For over 12,000 years, people have depended on the Missouri River and itstributaries as a source of sustenance and transportation. More than ten major groups ofNative Americans populated the watershed, with most leading a nomadic lifestyle and dependent on enormousbison herds that roamed through theGreat Plains. The first Europeans encountered the river in the late seventeenth century, and the region passed through Spanish and French hands before becoming part of the United States through theLouisiana Purchase.
The Missouri River was one of the main routes for the westward expansion of the United States during the 19th century. The growth of thefur trade in the early 19th century laid much of the groundwork as trappers explored the region and blazed trails.Pioneers headed westen masse beginning in the 1830s, first bycovered wagon, then by the growing numbers ofsteamboats that entered service on the river. Conflict between settlers and Native Americans in the watershed led to some of the most longstanding violence of theAmerican Indian Wars.
During the 20th century, the Missouri River basin was extensively developed for irrigation, flood control, and the generation ofhydroelectric power. Fifteen dams impound themain stem of the river, with hundreds more on tributaries. The Missouri River's reservoirs include the largest, second-largest, and fourth-largest artificial lakes in the United States by surface area:Lake Sakakawea,Lake Oahe, andFort Peck Lake.Meanders have been cut off and the riverchannelized to improve navigation, reducing its length by almost 200 miles (320 km) from pre-development times. Although the lowerMissouri valley is now a populous and highly productive agricultural and industrial region, heavy development has taken its toll on wildlife and fish populations as well as water quality.
TheGallatin River flows out of Gallatin Lake which is also in Yellowstone National Park.
Holter Lake, a reservoir on the upper Missouri River
The Missouri River officially starts at the confluence of the Jefferson and Madison inMissouri Headwaters State Park nearThree Forks, Montana, and is joined by the Gallatin a mile (1.6 km) downstream. It then passes throughCanyon Ferry Lake, a reservoir west of theBig Belt Mountains. Issuing from the mountains nearCascade, the river flows northeast to the city ofGreat Falls, where it drops over theGreat Falls of the Missouri, a series of five substantial waterfalls. It then winds east through a scenic region of canyons and badlands known as the Missouri Breaks, receiving theMarias River from the west then widening into theFort Peck Lake reservoir a few miles above the confluence with theMusselshell River. Farther on, the river passes through theFort Peck Dam, and immediately downstream, theMilk River joins from the north.[17][18]
Flowing eastward through the plains of eastern Montana, the Missouri receives thePoplar River from the north before crossing intoNorth Dakota where theYellowstone River, its greatest tributary by volume, joins from the southwest. At the confluence, the Yellowstone is actually the larger river.[a]The Missouri then meanders east pastWilliston and intoLake Sakakawea, the reservoir formed byGarrison Dam. Below the dam the Missouri receives theKnife River from the west and flows south toBismarck, the capital of North Dakota, where theHeart River joins from the west. It slows into theLake Oahe reservoir just before theCannonball River confluence. While it continues south, eventually reachingOahe Dam inSouth Dakota, theGrand,Moreau andCheyenne Rivers all join the Missouri from the west.[17][18]
The Missouri makes a bend to the southeast as it winds through the Great Plains, receiving theNiobrara River and many smaller tributaries from the southwest. It then proceeds to form the boundary of South Dakota andNebraska and is joined by theJames River from the north. AtSioux City theBig Sioux River comes in from the north, after which the Missouri forms theIowa–Nebraska boundary. It flows south to the city ofOmaha where it receives its longest tributary, thePlatte River, from the west.[21] Downstream, it begins to define the border between the states of Nebraska andMissouri, then flows between the states of Missouri andKansas. The Missouri swings east atKansas City, where theKansas River enters from the west, and so on into north-central Missouri. To the east of Kansas City, the Missouri receives, on the left side, theGrand River. It passes south ofColumbia and receives theOsage andGasconade Rivers from the south downstream ofJefferson City. The river then rounds the northern side ofSt. Louis to join the Mississippi River on the border between Missouri andIllinois.[17][18]
There is only one river with a personality, a sense of humor, and a woman's caprice; a river that goes traveling sidewise, that interferes in politics, rearranges geography, and dabbles in real estate; a river that plays hide and seek with you today and tomorrow follows you around like a pet dog with a dynamite cracker tied to his tail. That river is the Missouri.
The Missouri River'sdrainage basin spans 529,350 square miles (1,371,000 km2),[12]encompassing nearly one-sixth of the area of the United States[23] or just over five percent of the continent of North America.[24] Comparable to the size of the Canadian province ofQuebec, the watershed covers most of the central Great Plains, stretching from the Rocky Mountains in the west to theMississippi River Valley in the east and from the southern extreme of western Canada to the border of theArkansas River watershed. Compared with the Mississippi River above their confluence, the Missouri is twice as long[b]and drains an area three times as large.[c]The Missouri accounts for 45 percent of the annual flow of the Mississippi past St. Louis, and as much as 70 percent in certain droughts.[7][15]
In 1990, the Missouri River watershed was home to about 12 million people.[12][25] This included the entire population of the U.S. state of Nebraska, parts of the U.S. states of Colorado, Iowa, Kansas, Minnesota, Missouri, Montana, North Dakota, South Dakota, and Wyoming, and small southern portions of the Canadian provinces ofAlberta andSaskatchewan.[12] The watershed's largest city isDenver, Colorado, with a population of more than six hundred thousand. Denver is the main city of theFront Range Urban Corridor whose cities had a combined population of over four million in 2005,[26] making it the largest metropolitan area in the Missouri River basin.[25] Other major population centers – mostly in the watershed's southeastern portion – includeOmaha, Nebraska, north of the confluence of the Missouri and Platte Rivers;Kansas City, Missouri –Kansas City, Kansas, at the confluence of the Missouri with the Kansas River; and the St. Louis metropolitan area, south of the Missouri River just below the latter's mouth, on the Mississippi.[18] In contrast, the northwestern part of the watershed is sparsely populated. However, many northwestern cities, such asBillings, Montana, are among the fastest growing in the Missouri basin.[25]
With more than 170,000 square miles (440,000 km2) under the plow, the Missouri River watershed includes roughly one-fourth of all the agricultural land in the United States, providing more than a third of the country's wheat, flax, barley, and oats. However, only 11,000 square miles (28,000 km2) of farmland in the basin is irrigated. A further 281,000 square miles (730,000 km2) of the basin is devoted to the raising of livestock, mainly cattle. Forested areas of the watershed, mostlysecond-growth, total about 43,700 square miles (113,000 km2). Urban areas, on the other hand, comprise less than 13,000 square miles (34,000 km2) of land. Most built-up areas are along the main stem and a few major tributaries, including the Platte and Yellowstone Rivers.[25][27]
The Missouri inNorth Dakota, which was the furthest upstream that French explorers traveled on the river
Elevation in the watershed varies from just over 400 feet (120 m) at the Missouri's mouth[1] to the 14,293-foot (4,357 m) summit ofMount Lincoln in central Colorado.[28][29] The river drops 8,626 feet (2,629 m) from Brower's Spring, the farthest source. Although the plains of the watershed have extremely little local vertical relief, the land rises about 10 feet per mile (1.9 m/km) from east to west. The elevation is less than 500 feet (150 m) at the eastern border of the watershed, but is over 3,000 feet (910 m) above sea level in many places at the base of the Rockies.[18]
