, Thomas Jefferson, and the Opening of the American West. New York: Simon and Schuster, 1996.

Dietrich, William. Northwest Passage: The Great Columbia River. Seattle: University of Washington Press, 1996.

Hahn, Thomas F. Cement Mills along the Potomac River. Morgan-town: West Virginia University Press, 1994.

Merrick, George By Ron. Old Times on the Upper Mississippi: Recollections of a Steamboat Pilot from 1854 to 1863. Minneapolis: University of Minnesota Press, 2001.

Powell, John Wesley, and Anthony Brandt. The Exploration of the Colorado River and Its Canyons. Washington, D.C.: National Geographic Society, 2002.

Reps, John W. Saint Louis Illustrated: Nineteenth-Century Engravings and Lithographs of a Mississippi River Metropolis. Columbia: University of Missouri Press, 1989.

Worster, Donald. A River Running West: The Life of John Wesley Powell. New York: Oxford University Press, 2001.

Alvin F.Harlow

KymO'Connell-Todd

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Rivers." Dictionary of American History. . Encyclopedia.com. 15 Dec. 2017 <http://www.encyclopedia.com>.

"Rivers." Dictionary of American History. . Encyclopedia.com. (December 15, 2017). http://www.encyclopedia.com/history/dictionaries-thesauruses-pictures-and-press-releases/rivers

"Rivers." Dictionary of American History. . Retrieved December 15, 2017 from Encyclopedia.com: http://www.encyclopedia.com/history/dictionaries-thesauruses-pictures-and-press-releases/rivers

Rivers

Rivers

Rivers and streams are bodies of flowing surface water that transport sediment from continental highlands to lakes , alluvial fans, and ultimately the ocean. Streams are the main agent of erosion of the earth's continental crust , and they play a major role in shaping the landscape. Streams are also a focus of humans' interaction with our environment. Human agriculture, industry, and essential biology require fresh, accessible water. Ancient human civilizations first arose in the fertile valleys

of some of the world's greatest rivers: the Yangtze and Yellow Rivers in China, the Tigris and Euphrates Rivers in the Middle East, and the Nile in Egypt. The distribution of the earth's river systems has influenced human population patterns, commerce, and conquest since then, and the availability of uncontaminated surface water for irrigation, industrial and municipal uses remains a pressing geopolitical issue.

Streamflow is a gravity-driven process that acts to level continental topography . Stream erosion balances uplift at plate tectonic boundaries by mechanically and chemically eroding upland rocks, and transporting the resulting siliclastic sediments and dissolved ions and molecules toward the ocean. Current velocity determines a stream's capacity to transport a given volume of suspended and bedload sediment. Sediment transport is intermittent, and individual grains are deposited and re-entrained by turbulent streamflow many times before final deposition in deltas and alluvial fans.

Stream erosion and deposition act in dynamic equilibrium to maintain a concave longitudinal stream profile, called a graded profile, with steep headwaters to low-gradient downstream portions. The elevation where a stream enters another body of water, called base level, controls the downstream end of a stream profile, and the elevation of the headwaters determines the upstream end. Streams cannot erode below base level. Sea level is the ultimate base level for most river systems, and a sea-level change creates a string of compensatory adjustments throughout a stream system. Base level for an individual tributary, however, is controlled by the elevation of the next body of water it enters. If base level falls, or uplift occurs, current velocity increases, and the stream erodes downward. If base level rises, or subsidence occurs, a stream slows down and deposits sediment.

Streams flow in valleys that encompass an area between uplands. Some rivers carve their own valleys, and some flow in preexisting valleys created by other geologic processes like rifting or glacial erosion. The stream channel that contains flow during non-flood times runs through the stream valley flanked by its overspill areas called floodplains . Over time, a stream fills its valley with its own deposits; the stratigraphy of a river basin thus shows the depositional history of the stream. Most streams have a valley, a channel, and a floodplain, but their morphology varies between three end-member typesstraight, meandering, and braideddepending on the stream gradient, the rate of sediment supply, and the sediment grain size.

