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141-602: The Manakacha Formation was laid down (especially in the Grand Canyon). It consists of up to 400 feet (120 m) of calcareous sandstone and shaly mudstone. It represents a time when deposition of aeolian sand became more widespread. The Manakacha was deposited at about the same time as the Weber Sandstone was deposited in northeast Utah in Dinosaur National Monument region, northeast of

282-536: A tributary of the Mississippi, the Missouri River is slightly longer and carries a comparable volume of water. When combined with the lower Mississippi River, it forms the world's fourth-longest river system . For over 12,000 years, people have depended on the Missouri River and its tributaries as a source of sustenance and transportation. More than ten major groups of Native Americans populated

423-548: A British army engineer who worked in Egypt prior to World War II . Bagnold investigated the physics of particles moving through the atmosphere and deposited by wind. He recognized two basic dune types, the crescentic dune, which he called " barchan ", and the linear dune, which he called longitudinal or "seif" (Arabic for "sword"). Bagnold developed a classification scheme that included small-scale ripples and sand sheets as well as various types of dunes. Bagnold's classification

564-406: A Y-junction with the fork directed upwind. They have a sharp sinuous or en echelon crest. They are thought to form from a bimodal seasonal wind pattern, with a weak wind season characterized by wind directed an at acute angle to the prevailing winds of the strong wind season. The strong wind season produces a barchan form and the weak wind season stretches this into the linear form. Another possibility

705-413: A boulder or an isolated patch of vegetation. Here the sand builds up to the angle of repose (the maximum stable slope angle), about 34 degrees, then begins sliding down the slip face of the patch. A sandfall is a sand shadow of a cliff or escarpment. Closely related to sand shadows are sand drifts . These form downwind of a gap between obstructions, due to the funneling effect of the obstructions on

846-446: A change in the wind pattern about 3000 years ago. Complex dunes show Little lateral growth but strong vertical growth and are important sand sinks. Vegetated parabolic dunes are crescent-shaped, but the ends of the crescent point upwind, not downwind. They form from the interaction of vegetation patches with active sand sources, such as blowouts. The vegetation stabilizes the arms of the dune, and an elongated lake sometimes forms between

987-688: 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 the Louisiana Territory . In 1803, Jefferson instructed Meriwether Lewis to explore the Missouri and search for a water route to the Pacific Ocean. By then, it had been discovered that

1128-531: A desert. Vegetation is effective at suppressing aeolian transport. Vegetation cover of as little as 15% is sufficient to eliminate most sand transport. The size of shore dunes is limited mostly by the amount of open space between vegetated areas. Aeolian transport from deserts plays an important role in ecosystems globally. For example, wind transports minerals from the Sahara to the Amazon basin . Saharan dust

1269-418: A distinctive crescent shape with the tips of the crescent directed downwind. The dunes are widely separated by areas of bedrock or reg. Barchans migrate up to 30 meters (98 ft) per year, with the taller dunes migrating faster. Barchans first form when some minor topographic feature creates a sand patch. This grows into a sand mound, and the converging streamlines of the air flow around the mound build it into

1410-600: A large endorheic drainage called the Great 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. To the north, the much lower Laurentian Divide separates the Missouri River watershed from those of the Oldman River ,

1551-498: A large aklé or barchanoid dune. They form over a prolonged period of time in areas of abundant sand and show a complex internal structure. Careful 3-D mapping is required to determine the morphology of a draa preserved in the geologic record. Linear dunes can be traced up to tens of kilometers, with heights sometimes in excess of 70 meters (230 ft). They are typically several hundred meters across and are spaced 1 to 2 kilometers (0.62 to 1.24 mi)apart. They sometimes coalesce at

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1692-411: A network of sinuous ridges perpendicular to the wind direction. Aklé dunes are preserved in the geologic record as sandstone with large sets of cross-bedding and many reactivation surfaces. Draas are very large composite transverse dunes. They can be up to 4,000 meters (13,000 ft) across and 400 meters (1,300 ft) high and extend lengthwise for hundreds of kilometers. In form, they resemble

1833-419: A period of record greater than fifty years is at Hermann, 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 m /s) from 1897 to 2010. About 522,500 sq mi (1,353,000 km ), or 98.7% of the watershed, lies above Hermann. The highest annual mean was 181,800 cu ft/s (5,150 m /s) in 1993, and

1974-413: 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. With a drainage basin spanning 529,350 square miles (1,371,000 km ), the Missouri River's catchment encompasses nearly one-sixth of the area of the United States or just over five percent of the continent of North America. Comparable to