The Missouri's drainage basin has highly variable weather and rainfall patterns, Overall, the watershed is defined by acontinental climate with warm, wet summers and harsh, cold winters. Most of the watershed receives an average of 8 to 10 inches (200 to 250 mm) of precipitation each year.[25] However, the westernmost portions of the basin in the Rockies as well as southeastern regions in Missouri may receive as much as 40 inches (1,000 mm).[25] The vast majority of precipitation occurs in summer in most of the lower and middle basin, although the upper basin is known for short-lived but intense summerthunderstorms such as the one which produced the1972 Black Hills flood throughRapid City, South Dakota.[30] Winter temperatures in the northern and western portions of the basin typically drop to −20 °F (−28.9 °C) or lower every winter with extremes as low as −60 °F (−51.1 °C), while summer highs occasionally exceed 100 °F (37.8 °C) in all areas except the higher elevations of Montana, Wyoming and Colorado. Extreme maxima — almost all prior to 1960 — have exceeded 115 °F (46.1 °C) in all US states in the basin.[25][31]
As one of the continent's most significant river systems,[32] the Missouri's drainage basin borders on many other major watersheds of the United States and Canada. TheContinental Divide, running along the spine of the Rocky Mountains, forms most of the western border of the Missouri watershed.[32] TheClark Fork andSnake River, both part of theColumbia River basin, drain the area west of the Rockies in Montana,Idaho and western Wyoming. The Columbia, Missouri andColorado River watersheds meet atThree Waters Mountain in Wyoming'sWind River Range.[33] South of there, the Missouri basin is bordered on the west by the drainage of theGreen River, a tributary of the Colorado, then on the south by the mainstem of the Colorado. Both the Colorado and Columbia Rivers flow to the Pacific Ocean. However, a largeendorheic drainage called theGreat Divide Basin exists between the Missouri and Green watersheds in western Wyoming. This area is sometimes counted as part of the Missouri River watershed, even though its waters do not flow to either side of the Continental Divide.[34]
To the north, the much lowerLaurentian Divide separates the Missouri River watershed from those of theOldman River, a tributary of theSouth Saskatchewan River, as well as theSouris,Sheyenne, and smaller tributaries of theRed River of the North. All of these streams are part of Canada'sNelson River drainage basin, which empties intoHudson Bay. There are also several large endorheic basins between the Missouri and Nelson watersheds in southern Alberta and Saskatchewan.[32] TheMinnesota andDes Moines Rivers, tributaries of the upper Mississippi, drain most of the area bordering the eastern side of the Missouri River basin. Finally, on the south, theOzark Mountains and other low divides through central Missouri, Kansas and Colorado separate the Missouri watershed from those of theWhite River and Arkansas River, also tributaries of the Mississippi River.[32]
Over 95 significant tributaries and hundreds of smaller ones feed the Missouri River, with most of the larger ones coming in as the river draws close to the mouth.[35] Most rivers and streams in the Missouri River basin flow from west to east, following the incline of the Great Plains; however, some eastern tributaries such as the James,Big Sioux andGrand River systems flow from north to south.[25]
The Missouri's largest tributaries by runoff are the Yellowstone in Montana and Wyoming, the Platte in Wyoming, Colorado, and Nebraska, and theKansas–Republican/Smoky Hill and Osage in Kansas and Missouri. Each of these tributaries drains an area greater than 50,000 square miles (130,000 km2) or has an average discharge greater than 5,000 cu ft/s (140 m3/s).[14][36] The Yellowstone River has the highest discharge, even though the Platte is longer and drains a larger area. In fact, the Yellowstone's flow is about 13,800 cu ft/s (390 m3/s)[37] – accounting for sixteen percent of total runoff in the Missouri basin and nearly double that of the Platte.[38] On the other end of the scale is the tinyRoe River in Montana, which at 201 feet (61 m) long is one of the world's shortest rivers.[39]
The table on the right lists the ten longest tributaries of the Missouri, along with their respective catchment areas and flows. Length is measured to the hydrologic source, regardless of naming convention. The main stem of the Kansas River, for example, is 148 miles (238 km) long.[40] However, including the longest headwaters tributaries, the 453-mile (729 km) Republican River and the 156-mile (251 km)Arikaree River, brings the total length to 749 miles (1,205 km).[40] Similar naming issues are encountered with the Platte River, whose longest tributary, theNorth Platte River, is more than twice as long as its mainstream.[40]
The Missouri's headwaters above Three Forks extend much farther upstream than the main stem. Measured to the farthest source at Brower's Spring, the Jefferson River is 298 miles (480 km) long.[25] Thus measured to its highest headwaters, the Missouri River stretches for 2,639 miles (4,247 km). When combined with the lower Mississippi, the Missouri and its headwaters form part of thefourth-longest river system in the world, at 3,745 miles (6,027 km).[10]
Bydischarge, the Missouri is the ninth largest river of the United States, after the Mississippi,St. Lawrence,Ohio, Columbia,Niagara,Yukon,Detroit, andSt. Clair. The latter two, however, are sometimes considered part of a strait betweenLake Huron andLake Erie.[50] Among rivers of North America as a whole, the Missouri is thirteenth largest, after the Mississippi,Mackenzie, St. Lawrence, Ohio, Columbia, Niagara, Yukon, Detroit, St. Clair,Fraser,Slave, andKoksoak.[50][51]
As the Missouri drains a predominantly semi-arid region, its discharge is much lower and more variable than other North American rivers of comparable length. Before the construction of dams, the river flooded twice each year – once in the "April Rise" or "Spring Fresh", with the melting of snow on the plains of the watershed, and in the "June Rise", caused by snowmelt and summer rainstorms in the Rocky Mountains. The latter was far more destructive, with the river increasing to over ten times its normal discharge in some years.[52][53] The Missouri's discharge is affected by over 17,000 reservoirs with an aggregate capacity of some 141 million acre-feet (174 km3).[25] By providing flood control, the reservoirs dramatically reduce peak flows and increase low flows. Evaporation from reservoirs significantly reduces the river's runoff, causing an annual loss of over 3 million acre-feet (3.7 km3) from mainstem reservoirs alone.[25]
TheUnited States Geological Survey operates fifty-onestream gauges along the Missouri River. The river's average discharge at Bismarck, 1,314.5 miles (2,115.5 km) from the mouth, is 21,920 cu ft/s (621 m3/s). This is from a drainage area of 186,400 sq mi (483,000 km2), or 35% of the total river basin.[61] At Kansas City, 366.1 miles (589.2 km) from the mouth, the river's average flow is 55,400 cu ft/s (1,570 m3/s). The river here drains about 484,100 sq mi (1,254,000 km2), representing about 91% of the entire basin.[55]
The lowermost gage with a period of record greater than fifty years is atHermann, Missouri – 97.9 miles (157.6 km) upstream of the mouth of the Missouri – where the average annual flow was 87,520 cu ft/s (2,478 m3/s) from 1897 to 2010. About 522,500 sq mi (1,353,000 km2), or 98.7% of the watershed, lies above Hermann.[7] The highest annual mean was 181,800 cu ft/s (5,150 m3/s) in 1993, and the lowest was 41,690 cu ft/s (1,181 m3/s) in 2006.[7] Extremes of the flow vary even further. The largest discharge ever recorded was over 750,000 cu ft/s (21,000 m3/s) on July 31, 1993, duringa historic flood.[62] The lowest, a mere 602 cu ft/s (17.0 m3/s) – caused by the formation of anice dam – was measured on December 23, 1963.[7]
Highsilt content makes the Missouri River (left) noticeably lighter than theMississippi River (right) at their confluence north ofSt. Louis.