Straight streams develop in regions where uplift and/or base level fall force rapid regrading by channel incision. Meandering streams develop at the low-gradient, downstream ends of stream profiles. Because they cannot erode below base level, streams near base level maintain their profile by moving horizontally across the stream valley, eroding and depositing sediment with little effect on the overall sediment flux. Meandering streams develop an organized pattern of fluvial landforms and deposits: coarse-grained point bars, gravel channel lags, sandy natural levees, abandoned meanders called oxbow lakes, and fine-grained flood deposits. Braided streams form in mountainous and glaciated areas where rapid currents, voluminous sediment supply, and coarse-grained sediment prevent a stream from forming an orderly pattern of channels and bars. Braided streams have many interlaced channels separated by longitudinal gravel bars that shift over time.

Stream systems are organized into drainage basins with small tributary streams that feed into larger trunk streams, and finally into a major river that lets out into the ocean. Drainage divides are topographic highs that separate drainage basins. Drainage basins and divides vary in scale from small hillside watersheds separated by ridges, to the two halves of the North American continent separated by the continental divide along the spine of the Rocky Mountains. The outcrop pattern of underlying geologic strata determines the geometry of a stream system. Tree-shaped, or dendritic, drainage patterns form when water flows randomly downhill without encountering geologic obstacles or conduits. Dendritic drainages are the most common and form when bedrock layers are horizontal. Trellis-shaped drainages develop in continental fold belts. Rectangular patterns are common in areas of fractured crystalline rocks, and streams flow down the sides of volcanoes in a radial pattern.

See also Alluvial systems; Drainage basins and drainage patterns; Canyon; Estuary; Hydrogeology; Sedimentation; Stream capacity and competence; Stream piracy; Stream valleys, channels, and floodplains

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Rivers." World of Earth Science. . Encyclopedia.com. 15 Dec. 2017 <http://www.encyclopedia.com>.

"Rivers." World of Earth Science. . Encyclopedia.com. (December 15, 2017). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/rivers

"Rivers." World of Earth Science. . Retrieved December 15, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/rivers