2115-405: A sheet-like surface of rock fragments that remains after wind and water have removed the fine particles. The rock mantle in desert pavements protects the underlying material from further deflation. Areas of desert pavement form the regs or stony deserts of the Sahara . These are further divided into rocky areas called hamadas and areas of small rocks and gravel called serirs . Desert pavement

2256-666: A tributary of the South Saskatchewan River , as well as the Souris , Sheyenne , and smaller tributaries of the Red River of the North . All of these streams are part of Canada's Nelson River drainage basin, which empties into Hudson Bay . There are also several large endorheic basins between the Missouri and Nelson watersheds in southern Alberta and Saskatchewan. The Minnesota and Des Moines Rivers, tributaries of

2397-403: A vigorous low-latitude wind system plus more exposed continental shelf due to low sea levels. Wind-deposited sand bodies occur as ripples and other small-scale features, sand sheets , and dunes . Wind blowing on a sand surface ripples the surface into crests and troughs whose long axes are perpendicular to the wind direction. The average length of jumps during saltation corresponds to

2538-419: A whole, the Missouri is thirteenth largest, after the Mississippi, Mackenzie , St. Lawrence, Ohio, Columbia, Niagara, Yukon, Detroit, St. Clair, Fraser , Slave , and Koksoak . 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

2679-535: Is a process of larger grains sliding or rolling across the surface. Saltation refers to particles bouncing across the surface for short distances. Suspended particles are fully entrained in the wind, which carries them for long distances. Saltation likely accounts for 50–70 % of deflation, while suspension accounts for 30–40 % and surface creep accounts for 5–25 %. Regions which experience intense and sustained erosion are called deflation zones. Most aeolian deflation zones are composed of desert pavement ,

2820-576: Is also important in periglacial areas, on river flood plains , and in coastal areas. Coastal winds transport significant amounts of siliciclastic and carbonate sediments inland, while wind storms and dust storms can carry clay and silt particles great distances. Wind transports much of the sediments deposited in deep ocean basins. In ergs (desert sand seas), wind is very effective at transporting grains of sand size and smaller. Particles are transported by winds through suspension, saltation (skipping or bouncing) and creeping (rolling or sliding) along

2961-479: Is also responsible for forming red clay soils in southern Europe. Dust storms are wind storms that have entrained enough dust to reduce visibility to less than 1 kilometer (0.6 mi). Most occur on the synoptic (regional) scale, due to strong winds along weather fronts , or locally from downbursts from thunderstorms. Crops , people, and possibly even climates are affected by dust storms. On Earth, dust can cross entire oceans, as occurs with dust from

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3102-503: Is derived from the name of the Greek god Aeolus , the keeper of the winds. Aeolian processes are those processes of erosion , transport , and deposition of sediments that are caused by wind at or near the surface of the earth. Sediment deposits produced by the action of wind and the sedimentary structures characteristic of these deposits are also described as aeolian . Aeolian processes are most important in areas where there

3243-440: Is downwind movement of particles in a series of jumps or skips. Saltation is most important for grains of up to 2 mm in size. A saltating grain may hit other grains that jump up to continue the saltation. The grain may also hit larger grains (over 2 mm in size) that are too heavy to hop, but that slowly creep forward as they are pushed by saltating grains. Surface creep accounts for as much as 25 percent of grain movement in

3384-552: Is extremely common in desert environments. Blowouts are hollows formed by wind deflation. Blowouts are generally small, but may be up to several kilometers in diameter. The smallest are mere dimples 0.3 meters (1 ft) deep and 3 meters (10 ft) in diameter. The largest include the blowout hollows of Mongolia, which can be 8 kilometers (5 mi) across and 60 to 100 meters (200 to 400 ft) deep. Big Hollow in Wyoming , US, extends 14 by 9.7 kilometers (9 by 6 mi) and

3525-602: Is joined by the Gallatin a mile (1.6 km) downstream. It then passes through Canyon Ferry Lake , a reservoir west of the Big Belt Mountains . Issuing from the mountains near Cascade , the river flows northeast to the city of Great Falls , where it drops over the Great Falls of the Missouri , a series of five substantial waterfalls. It then winds east through a scenic region of canyons and badlands known as

3666-697: Is little or no vegetation. However, aeolian deposits are not restricted to arid climates. They are also seen along shorelines; along stream courses in semiarid climates; in areas of ample sand weathered from weakly cemented sandstone outcrops; and in areas of glacial outwash . Loess , which is silt deposited by wind, is common in humid to subhumid climates. Much of North America and Europe are underlain by sand and loess of Pleistocene age originating from glacial outwash. The lee (downwind) side of river valleys in semiarid regions are often blanketed with sand and sand dunes. Examples in North America include

3807-563: 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. 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). Similar naming issues are encountered with the Platte River, whose longest tributary,