The Rocky Mountains of southwestern Montana at theheadwaters of the Missouri River first rose in theLaramide Orogeny, amountain-building episode that occurred from around 70 to 45 million years ago (the end of theMesozoic through the earlyCenozoic).[63] ThisorogenyupliftedCretaceous rocks along the western side of theWestern Interior Seaway, a vast shallow sea that stretched from the Arctic Ocean to the Gulf of Mexico, and deposited the sediments that now underlie much of the drainage basin of the Missouri River.[64][65][66]This Laramide uplift caused the sea to retreat and laid the framework for a vast drainage system of rivers flowing from the Rocky andAppalachian Mountains, the predecessor of the modern-day Mississippi watershed.[67][68][69] The Laramide Orogeny is essential to modern Missouri Riverhydrology, as snow and ice melt from the Rockies provide the majority of the flow in the Missouri and its tributaries.[70]
The Missouri and many of its tributaries cross the Great Plains, flowing over or cutting into theOgallala Group and older mid-Cenozoic sedimentary rocks. The lowest major Cenozoic unit, theWhite River Formation, was deposited between roughly 35 and 29 million years ago[71][72] and consists ofclaystone,sandstone,limestone, andconglomerate.[72][73] Channel sandstones and finer-grainedoverbank deposits of thefluvial[74]Arikaree Group were deposited between 29 and 19 million years ago.[71] TheMiocene-age Ogallala and the slightly youngerPliocene-age Broadwater Formation deposited atop the Arikaree Group, and are formed from material eroded off of the Rocky Mountains during a time of increased generation of topographic relief;[71][75] these formations stretch from the Rocky Mountains nearly to the Iowa border and give the Great Plains much of their gentle but persistent eastward tilt, and also constitute a major aquifer.[76]
Immediately before theQuaternaryIce Age, the Missouri River was likely split into three segments: an upper portion that drained northwards into Hudson Bay,[77][78]and middle and lower sections that flowed eastward down the regional slope.[79]As the Earth plunged into the Ice Age, apre-Illinoian (or possibly theIllinoian)glaciation diverted the Missouri River southeastward toward its present confluence with the Mississippi and caused it to integrate into a single river system that cuts across the regional slope.[80] In western Montana, the Missouri River is thought to have once flowed north then east around theBear Paw Mountains.Sapphires are found in some spots along the river in western Montana.[81][82] Advances of the continental ice sheets diverted the river and its tributaries, causing them to pool up into large temporary lakes such as Glacial LakesGreat Falls, Musselshell and others. As the lakes rose, the water in them often spilled across adjacent local drainage divides, creating now-abandoned channels andcoulees including theShonkin Sag, 100 miles (160 km) long. When the glaciers retreated, the Missouri flowed in a new course along the south side of the Bearpaws, and the lower part of the Milk River tributary took over the original main channel.[83]
The Missouri's nickname, the "Big Muddy", was inspired by its enormous loads ofsediment or silt – some of the largest of any North American river.[2][84] In its pre-development state, the rivertransported some 175 to 320 million short tons (159 to 290 million metric tons) per year.[85] The construction of dams and levees has drastically reduced this to 20 to 25 million short tons (18 to 23 million metric tons) in the present day.[86] Much of this sediment is derived from the river'sfloodplain, also called the meander belt; every time the river changed course, it would erode tons of soil and rocks from its banks. However, damming and channeling the river has kept it from reaching its natural sediment sources along most of its course. Reservoirs along the Missouri trap roughly 36.4 million short tons (33.0 million metric tons) of sediment each year.[25] Despite this, the river still transports more than half the total silt that empties into the Gulf of Mexico; theMississippi River Delta, formed by sediment deposits at the mouth of the Mississippi, constitutes a majority of sediments carried by the Missouri.[86][87]
Archaeological evidence, especially in Missouri, suggests that human beings first inhabited the watershed of the Missouri River between 10,000 and 12,000 years ago at the end of thePleistocene.[88] During the end of thelast glacial period, large migration of humans were taking place, such as those via theBering land bridge between the Americas and Eurasia. Over centuries, the Missouri River formed one of these main migration paths. Most migratory groups that passed through the area eventually settled in theOhio Valley and the lower Mississippi River Valley, but many, including theMound builders, stayed along the Missouri, becoming the ancestors of the later Indigenous peoples of the Great Plains.[89]
Indigenous peoples of North America who have lived along the Missouri have historically had access to ample food, water, and shelter. Many migratory animals naturally inhabit the plains area. Before they were hunted by colonists and Native Americans, these animals, such as thebuffalo, provided meat, clothing, and other everyday items; there were also greatriparian areas in the river's floodplain that provided habitat for herbs and other staple foods.[90] No written records from the tribes and peoples of the pre-European contact period exist because they did not yet use writing. According to the writings of early colonists, some of the major tribes along the Missouri River included theOtoe,Missouria,Omaha,Ponca,Dakota,Lakota,Arikara,Hidatsa,Mandan,Assiniboine,Gros Ventres andBlackfeet.[91]
In this pre-colonial and early-colonial era, the Missouri river was used as a path of trade and transport, and the river and its tributaries often formed territorial boundaries. Most of the Indigenous peoples in the region at that time had semi-nomadic cultures, with many tribes maintaining different summer and winter camps. However, the center of Native American wealth and trade lay along the Missouri River in the Dakotas region on its great bend south.[92] A large cluster of walled Mandan, Hidatsa and Arikara villages situated on bluffs and islands of the river was home to thousands, and later served as a market and trading post used by early French and British explorers and fur traders.[93] Following the introduction of horses to Missouri River tribes, possibly from feral European-introduced populations, Natives' way of life changed dramatically. The use of the horse allowed them to travel greater distances, and thus facilitated hunting, communications, warfare, the Siouxoan genocide and expulsion of many tribes, and the abundance of trade.[94]
Once, tens of millions ofAmerican bison (commonly called buffalo), one of thekeystone species of the Great Plains and the Ohio Valley, roamed the plains of the Missouri River basin.[95] Most Native American nations in the basin relied heavily on the bison as a food source, and their hides and bones served to create other household items. In time, the species came to benefit from the indigenous peoples' periodic controlled burnings of the grasslands surrounding the Missouri to clear out old and dead growth. The large bison population of the region gave rise to the termgreat bison belt, an area of rich annual grasslands that extended fromAlaska to Mexico along the eastern flank of the Continental Divide.[96] However, after the arrival of Europeans in North America, both the bison and the Native Americans saw a rapid decline in population.[97] Massive over-hunting for sport by colonists eliminated bison populations east of the Mississippi River by 1833 and reduced the numbers in the Missouri basin to a mere few hundred. Foreign diseases brought by settlers, such assmallpox, raged across the land, decimating Native American populations. Left without their primary source of sustenance, many of the remaining indigenous people were forced onto resettlement areas and reservations, often at gunpoint.[98]
In May 1673, the French-Canadian explorerLouis Jolliet and the French explorerJacques Marquette left the settlement ofSt. Ignace on Lake Huron and traveled down theWisconsin and Mississippi Rivers, aiming to reach the Pacific Ocean. In late June, Jolliet and Marquette became the first documented European discoverers of the Missouri River, which according to their journals was in full flood.[99] "I never saw anything more terrific," Jolliet wrote, "a tangle of entire trees from the mouth of the Pekistanoui [Missouri] with such impetuosity that one could not attempt to cross it without great danger. The commotion was such that the water was made muddy by it and could not clear itself."[100][101] They recordedPekitanoui orPekistanoui as the local name for the Missouri. However, the party never explored the Missouri beyond its mouth, nor did they linger in the area. In addition, they later learned that the Mississippi drained into the Gulf of Mexico and not the Pacific as they had originally presumed; the expedition turned back about 440 miles (710 km) short of the Gulf at the confluence of the Arkansas River with the Mississippi.[100]
In 1682, France expanded its territorial claims in North America to include land on the western side of the Mississippi River, which included the lower portion of the Missouri. However, the Missouri itself remained formally unexplored untilÉtienne de Veniard, Sieur de Bourgmont commanded an expedition in 1714 that reached at least as far as the mouth of the Platte River. It is unclear exactly how far Bourgmont traveled beyond there; he described the blond-hairedMandans in his journals, so it is likely he reached as far as their villages in present-day North Dakota.[102] Later that year, Bourgmont publishedThe Route To Be Taken To Ascend The Missouri River, the first known document to use the name "Missouri River"; many of the names he gave to tributaries, mostly from the native tribes that lived along them, are still in use today. The expedition's discoveries eventually found their way to cartographerGuillaume Delisle, who used the information to create a map of the lower Missouri.[103] In 1718,Jean-Baptiste Le Moyne, Sieur de Bienville requested that the French government bestow upon Bourgmont theCross of St. Louis because of his "outstanding service to France".[103]
Bourgmont had in fact been in trouble with the French colonial authorities since 1706, when he deserted his post as commandant ofFort Detroit after poorly handling anattack by theOttawa that resulted in thirty-one deaths.[104] However, his reputation was enhanced in 1720 when thePawnee – who had earlier been befriended by Bourgmont – massacred the SpanishVillasur expedition near present-dayColumbus, Nebraska, on the Missouri River, temporarily ending Spanish encroachment on French Louisiana.[105]
Bourgmont establishedFort Orleans, the first European settlement of any kind on the Missouri River, near present-dayBrunswick, Missouri, in 1723. The following year Bourgmont led an expedition to enlistComanche support against the Spanish, who continued to show interest in taking over the Missouri. In 1725 Bourgmont brought the chiefs of several Missouri River tribes to visit France. There he was raised to the rank of nobility and did not accompany the chiefs back to North America. Fort Orleans was either abandoned or its small contingent massacred by Native Americans in 1726.[103][106]