rivers

rivers. In the early 21st cent. motorways stride so effortlessly across great rivers that it is easy to overlook the part they have played in British history. We can distinguish a number of different aspects.(a) They were potentially defensible barriers and often formed the boundaries between early kingdoms or later shires. When Ostorius set out to subdue Britain, he conquered, according to Tacitus, the heartland between Severn and Trent. For centuries the Trent and the Humber were the border between north and south England; and the border between England and Scotland, which fluctuated considerably, eventually settled on the Tweed. The Severn, likewise, was at one time the border between England and Wales, until the English pushed it west to the Wye. In the south, the Thames was the effective border between Mercia and Wessex, and neither side found it easy to consolidate gains across the river. Even small rivers were important markers. When Alfred divided the kingdom at Wedmore in 878 with the Danish leader Guthrum, they took the lands east and west of the river Lea. When England was divided up into shires in the 11th cent. rivers were frequently the boundaries—the Tamar, Somerset Avon, Colne, Stour, Ouse, Welland, Dove, Teme, Tyne, Tees, and Mersey.(b) Loops and angles of rivers often provided the opportunity for a defensible settlement. The most spectacular example is perhaps at Durham, where the river Wear curls round the rocky promontory on which castle and cathedral are built. But there are many others. Shrewsbury is on a loop of the Severn; Bristol grew where the Frome joined the Avon, York where the Foss joined the Ouse; Malmesbury where the Tetbury and Sherston branches of the Avon converged.(c) River crossings, by ford or bridge, were of critical importance in both peace and war. They were the natural sites for castles—at Worcester, Oxford, Hereford, Bedford, Cambridge, Carlisle—and the stream of carts and horsemen invited taverns and inns, smiths and stables. Ipswich, Exeter, Gloucester, London, Newcastle all grew up at the first point where the river or estuary could be crossed. Many of the battles in British history were fought at or near river crossings—to prevent escapes, cut off reinforcements, or obstruct junctions. Simon de Montfort was trapped at Evesham in 1265 in the bend of the Avon; Thomas of Lancaster was caught at Boroughbridge in 1322 at the crossing of the Ure; Percy (Hotspur) in 1403, trying to reach his ally Glyndŵr in Wales, found that the king had taken possession of the crossing at Shrewsbury; the English Civil War began in 1642 with a cavalry skirmish at Powicke bridge, south of Worcester, on the river Teme.(d) Rivers facilitated communication and, until the introduction of turnpikes and macadamization in the 18th cent., transport by water was quicker and less fraught than by road or footpath. Towns on estuaries which provided harbours—Plymouth, Hull, Southampton—were particularly well placed, but inland navigation was also important. Few great towns were to be found far from rivers. With the development of river improvements and then canals in the 17th and 18th cents., inland ports—Bewdley, Gainsborough, Rotherham, Reading—flourished. The smallest barge had a capacity vastly greater than the sturdiest packhorse. Even small rivers, if improved, could be turned to good use. Defoe commented in the 1720s that Leominster's prosperity was due to the river Lugg, ‘lately made navigable to the very great profit of the trading part of this country, who have now a very great trade for their corn, wool and other products of this place into the river Wye, and from the Wye into the Severn, and so to Bristol’.(e) The water supply, provided that it was not too contaminated, enabled settlements to grow into thriving towns. There can be little doubt that one reason for the abandonment of Old Sarum in the early 13th cent. for Salisbury was that the old borough on its chalk hill (chosen for its defensive strength) had little water, while the new site to the south was at the confluence of the Avon, Nadder, and Bourne.(f) Rivers became valuable sources of power as soon as water-mills were introduced during the 9th cent. By the time of Domesday there were said to be more than 5,000 mills. In the later Middle Ages, power began to be applied to industry, notably to cloth manufacture, first in fulling, then to other processes. This gave a great advantage to areas with good rivers like west Wiltshire, the Cotswolds, and the Yorkshire dales.

J. A. Cannon

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"rivers." The Oxford Companion to British History. . Encyclopedia.com. 15 Dec. 2017 <http://www.encyclopedia.com>.

"rivers." The Oxford Companion to British History. . Encyclopedia.com. (December 15, 2017). http://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/rivers

"rivers." The Oxford Companion to British History. . Retrieved December 15, 2017 from Encyclopedia.com: http://www.encyclopedia.com/history/encyclopedias-almanacs-transcripts-and-maps/rivers

Runoff

Runoff

Runoff is the component of the hydrologic cycle through which water is returned to the ocean by overland flow. The term runoff is considered synonymous with streamflow and comprises surface runoff resulting from precipitation and that portion of the streamflow that is contributed by groundwater flow entering the stream channel.

Surface runoff consists of that portion of the precipitation reaching the surface that neither infiltrates into the ground nor is retained on the surface. The quantity of surface runoff is controlled by a complex variety of factors. Included among these are precipitation intensity and duration, permeability of the ground surface, vegetation type and density, area of drainage basin, distribution of precipitation, stream-channel geometry, depth to water table , and topographic slope.

In the early stages of a storm, much of the precipitation may be intercepted by vegetation or captured in surface depressions. Water held in this manner often presents a large surface area and is likely to be evaporated. Any water reaching the surface at this stage is more likely to infiltrate before the upper layer of the ground becomes saturated. Thus, storms of light intensity or short duration may produce little or no surface runoff. As storm intensity or duration increases, interception becomes less effective, infiltration capacity of the soil decreases, and surface depressions fill. The result is increasing surface runoff leading to greater flow rates within local stream channels.

Variations in permeability within the soil may cause a portion of the water that infiltrates into the soil to migrate laterally as interflow. Some of the remaining infiltrate will percolate downward to the water table and flow with the groundwater. Ultimately, both of these sources may intercept a stream channel and contribute to the total runoff.