3948-399: Is more important than erosion by wind, but wind erosion is important in semiarid and arid regions. Wind erosion is increased by some human activities, such as the use of 4x4 vehicles . Deflation is the lifting and removal of loose material from the surface by wind turbulence. It takes place by three mechanisms: traction/surface creep, saltation , and suspension. Traction or surface creep

4089-435: Is most applicable in areas devoid of vegetation. In 1941, John Tilton Hack added parabolic dunes, which are strongly influenced by vegetation, to the list of dune types. The discovery of dunes on Mars reinvigorated aeolian process research, which increasingly makes use of computer simulation. Wind-deposited materials hold clues to past as well as to present wind directions and intensities. These features help us understand

4230-575: Is on the Loess Plateau in China . This very same Asian dust is blown for thousands of miles, forming deep beds in places as far away as Hawaii. The Peoria Loess of North America is up to 40 meters (130 ft) thick in parts of western Iowa . The soils developed on loess are generally highly productive for agriculture. Small whirlwinds, called dust devils , are common in arid lands and are thought to be related to very intense local heating of

4371-464: Is sparsely populated. However, many northwestern cities, such as Billings, Montana , are among the fastest growing in the Missouri basin. With more than 170,000 square miles (440,000 km ) 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 km ) of farmland in

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4512-609: Is that these dunes result from secondary flow , though the precise mechanism remains uncertain. Complex dunes (star dunes or rhourd dunes) are characterized by having more than two slip faces. They are typically 500 to 1,000 meters (1,600 to 3,300 ft) across and 50 to 300 meters (160 to 980 ft) high. They consist of a central peak with radiating crests and are thought to form where strong winds can come from any direction. Those in Gran Desierto de Altar of Mexico are thought to have formed from precursor linear dunes due to

4653-463: Is the wearing down by collisions of particles entrained in a moving fluid. It is effective at rounding sand grains and at giving them a distinctive frosted surface texture. Collisions between windborne particles is a major source of dust in the size range of 2-5 microns. Most of this is produced by the removal of a weathered clay coating from the grains. Wind dominates the transport of sand and finer sediments in arid environments. Wind transport

4794-437: Is up to 90 meters (300 ft) deep. Abrasion (also sometimes called corrasion ) is the process of wind-driven grains knocking or wearing material off of landforms . It was once considered a major contributor to desert erosion, but by the mid-20th Century, it had come to be considered much less important. Wind can normally lift sand only a short distance, with most windborne sand remaining within 50 centimeters (20 in) of

4935-441: Is usually less than the fluid threshold. In other words, there is hysteresis in the wind transport system. Small particles may be held in the atmosphere in suspension. Turbulent air motion supports the weight of suspended particles and allows them to be transported for great distances. Wind is particularly effective at separating sediment grains under 0.05 mm in size from coarser grains as suspended particles. Saltation

5076-782: The American Fur Company founded Fort 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. 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

5217-713: The Bighorn , in southern Montana. Although the business started small, it quickly grew into a thriving trade. Lisa's men started construction of Fort 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. This method was unlike that of the Pacific Northwest fur trade, which involved trappers hired by

5358-885: The Central and Mountain West regions of the United States . The nation's longest, it rises in the eastern Centennial Mountains of the Bitterroot Range of the Rocky Mountains of southwestern Montana , then flows east and south for 2,341 miles (3,767 km) before entering the Mississippi River north of St. Louis , Missouri . The river drains semi-arid watershed of more than 500,000 square miles (1,300,000 km ), which includes parts of ten U.S. states and two Canadian provinces. Although

5499-576: The Columbia 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. 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

5640-543: The Illinoian ) 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. In western Montana, the Missouri River is thought to have once flowed north then east around the Bear Paw Mountains . Sapphires are found in some spots along the river in western Montana. Advances of

5781-515: The Mound builders , stayed along the Missouri, becoming the ancestors of the later Indigenous peoples of the Great Plains. 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

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5922-713: The Niobrara River and many smaller tributaries from the southwest. It then proceeds to form the boundary of South Dakota and Nebraska and is joined by the James River from the north. At Sioux City the Big Sioux River comes in from the north, after which the Missouri forms the Iowa –Nebraska boundary. It flows south to the city of Omaha where it receives its longest tributary, the Platte River , from

6063-551: The North Platte River , is more than twice as long as its mainstream. 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. Thus measured to its highest headwaters, the Missouri River stretches for 2,639 miles (4,247 km). When combined with the lower Mississippi,

6204-544: The Osage and Gasconade Rivers from the south downstream of Jefferson City . The river then rounds the northern side of St. Louis to join the Mississippi River on the border between Missouri and Illinois . 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;