TheFrench and Indian War erupted when territorial disputes between France and Great Britain in North America reached a head in 1754. By 1763, France's army in North America had been defeated by a combined British-American force and was forced to sue for peace. In theTreaty of Paris, France ceded its Canadian possessions to the British, gaining Louisiana from theSpanish in return.[107]Initially, the Spanish did not extensively explore the Missouri and let French traders continue their activities under license. However, this ended after news of incursions by trappers working for theHudson's Bay Company in the upper Missouri River watershed was brought back following an expedition by Jacques D'Eglise in the early 1790s.[108] In 1795 the Spanish chartered the Company of Discoverers and Explorers of the Missouri, popularly referred to as the "Missouri Company", and offered a reward for the first person to reach the Pacific Ocean via the Missouri. In 1794 and 1795 expeditions led byJean-Baptiste Truteau and Antoine Simon Lecuyer de la Jonchšre did not even make it as far north as the Mandan villages in central North Dakota.[109]
Arguably the most successful of the Missouri Company expeditions was that of James MacKay andJohn Evans.[110] The two set out along the Missouri, and established Fort Charles about 20 miles (32 km) south of present-day Sioux City as a winter camp in 1795. At the Mandan villages in North Dakota, they forcefully expelled several British traders, and while talking to the populace they pinpointed the location of the Yellowstone River, which was calledRoche Jaune ("Yellow Rock") by the French. Although MacKay and Evans failed to accomplish their original goal of reaching the Pacific, they did create the first accurate map of the upper Missouri River.[109][111]
In 1795, the young United States and Spain signedPinckney's Treaty, which recognized American rights to navigate the Mississippi River and store goods for export in New Orleans.[112] Three years later, Spain revoked the treaty and in 1800 secretly returned Louisiana toNapoleonic France in theThird Treaty of San Ildefonso. This transfer was so secret that the Spanish continued to administer the territory. In 1801, Spain restored rights to use the Mississippi and New Orleans to the United States.[113]
Fearing that the cutoffs could occur again, PresidentThomas Jefferson proposed to buy the port of New Orleans from France for $10 million. Instead, faced with a debt crisis, Napoleon offered to sell the entirety of Louisiana, including the Missouri River, for $15 million – amounting to less than 3¢ per acre. The deal was signed in 1803, doubling the size of the United States with the acquisition of theLouisiana Territory.[114]In 1803, Jefferson instructedMeriwether Lewis to explore the Missouri and search for a water route to the Pacific Ocean. By then, it had been discovered that theColumbia River system, which drains into the Pacific, had a similar latitude as the headwaters of the Missouri River, and it was widely believed that a connection or short portage existed between the two.[115] However, Spain balked at the takeover, citing that they had never formally returned Louisiana to the French. Spanish authorities warned Lewis not to take the journey and forbade him from seeing the MacKay and Evans map of the Missouri, although Lewis eventually managed to gain access to it.[116][117]
Meriwether Lewis andWilliam Clark begantheir famed expedition in 1804 with a party of thirty-three people in three boats.[118] Although they became the first Europeans to travel the entire length of the Missouri and reach the Pacific Ocean via the Columbia, they found no trace of the Northwest Passage. The maps made by Lewis and Clark, especially those of thePacific Northwest region, provided a foundation for future explorers and emigrants. They also negotiated relations with numerous Native American tribes and wrote extensive reports on the climate, ecology and geology of the region. Many present-day names of geographic features in the upper Missouri basin originated from their expedition.[119]
As early as the 18th century, fur trappers entered the extreme northern basin of the Missouri River in the hopes of finding populations ofbeaver andriver otter, the sale of whose pelts drove the thrivingNorth American fur trade. They came from many different places – some from the Canadian fur corporations at Hudson Bay, some from the Pacific Northwest (see also:Maritime fur trade), and some from the midwestern United States. Most did not stay in the area for long, as they failed to find significant resources.[120]
The first glowing reports of country rich with thousands of game animals came in 1806 when Meriwether Lewis and William Clark returned from their two-year expedition. Their journals described lands amply stocked with thousands of buffalo, beaver, and river otter; and also an abundant population ofsea otters on the Pacific Northwest coast. In 1807, explorerManuel Lisa organized an expedition which would lead to the explosive growth of the fur trade in the upper Missouri River country. Lisa and his crew traveled up the Missouri and Yellowstone Rivers, trading manufactured items in return for furs from local Native American tribes, and established a fort at the confluence of the Yellowstone and a tributary, theBighorn, in southern Montana. Although the business started small, it quickly grew into a thriving trade.[121][122]
Lisa's men started construction ofFort Raymond, which sat on a bluff overlooking the confluence of the Yellowstone and Bighorn, in the fall of 1807. The fort would serve primarily as a trading post for bartering with the Native Americans for furs.[123] This method was unlike that of the Pacific Northwest fur trade, which involved trappers hired by the various fur enterprises, namelyHudson's Bay. Fort Raymond was later replaced byFort Lisa at the confluence of the Missouri and Yellowstone in North Dakota; a second fort also calledFort Lisa was built downstream on the Missouri River in Nebraska. In 1809 theSt. Louis Missouri Fur Company was founded by Lisa in conjunction with William Clark and Pierre Choteau, among others.[124][125] In 1828, theAmerican Fur Company foundedFort Union at the confluence of the Missouri and Yellowstone Rivers. Fort Union gradually became the main headquarters for the fur trade in the upper Missouri basin.[126]
Fur trapping activities in the early 19th century encompassed nearly all of the Rocky Mountains on both the eastern and western slopes. Trappers of the Hudson's Bay Company, St. Louis Missouri Fur Company, American Fur Company,Rocky Mountain Fur Company,North West Company and other outfits worked thousands of streams in the Missouri watershed as well as the neighboring Columbia, Colorado, Arkansas, and Saskatchewan river systems. During this period, the trappers, also calledmountain men, blazed trails through the wilderness that would later form the paths pioneers and settlers would travel by into the West. Transport of the thousands of beaver pelts required ships, providing one of the first large motives for river transport on the Missouri to start.[127]
As the 1830s drew to a close, the fur industry slowly began to die as silk replaced beaver fur as a desirable clothing item. By this time, also, the beaver population of streams in the Rocky Mountains had been decimated by intense hunting. Furthermore, frequent Native American attacks on trading posts made it dangerous for employees of the fur companies. In some regions, the industry continued well into the 1840s, but in others such as the Platte River valley, declines of the beaver population contributed to an earlier demise.[128] The fur trade finally disappeared in the Great Plains around 1850, with the primary center of industry shifting to the Mississippi Valley and central Canada. Despite the demise of the once-prosperous trade, however, its legacy led to the opening of the American West and a flood of settlers, farmers, ranchers, adventurers, hopefuls, financially bereft, and entrepreneurs took their place.[129]
The river roughly defined theAmerican frontier in the 19th century, particularly downstream from Kansas City, where it takes a sharp eastern turn into the heart of the state of Missouri, an area known as theBoonslick. As first area settled by Europeans along the river it was largely populated by slave-owning southerners following theBoone's Lick Road. The major trails for the opening of the American West all have their starting points on the river, including theCalifornia,Mormon,Oregon, andSanta Fe trails. The first westward leg of thePony Express was a ferry across the Missouri atSt. Joseph, Missouri. Similarly, most emigrants arrived at the eastern terminus of theFirst transcontinental railroad via a ferry ride across the Missouri betweenCouncil Bluffs, Iowa, and Omaha.[130][131] TheHannibal Bridge became the first bridge to cross the Missouri River in 1869, and its location was a major reason why Kansas City became the largest city on the river upstream from its mouth at St. Louis.[132]
True to the then-ideal ofManifest Destiny, over 500,000 people set out from the river town ofIndependence, Missouri, to their various destinations in the American West from the 1830s to the 1860s. These people had many reasons to embark on this strenuous year-long journey – economic crisis, and later gold strikes including theCalifornia Gold Rush, for example.[133] For most, the route took them up the Missouri to Omaha, Nebraska, where they wouldset out along the Platte River, which flows from the Rocky Mountains in Wyoming and Colorado eastward through the Great Plains. An early expedition led byRobert Stuart from 1812 to 1813 proved the Platte impossible to navigate by thedugout canoes they used, let alone the large sidewheelers and sternwheelers that would later ply the Missouri in increasing numbers. One explorer remarked that the Platte was "too thick to drink, too thin to plow".[134] Nevertheless, the Platte provided an abundant and reliable source of water for the pioneers as they headed west. Covered wagons, popularly referred to asprairie schooners, provided the primary means of transport until the beginning of regular boat service on the river in the 1850s.[135]
During the 1860s, gold strikes in Montana, Colorado, Wyoming, and northernUtah attracted another wave of hopefuls to the region. Although some freight was hauled overland, most transport to and from the gold fields was done through the Missouri and Kansas Rivers, as well as theSnake River in western Wyoming and theBear River in Utah, Idaho, and Wyoming.[136] It is estimated that of the passengers and freight hauled from the Midwest to Montana, over 80 percent were transported by boat, a journey that took 150 days in the upstream direction. A route more directly west into Colorado lay along the Kansas River and its tributary the Republican River as well as pair of smaller Colorado streams,Big Sandy Creek and theSouth Platte River, to near Denver. The gold rushes precipitated the decline of theBozeman Trail as a popular emigration route, as it passed through land held by often-hostile Native Americans. Safer paths were blazed to theGreat Salt Lake nearCorinne, Utah, during the gold rush period, which led to the large-scale settlement of the Rocky Mountains region and easternGreat Basin.[137]