During a particular storm event, the contribution of runoff to a stream varies significantly through time. Inflow to the stream begins with direct channel precipitation followed by overland surface runoff when the appropriate conditions exist. Lateral interflow and groundwater contributions typically move more slowly and impact the stream level later. The groundwater portion of the runoff frequently supports the flow of a stream both during and between storm events.

See also Evaporation

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Runoff." World of Earth Science. . Encyclopedia.com. 15 Dec. 2017 <http://www.encyclopedia.com>.

"Runoff." World of Earth Science. . Encyclopedia.com. (December 15, 2017). http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/runoff

"Runoff." World of Earth Science. . Retrieved December 15, 2017 from Encyclopedia.com: http://www.encyclopedia.com/science/encyclopedias-almanacs-transcripts-and-maps/runoff

Rivers

356. Rivers

See also 234. LAKES ; 360. SEA ; 414. WATER .

alluvion
1. the gradual depositing by a river of earth and other material on the banks.
2. also called alluvium . the material deposited.
fluviation
1. the formation of rivers.
2. a river system.
lutulence
Obsolete, the state or condition of being muddy or turbid. lutulent, adj.
nilometer
an instrument used for measuring the increase in the level of the River Nile during its flood period, consisting of a water chamber containing a graduated pillar. Also niloscope .
potamology
the study of rivers. potamologist, n. potamological, adj.
potamophobia
a morbid fear of rivers.
riparian
a dweller on the bank of a river. riparian, adj.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Rivers." -Ologies and -Isms. . Encyclopedia.com. 15 Dec. 2017 <http://www.encyclopedia.com>.

"Rivers." -Ologies and -Isms. . Encyclopedia.com. (December 15, 2017). http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/rivers

"Rivers." -Ologies and -Isms. . Retrieved December 15, 2017 from Encyclopedia.com: http://www.encyclopedia.com/education/dictionaries-thesauruses-pictures-and-press-releases/rivers

runoff

run·off / ˈrənˌôf/ (also run-off) • n. 1. a further competition, election, race, etc., after a tie or inconclusive result. 2. the draining away of water (or substances carried in it) from the surface of an area of land, a building or structure, etc. ∎  the water or other material that drains freely off the surface of something.

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"runoff." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. 15 Dec. 2017 <http://www.encyclopedia.com>.

"runoff." The Oxford Pocket Dictionary of Current English. . Encyclopedia.com. (December 15, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/runoff

"runoff." The Oxford Pocket Dictionary of Current English. . Retrieved December 15, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/runoff

Rivers

Rivers •has • Sayers •Algiers, cheers, Pamirs, Pears, Piers, Sears, Spears •Teniers •Blackfriars, Briers, pliers •Greyfriars •Bowers, Flowers, ours, Powers, Towers •bejabers • Chambers • Sobers •Scriptures • weight-watchers •glanders, Landers, Randers, sanders •alexanders, Flanders •Enders • Childers • flinders •Saunders • Bermudas • butterfingers •Tigers • Rodgers • starkers •Chequers • Snickers • camiknickers •bonkers • bluchers • Moluccas •Sellers • binoculars • Bahamas •Summers • Marianas • Connors •champers, Pampers •jeepers • jodhpurs • Messrs • Masters •Peters • squitters • Winters •headquarters, hindquarters, Waters •Klosters • Butters •Smithers, withers •Carothers, druthers •Travers • Havers • cleavers • Rivers •vivers • estovers • Marquesas

Cite this article
Pick a style below, and copy the text for your bibliography.

  • MLA
  • Chicago
  • APA

"Rivers." Oxford Dictionary of Rhymes. . Encyclopedia.com. 15 Dec. 2017 <http://www.encyclopedia.com>.

"Rivers." Oxford Dictionary of Rhymes. . Encyclopedia.com. (December 15, 2017). http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rivers

"Rivers." Oxford Dictionary of Rhymes. . Retrieved December 15, 2017 from Encyclopedia.com: http://www.encyclopedia.com/humanities/dictionaries-thesauruses-pictures-and-press-releases/rivers