6345-589: The Otoe , Missouria , Omaha , Ponca , Dakota , Lakota , Arikara , Hidatsa , Mandan , Assiniboine , Gros Ventres and Blackfeet . 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,

6486-495: The Pacific 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. As early as the 18th century, fur trappers entered the extreme northern basin of

6627-551: The Platte , Arkansas , and Missouri Rivers. Wind erodes the Earth's surface by deflation (the removal of loose, fine-grained particles by the turbulent action of the wind) and by abrasion (the wearing down of surfaces by the grinding action and sandblasting by windborne particles). Once entrained in the wind, collisions between particles further break them down, a process called attrition . Worldwide, erosion by water

6768-719: The Treaty of Paris , France ceded its Canadian possessions to the British, gaining Louisiana from the Spanish in return. 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 the Hudson's Bay Company in the upper Missouri River watershed was brought back following an expedition by Jacques D'Eglise in

6909-742: The Uncompahgre Uplift . This was likely during the Atokan and Desmoinesian Ages of the Pennsylvianian. The geologic sequences of the coeval Supai and Hermosa Groups. The Supai Group members were created from marine sequences of marine transgression , and regression which produced alternating sandstone , siltstone , and conglomerate subsections . The subsections are sometimes separated by unconformities , due to changing ocean levels, glaciation, or regional subsidence . The ancient off-shore Antler Mountains supplied material from

7050-418: The buffalo , provided meat, clothing, and other everyday items; there were also great riparian areas in the river's floodplain that provided habitat for herbs and other staple foods. 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

7191-538: The fluvial Arikaree Group were deposited between 29 and 19 million years ago. The Miocene -age Ogallala and the slightly younger Pliocene -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; these formations stretch from the Rocky Mountains nearly to the Iowa border and give

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7332-726: The headwaters of the Missouri River first rose in the Laramide Orogeny , a mountain-building episode that occurred from around 70 to 45 million years ago (the end of the Mesozoic through the early Cenozoic ). This orogeny uplifted Cretaceous rocks along the western side of the Western Interior Seaway , a vast shallow sea that stretched from the Arctic Ocean to the Gulf of Mexico, and deposited

7473-438: The wavelength , or distance between adjacent crests, of the ripples. In ripples, the coarsest materials collect at the crests causing inverse grading . This distinguishes small ripples from dunes, where the coarsest materials are generally in the troughs. This is also a distinguishing feature between water laid ripples and aeolian ripples. A sand shadow is an accumulation of sand on the downwind side of an obstruction, such as

7614-403: The windward side. The downwind portion of the dune, the lee slope, is commonly a steep avalanche slope referred to as a slipface . Dunes may have more than one slipface. The minimum height of a slipface is about 30 centimeters. Wind-blown sand moves up the gentle upwind side of the dune by saltation or creep. Sand accumulates at the brink, the top of the slipface. When the buildup of sand at

7755-472: 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. The Missouri's discharge is affected by over 17,000 reservoirs with an aggregate capacity of some 141 million acre-feet (174 km ). By providing flood control,

7896-582: The American West and a flood of settlers, farmers, ranchers, adventurers, hopefuls, financially bereft, and entrepreneurs took their place. The river roughly defined the American 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 the Boonslick . As first area settled by Europeans along

8037-539: The Canadian provinces of Alberta and Saskatchewan . The watershed's largest city is Denver , Colorado, with a population of more than six hundred thousand. Denver is the main city of the Front Range Urban Corridor whose cities had a combined population of over four million in 2005, making it the largest metropolitan area in the Missouri River basin. Other major population centers – mostly in

8178-499: The Earth's total land surface. The sandy areas of today's world are somewhat anomalous. Deserts, in both the present day and in the geological record, are usually dominated by alluvial fans rather than dune fields. The present relative abundance of sandy areas may reflect reworking of Tertiary sediments following the Last Glacial Maximum. Most modern deserts have experienced extreme Quaternary climate change, and

8319-679: The French colonial authorities since 1706, when he deserted his post as commandant of Fort Detroit after poorly handling an attack by the Ottawa that resulted in thirty-one deaths. However, his reputation was enhanced in 1720 when the Pawnee – who had earlier been befriended by Bourgmont – massacred the Spanish Villasur expedition near present-day Columbus, Nebraska , on the Missouri River, temporarily ending Spanish encroachment on French Louisiana. Bourgmont established Fort Orleans ,

8460-541: The Great Plains much of their gentle but persistent eastward tilt, and also constitute a major aquifer. Immediately before the Quaternary Ice Age , the Missouri River was likely split into three segments: an upper portion that drained northwards into Hudson Bay, and middle and lower sections that flowed eastward down the regional slope. As the Earth plunged into the Ice Age, a pre-Illinoian (or possibly