Karl Bodmer,Fort Pierre and the Adjacent Prairie, c. 1833, – the river, river bluffs and floodplain are depicted around the fort settlement
As settlers expanded their holdings into the Great Plains, they ran into land conflicts with Native American tribes. This resulted in frequent raids, massacres and armed conflicts, leading to the federal government creating multiple treaties with the Plains tribes, which generally involved establishing borders and reserving lands for the indigenous. As with many other treaties between the U.S. and Native Americans, they were soon broken, leading to huge wars. Over 1,000 battles, big and small, were fought between the U.S. military and Native Americans before the tribes were forced out of their land onto reservations.[138][139]
Conflicts between natives and settlers over the opening of the Bozeman Trail in the Dakotas, Wyoming and Montana led toRed Cloud's War, in which theLakota andCheyenne fought against the U.S. Army. The fighting resulted in a complete Native American victory.[140] In 1868, theTreaty of Fort Laramie was signed, which "guaranteed" the use of theBlack Hills,Powder River Country and other regions surrounding the northern Missouri River to Native Americans without white intervention.[141] The Missouri River was also a significant landmark as it divides northeastern Kansas from western Missouri; pro-slavery forces from Missouri would cross the river into Kansas and spark mayhem duringBleeding Kansas, leading to continued tension and hostility even today betweenKansas and Missouri. Another significant military engagement on the Missouri River during this period was the1861 Battle of Boonville, which did not affect Native Americans but rather was a turning point in theAmerican Civil War that allowed theUnion to seize control of transport on the river, discouraging the state of Missouri from joining theConfederacy.[142]
However, the peace and freedom of the Native Americans did not last for long. TheGreat Sioux War of 1876–77 was sparked when American miners discovered gold in the Black Hills of western South Dakota and eastern Wyoming. These lands were originally set aside for Native American use by the Treaty of Fort Laramie.[141] When the settlers intruded onto the lands, they were attacked by Native Americans. U.S. troops were sent to the area to protect the miners, and drive out the natives from the new settlements. During this bloody period, both the Native Americans and the U.S. military won victories in major battles, resulting in the loss of nearly a thousand lives. The war eventually ended in an American victory, and the Black Hills were opened to settlement. Native Americans of that region were relocated to reservations in Wyoming and southeastern Montana.[143]
In the late 19th and early 20th centuries, a great number of dams were built along the course of the Missouri, transforming 35 percent of the river into a chain of reservoirs.[12] River development was stimulated by a variety of factors, first by growing demand for electricity in the rural northwestern parts of the basin, and by floods and droughts that plagued rapidly growing agricultural and urban areas along the lower Missouri River.[144] Small, privately owned hydroelectric projects have existed since the 1890s, but the large flood-control and storage dams that characterize the middle reaches of the river today were not constructed until the 1950s.[25][144]
Between 1890 and 1940, five dams were built in the vicinity ofGreat Falls to generate power from theGreat Falls of the Missouri, a chain of giant waterfalls formed by the river in its path through western Montana.Black Eagle Dam, built in 1891 onBlack Eagle Falls, was the first dam of the Missouri.[145] Replaced in 1926 with a more modern structure, the dam was little more than a small weir atop Black Eagle Falls, diverting part of the Missouri's flow into the Black Eagle power plant.[146] The largest of the five dams,Ryan Dam, was built in 1913. The dam lies directly above the 87-foot (27 m)Big Falls, the largest waterfall of the Missouri.[147]
Black Eagle Dam is dynamited in 1908 to save Great Falls from the flood wave caused by the failure of Hauser Dam
In the same period, several private establishments – most notably theMontana Power Company – began to develop the Missouri River above Great Falls and belowHelena for power generation. A smallrun-of-the river structure completed in 1898 near the present site ofCanyon Ferry Dam became the second dam built on the Missouri. This rock-filledtimber crib dam generated seven and a halfmegawatts of electricity for Helena and the surrounding countryside.[148] The nearbysteelHauser Dam was finished in 1907, but failed in 1908 because of structural deficiencies, causing catastrophic flooding all the way downstream pastCraig. At Great Falls, a section of the Black Eagle Dam was dynamited to save nearby factories from inundation.[149] Hauser was rebuilt in 1910 as a concrete gravity structure, and stands to this day.[150][151]
Holter Dam, about 45 miles (72 km) downstream of Helena, was the third hydroelectric dam built on this stretch of the Missouri River.[152] When completed in 1918 by the Montana Power Company and the United Missouri River Power Company, its reservoir flooded theGates of the Mountains, a limestone canyon which Meriwether Lewis described as "the most remarkable clifts that we have yet seen ... the tow[er]ing and projecting rocks in many places seem ready to tumble on us."[153] In 1949, theU.S. Bureau of Reclamation (USBR) began construction on the modern Canyon Ferry Dam to provide flood control to the Great Falls area. By 1954, the rising waters ofCanyon Ferry Lake submerged the old 1898 dam, whose powerhouse still stands underwater about1+1⁄2 miles (2.4 km) upstream of the present-day dam.[154]
[ The Missouri's temperament was as ] "uncertain as the actions of a jury or the state of a woman's mind".
The Missouri basin suffered a series of catastrophic floods around the turn of the 20th century, most notably in1844,1881, and1926–1927.[156] In 1940, as part of theGreat Depression-eraNew Deal, theU.S. Army Corps of Engineers (USACE) completed Fort Peck Dam in Montana. Construction of this massive public works project provided jobs for more than 50,000 laborers during the Depression and was a major step in providing flood control to the lower half of the Missouri River.[157] However, Fort Peck only controls runoff from 11 percent of the Missouri River watershed, and had little effect on a severe snowmelt flood that struck the lower basin three years later. This event was particularly destructive as it submerged manufacturing plants in Omaha and Kansas City, greatly delaying shipments of military supplies in World War II.[156][158]
Map showing major features of thePick–Sloan Plan; other dams and their reservoirs are denoted by triangles
Flooding damages on the Mississippi–Missouri river system were one of the primary reasons for whichCongress passed theFlood Control Act of 1944, opening the way for theUSACE to develop the Missouri on a massive scale.[159][160] The 1944 act authorized thePick–Sloan Missouri Basin Program (Pick–Sloan Plan), which was a composite of two widely varying proposals. The Pick plan, with an emphasis on flood control and hydroelectric power, called for the construction of large storage dams along the main stem of the Missouri. The Sloan plan, which stressed the development of local irrigation, included provisions for roughly 85 smaller dams on tributaries.[144][161]
In the early stages of Pick–Sloan development, tentative plans were made to build a low dam on the Missouri at Riverdale, North Dakota, and 27 smaller dams on the Yellowstone River and its tributaries.[162] This was met with controversy from inhabitants of the Yellowstone basin, and eventually theUSBR proposed a solution: to greatly increase the size of the proposed dam at Riverdale – today's Garrison Dam, thus replacing the storage that would have been provided by the Yellowstone dams. Because of this decision, the Yellowstone is now the longest free-flowing river in the contiguous United States.[163] In the 1950s, construction commenced on the five mainstem dams – Garrison, Oahe,Big Bend,Fort Randall, andGavins Point – proposed under the Pick-Sloan Plan.[144] Along with Fort Peck, which was integrated as a unit of the Pick-Sloan Plan in the 1940s, these dams now form the Missouri River Mainstem System.[164]
The flooding of lands along the Missouri River heavily impacted Native American groups whose reservations included fertile bottomlands and floodplains, especially in the arid Dakotas where it was some of the only good farmland they had. These consequences were pronounced in North Dakota'sFort Berthold Indian Reservation, where 150,000 acres (61,000 ha) of land was taken by the construction of Garrison Dam. The Mandan, Hidatsa and Arikara / Sanish tribes sued the federal government on the basis of the1851 Treaty of Fort Laramie which provided that reservation land could not be taken without the consent of both the tribes and Congress. After a lengthy legal battle the tribes were coerced in 1947 to accept a $5.1 million ($55 million today) settlement for the land, just $33 per acre. In 1949 this was increased to $12.6 million. The tribes were even denied the right to use the reservoir shore "for grazing, hunting, fishing, and other purposes".[165][166]
Fort Peck Dam, the uppermost dam of the Missouri River Mainstem System
The six dams of the Mainstem System, chiefly Fort Peck, Garrison, and Oahe, are amongthe largest dams in the world by volume; their sprawling reservoirs also rank amongthe biggest of the nation.[167] Holding up to 74.1 million acre-feet (91.4 km3) in total, the six reservoirs can store more than three years' worth of the river's flow as measured below Gavins Point, the lowermost dam.[25] This capacity makes it the largest reservoir system in the United States and one of the largest in North America.[168] In addition to storing irrigation water, the system also includes an annual flood-control reservation of 16.3 million acre-feet (20.1 km3).[164] Mainstem power plants generate about 9.3 billionKWh annually – equal to a constant output of almost 1,100megawatts.[169] Along with nearly 100 smaller dams on tributaries, namely theBighorn, Platte, Kansas, and Osage Rivers, the system provides irrigation water to nearly 7,500 sq mi (19,000 km2) of land.[144][170]
The table at left lists statistics of all fifteen dams on the Missouri River, ordered downstream.[18] Many of therun-of-the-river power generation dams on the Missouri (marked in yellow) form very small impoundments which may or may not have been given names; those unnamed are left blank. All dams are on the upper half of the river above Sioux City; the lower river is uninterrupted due to its longstanding use as a shipping channel.[181]
[ Missouri River shipping ] "never achieved its expectations. Even under the very best of circumstances, it was never a huge industry".