8601-483: The Gulf at the confluence of the Arkansas River with the Mississippi. 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 until Étienne de Veniard, Sieur de Bourgmont commanded an expedition in 1714 that reached at least as far as

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8742-664: The Kansas River and its tributary the Republican River as well as pair of smaller Colorado streams, Big Sandy Creek and the South Platte River , to near Denver. The gold rushes precipitated the decline of the Bozeman Trail as a popular emigration route, as it passed through land held by often-hostile Native Americans. Safer paths were blazed to the Great Salt Lake near Corinne, Utah , during

8883-638: The MacKay and Evans map of the Missouri, although Lewis eventually managed to gain access to it. Meriwether Lewis and William Clark began their famed expedition in 1804 with a party of thirty-three people in three boats. 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

9024-842: The Missouri Breaks, receiving the Marias River from the west then widening into the Fort Peck Lake reservoir a few miles above the confluence with the Musselshell River . Farther on, the river passes through the Fort Peck Dam , and immediately downstream, the Milk River joins from the north. Flowing eastward through the plains of eastern Montana, the Missouri receives the Poplar River from

9165-766: The Missouri River in the hopes of finding populations of beaver and river otter , the sale of whose pelts drove the thriving North 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. 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 of sea otters on

9306-426: The Missouri River, with most of the larger ones coming in as the river draws close to the mouth. 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 and Grand River systems flow from north to south. The Missouri's largest tributaries by runoff are the Yellowstone in Montana and Wyoming,

9447-449: The Missouri and its headwaters form part of the fourth-longest river system in the world , at 3,745 miles (6,027 km). By discharge , the Missouri is the ninth largest river of the United States, after the Mississippi, St. Lawrence , Ohio , Columbia, Niagara , Yukon , Detroit , and St. Clair . The latter two, however, are sometimes considered part of a strait between Lake Huron and Lake Erie . Among rivers of North America as

9588-595: 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. The Missouri's nickname, the "Big Muddy", was inspired by its enormous loads of sediment or silt – some of the largest of any North American river. In its pre-development state, the river transported some 175 to 320 million short tons (159 to 290 million metric tons) per year. The construction of dams and levees has drastically reduced this to 20 to 25 million short tons (18 to 23 million metric tons) in

9729-399: The Missouri to start. 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,

9870-418: The Missouri watershed as well as the neighboring Columbia, Colorado, Arkansas, and Saskatchewan river systems. During this period, the trappers, also called mountain 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

10011-404: The Pacific Northwest coast. In 1807, explorer Manuel 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,

10152-461: 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. "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

10293-452: The Platte and Yellowstone Rivers. Elevations in the watershed vary widely, ranging from just over 400 feet (120 m) at the Missouri's mouth to the 14,293-foot (4,357 m) summit of Mount Lincoln in central Colorado. 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,

10434-577: The Platte in Wyoming, Colorado, and Nebraska, and the Kansas – Republican / Smoky Hill and Osage in Kansas and Missouri. Each of these tributaries drains an area greater than 50,000 square miles (130,000 km ) or has an average discharge greater than 5,000 cu ft/s (140 m /s). The Yellowstone River has the highest discharge, even though the Platte is longer and drains a larger area. In fact,

10575-483: The Platte provided an abundant and reliable source of water for the pioneers as they headed west. Covered wagons, popularly referred to as prairie schooners , provided the primary means of transport until the beginning of regular boat service on the river in the 1850s. During the 1860s, gold strikes in Montana, Colorado, Wyoming, and northern Utah attracted another wave of hopefuls to the region. Although some freight

10716-594: The Rockies in Montana, Idaho and western Wyoming. The Columbia, Missouri and Colorado River watersheds meet at Three Waters Mountain in Wyoming's Wind River Range . South of there, the Missouri basin is bordered on the west by the drainage of the Green 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,

10857-639: The Rockies provide the majority of the flow in the Missouri and its tributaries. The Missouri and many of its tributaries cross the Great Plains, flowing over or cutting into the Ogallala Group and older mid-Cenozoic sedimentary rocks. The lowest major Cenozoic unit, the White River Formation , was deposited between roughly 35 and 29 million years ago and consists of claystone , sandstone , limestone , and conglomerate . Channel sandstones and finer-grained overbank deposits of

10998-419: The Rocky Mountains in Wyoming and Colorado eastward through the Great Plains. An early expedition led by Robert Stuart from 1812 to 1813 proved the Platte impossible to navigate by the dugout 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". Nevertheless,

11139-675: The Sahara that reaches the Amazon Basin . Dust storms on Mars periodically engulf the entire planet. When the Mariner 9 spacecraft entered its orbit around Mars in 1971, a dust storm lasting one month covered the entire planet, thus delaying the task of photo-mapping the planet's surface. Most of the dust carried by dust storms is in the form of silt -size particles. Deposits of this windblown silt are known as loess . The thickest known deposit of loess, up to 350 meters (1,150 ft),

11280-419: The United States during the 19th century. The growth of the fur trade in the early 19th century laid much of the groundwork as trappers explored the region and blazed trails. Pioneers headed west en masse beginning in the 1830s, first by covered wagon , then by the growing numbers of steamboats that entered service on the river. Conflict between settlers and Native Americans in the watershed led to some of

11421-591: The Yellowstone River, which was called Roche 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. In 1795, the young United States and Spain signed Pinckney's Treaty , which recognized American rights to navigate the Mississippi River and store goods for export in New Orleans. Three years later, Spain revoked

11562-462: The Yellowstone's flow is about 13,800 cu ft/s (390 m /s) – accounting for sixteen percent of total runoff in the Missouri basin and nearly double that of the Platte. On the other end of the scale is the tiny Roe River in Montana, which at 201 feet (61 m) long is one of the world's shortest rivers. The table on the right lists the ten longest tributaries of the Missouri, along with their respective catchment areas and flows. Length

11703-442: The air that results in instabilities of the air mass. Dust devils may be as much as one kilometer high. Dust devils on Mars have been observed as high as 10 kilometers (6.2 mi), though this is uncommon. Wind is very effective at separating sand from silt and clay. As a result, there are distinct sandy (erg) and silty (loess) aeolian deposits, with only limited interbedding between the two. Loess deposits are found further from

11844-409: The annual flow of the Mississippi past St. Louis, and as much as 70 percent in certain droughts. In 1990, the Missouri River watershed was home to about 12 million people. 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

11985-556: The arms of the dune. Clay dunes are uncommon but have been found in Africa, Australia, and along the Gulf Coast of North America. These form on mud flats on the margins of saline bodies of water subject to strong prevailing winds during a dry season. Clay particles are bound into sand-sized pellets by salts and are then deposited in the dunes, where the return of the cool season allows the pellets to absorb moisture and become bound to

12126-431: The basin is irrigated. A further 281,000 square miles (730,000 km ) of the basin is devoted to the raising of livestock, mainly cattle. Forested areas of the watershed, mostly second-growth , total about 43,700 square miles (113,000 km ). Urban areas, on the other hand, comprise less than 13,000 square miles (34,000 km ) of land. Most built-up areas are along the main stem and a few major tributaries, including

12267-456: 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 term great bison belt , an area of rich annual grasslands that extended from Alaska to Mexico along

12408-410: The basin. As one of the continent's most significant river systems, the Missouri's drainage basin borders on many other major watersheds of the United States and Canada. The Continental Divide , running along the spine of the Rocky Mountains, forms most of the western border of the Missouri watershed. The Clark Fork and Snake River , both part of the Columbia River basin, drain the area west of

12549-442: The brink exceeds the angle of repose , a small avalanche of grains slides down the slipface. Grain by grain, the dune moves downwind. Dunes take three general forms. Linear dunes, also called longitudinal dunes or seifs, are aligned in the direction of the prevailing winds. Transverse dunes, which include crescent dunes (barchans), are aligned perpendicular to the prevailing winds. More complex dunes, such as star dunes, form where

12690-704: The capital of North Dakota, where the Heart River joins from the west. It slows into the Lake Oahe reservoir just before the Cannonball River confluence. While it continues south, eventually reaching Oahe Dam in South Dakota , the Grand , Moreau and Cheyenne Rivers all join the Missouri from the west. The Missouri makes a bend to the southeast as it winds through the Great Plains, receiving

12831-585: The center of Native American wealth and trade lay along the Missouri River in the Dakotas region on its great bend south. 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. Following the introduction of horses to Missouri River tribes, possibly from feral European-introduced populations, Natives' way of life changed dramatically. The use of

12972-401: The chiefs back to North America. Fort Orleans was either abandoned or its small contingent massacred by Native Americans in 1726. The French 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

13113-462: The continental ice sheets diverted the river and its tributaries, causing them to pool up into large temporary lakes such as Glacial Lakes Great Falls , Musselshell and others. As the lakes rose, the water in them often spilled across adjacent local drainage divides, creating now-abandoned channels and coulees including the Shonkin Sag , 100 miles (160 km) long. When the glaciers retreated,