— Richard Opper, former executive director Missouri River Basin Association[182]
Painting of the steamboatYellowstone, one of the earliest commercial vessels to run on the river, circa 1833. The dangerous currents in the river caused the ship to run aground on asandbar in this illustration.
Boat travel on the Missouri began with the wood-framed canoes andbull boats that Native Americans used for thousands of years before the colonization of the Great Plains introduced larger craft to the river.[183] The first steamboat on the Missouri was theIndependence, which started running between St. Louis andKeytesville, Missouri, around 1819.[184] By the 1830s, large mail and freight-carrying vessels were running regularly between Kansas City and St. Louis, and many traveled even farther upstream. A handful, such as theWestern Engineer and theYellowstone, could make it up the river as far as eastern Montana.[183][185]
During the early 19th century, at the height of the fur trade, steamboats andkeelboats travelled nearly the whole length of the Missouri from Montana's rugged Missouri Breaks to the mouth, carrying beaver and buffalo furs to and from the areas the trappers frequented.[186] This resulted in the development of theMissouri River mackinaw, which specialized in carrying furs. Since these boats could only travel downriver, they were dismantled and sold for lumber upon their arrival at St. Louis.[183]
Water transport increased through the 1850s with multiple craft ferrying pioneers, emigrants and miners; many of these runs were from St. Louis or Independence to near Omaha. There, most of these people would set out overland along the large but shallow and unnavigable Platte River, which pioneers described as "a mile wide and an inch deep" and "the most magnificent and useless of rivers".[187] Steamboat navigation peaked in 1858 with over 130 boats operating full-time on the Missouri, with many more smaller vessels.[188] Many of the earlier vessels were built on the Ohio River before being transferred to the Missouri. Side-wheeler steamboats were preferred over the larger sternwheelers used on the Mississippi and Ohio because of their greater maneuverability.[186]
TheFar West is typical of the shallow-draft steamboats used to navigate the Missouri River. Famed captain and pilotGrant Marsh set several speed records, including one taking wounded soldiers from the surviving segments of Custer'sBlack Hills Expedition to get medical care.[189][190]A barge travels North on the Missouri River at Highway 364 inSaint Charles, Missouri
The industry's success, however, did not guarantee safety. In the early decades before man controlled the river's flow, its sketchy rises and falls and its massive amounts of sediment, which prevented a clear view of the bottom, wrecked some 300 vessels. Because of the dangers of navigating the Missouri River, the average ship's lifespan was only about four years.[188] The development of the Transcontinental andNorthern Pacific Railroads marked the beginning of the end of steamboat commerce on the Missouri. Outcompeted by trains, the number of boats slowly dwindled, until there was almost nothing left by the 1890s. Transport of agricultural and mining products by barge, however, saw a revival in the early twentieth century.[191][192]
Since the beginning of the 20th century, the Missouri River has been extensively engineered for water transport purposes, and about 32 percent of the river now flows through artificially straightened channels.[12] In 1912, the USACE was authorized to maintain the Missouri to a depth of six feet (1.8 meters) from thePort of Kansas City to the mouth, a distance of 368 miles (592 km).[18] This was accomplished by constructing levees andwing dams to direct the river's flow into a straight, narrow channel and prevent sedimentation. In 1925, the USACE began a project to widen the river's navigation channel to 200 feet (61 m); two years later, they began dredging a deep-water channel from Kansas City to Sioux City. These modifications have reduced the river's length from some 2,540 miles (4,090 km) in the late 19th century to 2,341 miles (3,767 km) in the present day.[6][193]
Construction of dams on the Missouri under the Pick-Sloan Plan in the mid-twentieth century was the final step in aiding navigation. The large reservoirs of the Mainstem System help provide a dependable flow to maintain the navigation channel year-round, and are capable of halting most of the river's annual freshets.[194] However, high and low water cycles of the Missouri – notably the protracted early-21st-century drought in the Missouri River basin[195] and historic floods in 1993[196] and 2011[197] – are difficult for even the massive Mainstem System reservoirs to control.[197]
In 1945, the USACE began the Missouri River Bank Stabilization and Navigation Project, which would permanently increase the river's navigation channel to a width of 300 feet (91 m) and a depth of nine feet (2.7 meters). During work that continues to this day, the 735-mile (1,183 km) navigation channel from Sioux City to St. Louis has been controlled by building rock dikes to direct the river's flow and scour out sediments, sealing and cutting off meanders and side channels, and dredging the riverbed.[198] However, the Missouri has often resisted the efforts of the USACE to control its depth. In 2006, theU.S. Coast Guard stated that commercial barge tows ran aground in the Missouri River because the navigation channel had been severely silted.[199] The USACE was blamed for failing to maintain the channel to the minimum depth.[200]
The Missouri River nearNew Haven, Missouri, looking upstream – note theriprapwing dam protruding into the river from the left to direct its flow into a narrower channelThe Missouri River at the confluence with theFloyd River inSioux City, Iowa, near the upper most navigable reach of the river today
In 1929, theMissouri River Navigation Commission estimated the amount of goods shipped on the river annually at 15 million tons (13.6 million metric tons), providing widespread consensus for the creation of a navigation channel. However, shipping traffic has since been far lower than expected – shipments of commodities including produce, manufactured items, lumber, and oil averaged only 683,000 tons (616,000 t) per year from 1994 to 2006.[201]
By tonnage of transported material, Missouri is by far the largest user of the river accounting for 83 percent of river traffic, while Kansas has 12 percent, Nebraska three percent and Iowa two percent. Almost all of the barge traffic on the Missouri River ships sand and gravel dredged from the lower 500 miles (800 km) of the river; the remaining portion of the shipping channel now sees little to no use by commercial vessels.[201]
For navigation purposes, the Missouri River is divided into two main sections. The Upper Missouri River is north ofGavins Point Dam, the last hydroelectric dam offifteen on the river, just upstream fromSioux City, Iowa.[202] The Lower Missouri River is the 840 miles (1,350 km) of river below Gavins Point until it meets the Mississippi just aboveSt. Louis. The Lower Missouri River has nohydroelectric dams orlocks but it has a plethora ofwing dams that enablebarge traffic by directing the flow of the river into a 200-foot-wide (61 m), 12-foot-deep (3.7 m) channel. These wing dams have been put in place by and are maintained by theU.S. Army Corps of Engineers, and there are no plans to construct any locks to replace these wing dams on the Missouri River.