13254-415: The directions of the winds are highly variable. Additional dune types arise from various kinds of topographic forcing, such as from isolated hills or escarpments. Transverse dunes occur in areas dominated by a single direction of the prevailing wind. In areas where sand is not abundant, transverse dunes take the form of barchans or crescent dunes. These are not common, but they are highly recognizable, with

13395-428: The distinctive crescent shape. Growth is ultimately limited by the carrying capacity of the wind, which as the wind becomes saturated with sediments, builds up the slip face of the dune. Because barchans develop in areas of limited sand availability, they are poorly preserved in the geologic record. Where sand is more abundant, transverse dunes take the form of aklé dunes, such as those of the western Sahara. These form

13536-628: The dune surface. Deserts cover 20 to 25 percent of the modern land surface of the earth, mostly between the latitudes of 10 to 30 degrees north or south. Here the descending part of the tropical atmospheric circulation (the Hadley cell ) produces high atmospheric pressure and suppresses precipitation. Large areas of this desert is floored with windblown sand. Such areas are called ergs when they exceed about 125 square kilometers (48 sq mi) in area or dune fields when smaller. Ergs and dune fields make up about 20% of modern deserts or about 6% of

13677-544: The early 1790s. 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 by Jean-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. Arguably

13818-430: The eastern flank of the Continental Divide. However, after the arrival of Europeans in North America, both the bison and the Native Americans saw a rapid decline in population. 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 as smallpox , raged across

13959-486: The eastern terminus of the First transcontinental railroad via a ferry ride across the Missouri between Council Bluffs, Iowa , and Omaha. The Hannibal 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. True to the then-ideal of Manifest Destiny , over 500,000 people set out from

14100-651: The end of the Pleistocene . During the end of the last glacial period , large migration of humans were taking place, such as those via the Bering 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 the Ohio Valley and the lower Mississippi River Valley, but many, including

14241-423: The first European settlement of any kind on the Missouri River, near present-day Brunswick, Missouri , in 1723. The following year Bourgmont led an expedition to enlist Comanche 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

14382-404: The ground. The minimum wind velocity to initiate transport is called the fluid threshold or static threshold and is the wind velocity required to begin dislodging grains from the surface. Once transport is initiated, there is a cascade effect from grains tearing loose other grains, so that transport continues until the wind velocity drops below the dynamic threshold or impact threshold , which

14523-525: 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. Once, tens of millions of American bison (commonly called buffalo), one of the keystone species of the Great Plains and the Ohio Valley, roamed the plains of the Missouri River basin. Most Native American nations in

14664-477: 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. 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

14805-452: 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. The Missouri's drainage basin has highly variable weather and rainfall patterns, Overall, the watershed is defined by a continental climate with warm, wet summers and harsh, cold winters. Most of

14946-561: 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. In May 1673, the French-Canadian explorer Louis Jolliet and the French explorer Jacques Marquette left the settlement of St. Ignace on Lake Huron and traveled down the Wisconsin and Mississippi Rivers, aiming to reach

15087-421: The local subsidence, or uplift, as well as glaciation, and sea level changes, can cause variations in the deposition sequences of transgression-regressions. The ocean was to the west of the proto-North American continent, but also northwest, or southwest. Aeolian processes Aeolian processes , also spelled eolian , pertain to wind activity in the study of geology and weather and specifically to

15228-679: The lower Missouri 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. From the Rocky Mountains, three streams rise to form the headwaters of the Missouri River: The Missouri River officially starts at the confluence of the Jefferson and Madison in Missouri Headwaters State Park near Three Forks, Montana , and

15369-430: The lowest was 41,690 cu ft/s (1,181 m /s) in 2006. Extremes of the flow vary even further. The largest discharge ever recorded was over 750,000 cu ft/s (21,000 m /s) on July 31, 1993, during a historic flood . The lowest, a mere 602 cu ft/s (17.0 m /s) – caused by the formation of an ice dam – was measured on December 23, 1963. The Rocky Mountains of southwestern Montana at

15510-525: The margins of dune fields, although they also occur within ergs. Conditions that favor the formation of sand sheets, instead of dunes, may include surface cementation, a high water table, the effects of vegetation, periodic flooding, or sediments rich in grains too coarse for effective saltation. A dune is an accumulations of sediment blown by the wind into a mound or ridge . They differ from sand shadows or sand drifts in that they are independent of any topographic obstacle. Dunes have gentle upwind slopes on

15651-546: The most longstanding and violent of the American Indian Wars . During the 20th century, the Missouri River basin was extensively developed for irrigation, flood control, and the generation of hydroelectric power . Fifteen dams impound the main stem of the river, with hundreds more on tributaries. Meanders have been cut off and the river channelized to improve navigation, reducing its length by almost 200 miles (320 km) from pre-development times. Although