Tonnage of goods shipped by barges on the Missouri River has seen a serious decline from the 1960s to the present. In the 1960s, the USACE predicted an increase to 12 million short tons (11 Mt) per year by 2000, but instead the opposite has happened. The amount of goods plunged from 3.3 million short tons (3.0 Mt) in 1977 to just 1.3 million short tons (1.2 Mt) in 2000.[203] One of the largest drops has been in agricultural products, especially wheat. Part of the reason is that irrigated land along the Missouri has only been developed to a fraction of its potential.[204] In 2006, barges on the Missouri hauled only 200,000 short tons (180,000 t) of products which is equal to thedaily freight traffic on the Mississippi.[204]
Drought conditions in the early 21st century and competition from other modes of transport – mainly railroads – are the primary reason for decreasing river traffic on the Missouri. The USACE's failure to consistently maintain the navigation channel has also hampered the industry. Efforts are being made to revive the shipping industry on the Missouri River, because of the efficiency and cheapness of river transport to haul agricultural products, and the overcrowding of alternative transportation routes. Solutions such as expanding the navigation channel and releasing more water from reservoirs during the peak of the navigation season are under consideration.[205]Drought conditions lifted in 2010, in which about 334,000 short tons (303,000 t) were barged on the Missouri, representing the first significant increase in shipments since 2000. However, flooding in 2011 closed record stretches of the river to boat traffic – "wash[ing] away hopes for a bounce-back year".[206]
There are no lock and dams on the lower Missouri River, but there are plenty ofwing dams thatjettie out into the river and make it harder for barges to navigate. In contrast, the upper Mississippi has29 locks and dams and averaged 61.3 million tons of cargo annually from 2008 to 2011,[207] and its locks are closed in the winter.[208][209]
Historically, the thousands of square miles that comprised the floodplain of the Missouri River supported a wide range of plant and animal species. Biodiversity generally increased proceeding downstream from the cold, subalpine headwaters in Montana to the temperate, moist climate of Missouri. Today, the river'sriparian zone consists primarily ofcottonwoods,willows andsycamores, with several other types of trees such asmaple andash.[210] Average tree height generally increases farther from the riverbanks for a limited distance, as land next to the river is vulnerable to soil erosion during floods. Because of its large sediment concentrations, the Missouri does not support many aquatic invertebrates.[210] However, the basin supports about 300 species of birds[210] and 150 species of fish,[211] some of which areendangered such as thepallid sturgeon. The Missouri's aquatic and riparian habitats also support several species of mammals, such asminks, river otters, beavers,muskrats, andraccoons.[155]
TheWorld Wide Fund For Nature divides the Missouri River watershed into three freshwaterecoregions: the Upper Missouri, Lower Missouri and Central Prairie. The Upper Missouri, roughly encompassing the area within Montana, Wyoming, southern Alberta and Saskatchewan, and North Dakota, comprises mainly semiaridshrub-steppe grasslands with sparse biodiversity because ofIce Ageglaciations. There are no knownendemic species within the region. Except for the headwaters in the Rockies, there is little precipitation in this part of the watershed.[212] The Middle Missouri ecoregion, extending through Colorado, southwestern Minnesota, northern Kansas, Nebraska, and parts of Wyoming and Iowa, has greater rainfall and is characterized by temperate forests and grasslands. Plant life is more diverse in the Middle Missouri, which is also home to about twice as many animal species.[213] Finally, the Central Prairie ecoregion is situated on the lower part of the Missouri, encompassing all or parts of Missouri, Kansas, Oklahoma and Arkansas. Despite large seasonal temperature fluctuations, this region has the greatest diversity of plants and animals of the three. Thirteen species ofcrayfish are endemic to the lower Missouri.[214]
Since river commerce and industrial development began in the 1800s, human activity has severely polluted the Missouri and degraded its water quality. Most of the river's floodplain habitat is long gone, replaced by irrigated agricultural land. Development of the floodplain has led to increasing numbers of people and infrastructure within areas at high risk of inundation. Levees have been constructed along more than a third of the river to keep floodwater within the channel, but with the consequences of faster stream velocity and a resulting increase of peak flows in downstream areas.Fertilizer runoff, which causes elevated levels of nitrogen and other nutrients, is a major problem along the Missouri River, especially in Iowa and Missouri. This form of pollution also affects the upper Mississippi,Illinois and Ohio Rivers. Low oxygen levels in rivers and the vastGulf of Mexico dead zone at the end of the Mississippi Delta are both results of high nutrient concentrations in the Missouri and other tributaries of the Mississippi.[215]
Agricultural fields dominate most of the formerfloodplain, including this area around the Missouri's confluence with theNishnabotna River in western Missouri.
Channelization of the lower Missouri waters has made the river narrower, deeper and less accessible to riparian flora and fauna. Many dams and bank stabilization projects have been built to help convert 300,000 acres (1,200 km2) of Missouri River floodplain to agricultural land. Channel control has reduced the volume of sediment transported downstream by the river and eliminated critical habitat for fish, birds and amphibians.[216] By the early 21st century, declines in populations of native species prompted theU.S. Fish and Wildlife Service to issue a biological opinion recommending restoration of river habitats for federally endangered bird and fish species.[217]
The USACE began work on ecosystem restoration projects along the lower Missouri River in the early 21st century. Because of the low use of the shipping channel in the lower Missouri maintained by the USACE, it is now considered feasible to remove some of the levees, dikes, and wing dams that constrict the river's flow, thus allowing it to naturally restore its banks.[216] By 2001, there were 87,000 acres (350 km2) of riverside floodplain undergoing active restoration.[218]
Restoration projects have re-mobilized some of the sediments that had been trapped behind bank stabilization structures, prompting concerns of exacerbated nutrient and sediment pollution locally and downstream in the northern Gulf of Mexico. A 2010National Research Council report assessed the roles of sediment in the Missouri River, evaluating current habitat restoration strategies and alternative ways to manage sediment.[219] The report found that a better understanding of sediment processes in the Missouri River, including the creation of a "sediment budget" – an accounting of sediment transport, erosion, and deposition volumes for the length of the Missouri River – would provide a foundation for projects to improve water quality standards and protect endangered species.[220]
Part of theMissouri National Recreational River, a 98-mile (158 km) preserved stretch of the Missouri on the border of South Dakota and Nebraska
With over 1,500 sq mi (3,900 km2) of open water, the six reservoirs of the Missouri River Mainstem System provide some of the main recreational areas within the basin. Visitation has increased from 10 million visitor-hours in the mid-1960s to over 60 million visitor-hours in 1990.[204] Development of visitor facilities was spurred by the Federal Water Project Recreation Act of 1965, which required the USACE to build and maintain boat ramps, campgrounds and other public facilities along major reservoirs.[25] Recreational use of Missouri River reservoirs is estimated to contribute $85–100 million to the regional economy each year.[221]
TheLewis and Clark National Historic Trail, some 3,700 miles (6,000 km) long, follows nearly the entire Missouri River from its mouth to its source, retracing the route of the Lewis and Clark Expedition. Extending fromWood River, Illinois, in the east, toAstoria, Oregon, in the west, it also follows portions of the Mississippi and Columbia Rivers. The trail, which spans through eleven U.S. states, is maintained by various federal and state government agencies; it passes through some 100 historic sites, notably archaeological locations including theKnife River Indian Villages National Historic Site.[222][223]
Parts of the river itself are designated for recreational or preservational use. TheMissouri National Recreational River consists of portions of the Missouri downstream from Fort Randall and Gavins Point Dams that total 98 miles (158 km).[224][225] These reaches exhibit islands, meanders, sandbars, underwater rocks,riffles,snags, and other once-common features of the lower river that have now disappeared under reservoirs or have been destroyed by channeling. About forty-five steamboat wrecks are scattered along these reaches of the river.[226][227]
Downstream from Great Falls, Montana, about 149 miles (240 km) of the river course through a rugged series of canyons and badlands known as the Missouri Breaks. This part of the river, designated a U.S.National Wild and Scenic River in 1976, flows within theUpper Missouri Breaks National Monument, a 375,000-acre (1,520 km2) preserve comprising steep cliffs, deep gorges, arid plains, badlands, archaeological sites, and whitewater rapids on the Missouri itself. The preserve includes a wide variety of plant and animal life; recreational activities include boating, rafting, hiking and wildlife observation.[228][229]
In north-central Montana, some 1,100,000 acres (4,500 km2) along over 125 miles (201 km) of the Missouri River, centering onFort Peck Lake, comprise theCharles M. Russell National Wildlife Refuge.[230] The wildlife refuge consists of a native northern Great Plains ecosystem that has not been heavily affected by human development, except for the construction of Fort Peck Dam. Although there are few designated trails, the whole preserve is open to hiking and camping.[231]
^The Missouri's flow atCulbertson, Montana, 25 mi (40 km) above the confluence of the two rivers, is about 9,820 cu ft/s (278 m3/s)[19] and the Yellowstone's discharge atSidney, Montana, roughly the same distance upstream along that river, is about 12,370 cu ft/s (350 m3/s).[20]
^The Mississippi River flows for approximately 1,172 miles (1,886 km) above St. Louis,[18] which is just over half of the Missouri's length.
^The Mississippi drains an area of 172,200 sq mi (446,000 km2) above the confluence with the Missouri River.[14]
^"Long Pool" is the name used by area residents to refer to the smooth, almost lake-like 55 mi (89 km) stretch of the Missouri between the Black Eagle Dam and the town ofCascade. Only about 2 mi (3.2 km) of the so-called Long Pool are actually part of the impoundment behind the dam.
^abHoward Perlman, USGS (October 31, 2012)."Lengths of major rivers".Ga.water.usgs.gov. USGS Water-Science School. Archived fromthe original on March 9, 2014. RetrievedNovember 21, 2012.
^"Missouri River".Columbia Environmental Research Center. U.S. Geological Survey. September 8, 2009.Archived from the original on June 19, 2012. RetrievedMay 10, 2010.
^"North America".Encyclopædia Britannica.Archived from the original on May 20, 2012. RetrievedMay 10, 2010.
^"Missouri River at Great Falls, Montana".River Discharge Database. Madison, WI: Center for Sustainability and the Global Environment (SAGE), Gaylord Nelson Institute for Environmental Studies, University of Wisconsin. Archived fromthe original on September 2, 2006. RetrievedJanuary 19, 2012.
^Nicholls, Elizabeth L.; Russell, Anthony P. (September 18, 1989). Paleobiogeography of the Cretaceous Western Interior Seaway: the vertebrate evidence (Report). Department of Biological Sciences. University of Calgary.
^abLove, J.D.; Christiansen, Ann Coe."White River Formation".Mineral Resources On-Line. Spatial Data. U.S. Geological Survey.Archived from the original on August 8, 2014. RetrievedFebruary 12, 2011.
^Denson, N.M.; Gill, J.R.; Roberts, A.E."White River Formation".Mineral Resources On-Line. Spatial Data. U.S. Geological Survey. Archived fromthe original on March 12, 2012. RetrievedFebruary 12, 2011.
^Martin, J.E.; Sawyer, J.F.; Fahrenbach, M.D.; Tomhave, D.W.; Schulz, L.D."Arikaree Group".Mineral Resources On-Line. Spatial Data. U.S. Geological Survey.Archived from the original on August 8, 2014. RetrievedFebruary 12, 2011.
^"Montana Sapphires".Gem Gallery. Gemology.Archived from the original on October 28, 2011. RetrievedOctober 29, 2011. Note: Includes map of major Montana sapphire mines
^"Missouri River Sediment"(PDF).Missouri River Stream Team Website. Missouri River Recovery Plan Fact Sheet, U.S. Army Corps of Engineers.Archived(PDF) from the original on April 7, 2012. RetrievedOctober 6, 2010.
^"Mandan Indians".Lewis and Clark Interactive Journey Log. National Geographic. Archived fromthe original on February 18, 2011. RetrievedOctober 5, 2010.
^Blackmar, Frank W., ed. (1912). "Bourgmont's Expedition".Kansas.A cyclopedia of state history, embracing events, institutions, industries, counties, cities, towns, prominent persons, etc.
^"The Villasur Expedition–1720".Nebraska State Historical Society. June 4, 2004. Archived from the original on February 10, 2008. RetrievedJanuary 19, 2012.
^Nasatir, Abraham P. (1927). "Jacques d'Eglise on the Upper Missouri, 1791–1795".Mississippi Valley Historical Review. pp. 47–56.
^abWilliams, David (1949). "John Evans' strange journey: Part II. Following the trail".American Historical Review. pp. 508–529.
^"The Mackay and Evans Map".Lewis and Clark in the Illinois Country. Illinois State Museum.Archived from the original on June 24, 2012. RetrievedJanuary 23, 2012.
^"Treaty of San Ildefonso".The Napoleon Series. Government & Politics.Archived from the original on June 8, 2011. RetrievedOctober 4, 2010.
^"Louisiana Purchase".The Lewis and Clark Journey of Discovery. U.S. National Park Service. Archived fromthe original on November 29, 2010. RetrievedOctober 4, 2010.
^"The Mackay and Evans Map".Lewis and Clark in the Illinois Country. The Illinois State Museum.Archived from the original on June 24, 2012. RetrievedJanuary 6, 2011.
^"The Journey Begins".Lewis & Clark Interactive Journey Log. National Geographic. Archived fromthe original on February 17, 2011. RetrievedOctober 5, 2010.
^"Introduction".Lewis and Clark Expedition: A National Register of Historic Places Travel Itinerary. U.S. National Park Service. Archived fromthe original on April 10, 2012. RetrievedOctober 5, 2010.
^"Native Americans".Transcontinental Railroad (film). The American Experience. PBS.Archived from the original on September 6, 2011. RetrievedOctober 5, 2010.
^abcdeReuss, Martin (n.d.).The Pick-Sloan Plan(PDF) (Report). Engineer Pamphlets. U.S. Army Corps of Engineers. Archived fromthe original(PDF) on July 3, 2011. RetrievedOctober 5, 2010. — Extract from a larger document; converted to .pdf August 2002.
^ab"Holter Dam".PPL Montana. Producing Power. Archived fromthe original on July 25, 2010. RetrievedOctober 7, 2010.
^"Gates of the Mountains".Lewis and Clark–A Geologic Perspective. Montana Bureau of Mines and Geology. Archived fromthe original on February 5, 2009. RetrievedJanuary 16, 2012.
^ab"Canyon Ferry Dam". U.S. Bureau of Reclamation. August 10, 2010. Archived fromthe original on September 27, 2012. RetrievedJanuary 7, 2011.
^Flood Control Act of 1944 (Report). Digest of Federal Resource Laws of Interest to the U.S. Fish and Wildlife Service. U.S. Fish and Wildlife Service.Archived from the original on December 3, 2010. RetrievedOctober 5, 2010.
^Missouri River Basin (Report). 78th Congress, 2nd Session. U.S. Congress. November 21, 1944.Report of a Committee of Two Representatives Each from the Corps of Engineers, U.S. Army, and the Bureau of Reclamation, Appointed to Review the Features Presented by the Corps of Engineers (House Document No. 475) and the Bureau of Reclamation (Senate Document No. 191) for the Comprehensive Development of the Missouri River Basin
^Johnston, Paul (2006).History of the Pick-Sloan Program. World Environmental and Water Resource Congress. American Society of Civil Engineers. Archived fromthe original on January 20, 2013. RetrievedJanuary 19, 2012.
^"Toston Dam (Broadwater-Missouri)"(PDF). Water Projects Bureau. Montana Department of Natural Resources and Conservation. Archived fromthe original(PDF) on July 21, 2011. RetrievedMarch 16, 2011.
^"Rainbow Dam".PPL Montana. Producing Power. Archived fromthe original on July 15, 2011. RetrievedMarch 16, 2011.
^"Cochrane Dam".PPL Montana. Producing Power. Archived fromthe original on July 15, 2011. RetrievedMarch 16, 2011.
^"Morony Dam".PPL Montana. Producing Power. Archived fromthe original on July 15, 2011. RetrievedMarch 16, 2011.
^Wilson, Ron (June 2003)."Garrison Dam: A half-century later"(PDF).ND Outdoors. North Dakota Game and Fish Department. p. 14. Archived fromthe original(PDF) on July 21, 2011. RetrievedMarch 16, 2011.
^"Long dry spells cut into Missouri River navigation".News Tribune. May 26, 2010.
^abc"Missouri River Boats"(PDF).State Historical Society of North Dakota. Archived fromthe original(PDF) on August 13, 2011. RetrievedJanuary 28, 2012.
^Carlson, Gayle F.; Bozell, John R.; Pepperi, Robert (2004)."The Search For Engineer Cantonment"(PDF).Explore Nebraska Archaeology. Nebraska State Historical Society. Archived from the original on May 7, 2012. RetrievedJanuary 28, 2012.
^Larson, Lee W."The great USA flood of 1993". Destructive Water: Water-caused natural disasters – their abatement and control (Report). National Oceanic and Atmospheric Administration.Archived from the original on January 26, 2012. RetrievedJanuary 14, 2012.
^"Executive Summary". U.S. Fish and Wildlife Service Biological Opinion on the Operation of the Missouri River Main Stem Reservoir System, Operation and Maintenance of the Missouri River Bank Stabilization and Navigation Project, and Operation of the Kansas River Reservoir System (Report). U.S. Army Corps of Engineers / U.S. Fish and Wildlife Service.Archived from the original on March 21, 2012. RetrievedJanuary 19, 2011.
^"Nature & Science".Niobrara National Scenic River. U.S. National Park Service. May 28, 2009.Archived from the original on August 29, 2010. RetrievedOctober 12, 2010.
^"Big Hidatsa Village Site". National Historic Landmark Summary Listing (Report). U.S. National Park Service. Archived fromthe original on June 6, 2011. RetrievedMarch 16, 2011.
^"Fort Atkinson". Lewis and Clark Expedition. U.S. National Park Service. Archived fromthe original on January 11, 2011. RetrievedMarch 3, 2011.
Houck, Louis (1908).A history of Missouri from the earliest explorations and settlements until the admission of the state into the union. Vol. 1. R.R. Donnelley and Sons, Co.ISBN978-0-405-02856-4.{{cite book}}:ISBN / Date incompatibility (help)
Kellogg, Louis Phelps (1917).Early narratives of the Northwest, 1634–1699. Vol. 18. C. Scribners's Sons.
Singer, Siegfried Fred (1970).Global effects of environmental pollution: a symposium organized by the American Association for the Advancement of Science. Springer.ISBN978-90-277-0151-0.
South Dakota State Historical Society; South Dakota Department of History (1902).South Dakota historical collections. Vol. 1. State Publishing Co.
Committee on Missouri River Recovery and Associated Sediment Management Issues, National Research Council (2010).Missouri River Planning: Recognizing and Incorporating Sediment Management. National Academies Press.Bibcode:2010nap..book13019N.
"Missouri River". USGS Columbia Environmental Research Center.Archived from the original on June 19, 2012. RetrievedOctober 1, 2010.
"Missouri River Dams and Reservoirs".Google Maps. Interactive Maps and Air photos.Archived from the original on November 29, 2018. RetrievedJanuary 19, 2012 – via mappingsupport.com.
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