15792-534: The most successful of the Missouri Company expeditions was that of James MacKay and John Evans . 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

15933-436: The mouth of the Platte River. It is unclear exactly how far Bourgmont traveled beyond there; he described the blond-haired Mandans in his journals, so it is likely he reached as far as their villages in present-day North Dakota. Later that year, Bourgmont published The 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

16074-442: The mouth, is 21,920 cu ft/s (621 m /s). This is from a drainage area of 186,400 sq mi (483,000 km ), or 35% of the total river basin. 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 m /s). The river here drains about 484,100 sq mi (1,254,000 km ), representing about 91% of the entire basin. The lowermost gage with

16215-505: The native tribes that lived along them, are still in use today. The expedition's discoveries eventually found their way to cartographer Guillaume Delisle , who used the information to create a map of the lower Missouri. In 1718, Jean-Baptiste Le Moyne, Sieur de Bienville requested that the French government bestow upon Bourgmont the Cross of St. Louis because of his "outstanding service to France". Bourgmont had in fact been in trouble with

16356-543: The north before crossing into North Dakota where the Yellowstone River , its greatest tributary by volume, joins from the southwest. At the confluence, the Yellowstone is actually the larger river. The Missouri then meanders east past Williston and into Lake Sakakawea , the reservoir formed by Garrison Dam . Below the dam the Missouri receives the Knife River from the west and flows south to Bismarck ,

16497-526: The one which produced the 1972 Black Hills flood through Rapid City, South Dakota . 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

16638-545: The original source of sediments than ergs. An example of this is the Sand Hills of Nebraska , US. Here vegetation-stabilized sand dunes are found to the west and loess deposits to the east, further from the original sediment source in the Ogallala Formation at the feet of the Rocky Mountains. Some of the most significant experimental measurements on aeolian landforms were performed by Ralph Alger Bagnold ,

16779-460: The present climate and the forces that molded it. For example, vast inactive ergs in much of the modern world attest to late Pleistocene trade wind belts being much expanded during the Last Glacial Maximum. Ice cores show a tenfold increase in non-volcanic dust during glacial maxima. The highest dust peak in the Vostok ice cores dates to 20 to 21 thousand years ago. The abundant dust is attributed to

16920-467: The present day. Much of this sediment is derived from the river's floodplain , 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. Despite this,

17061-526: The prevailing wind. They form mostly in softer material such as silts. Abrasion produces polishing and pitting, grooving, shaping, and faceting of exposed surfaces. These are widespread in arid environments but geologically insignificant. Polished or faceted surfaces called ventifacts are rare, requiring abundant sand, powerful winds, and a lack of vegetation for their formation. In parts of Antarctica wind-blown snowflakes that are technically sediments have also caused abrasion of exposed rocks. Attrition

17202-424: 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 km ) from mainstem reservoirs alone. The United States Geological Survey operates fifty-one stream gauges along the Missouri River. The river's average discharge at Bismarck, 1,314.5 miles (2,115.5 km) from

17343-577: The river it was largely populated by slave-owning southerners following the Boone's Lick Road . The major trails for the opening of the American West all have their starting points on the river, including the California , Mormon , Oregon , and Santa Fe trails. The first westward leg of the Pony Express was a ferry across the Missouri at St. Joseph, Missouri . Similarly, most emigrants arrived at

17484-493: The river still transports more than half the total silt that empties into the Gulf of Mexico; the Mississippi River Delta , formed by sediment deposits at the mouth of the Mississippi, constitutes a majority of sediments carried by the Missouri. 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

17625-498: The river town of Independence, 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 the California Gold Rush , for example. For most, the route took them up the Missouri to Omaha, Nebraska, where they would set out along the Platte River , which flows from

17766-409: The sediments that are now being churned by wind systems were generated in upland areas during previous pluvial (moist) periods and transported to depositional basins by stream flow. The sediments, already sorted during their initial fluvial transport, were further sorted by wind, which also sculpted the sediments into eolian landforms. Missouri River The Missouri River is a river in

17907-453: The sediments that now underlie much of the drainage basin of the Missouri River. This Laramide uplift caused the sea to retreat and laid the framework for a vast drainage system of rivers flowing from the Rocky and Appalachian Mountains , the predecessor of the modern-day Mississippi watershed. The Laramide Orogeny is essential to modern Missouri River hydrology , as snow and ice melt from

18048-614: The size of the Canadian province of Quebec , the watershed encompasses most of the central Great Plains, stretching from the Rocky Mountains in the west to the Mississippi River Valley in the east and from the southern extreme of western Canada to the border of the Arkansas River watershed. Compared with the Mississippi River above their confluence, the Missouri is twice as long and drains an area three times as large. The Missouri accounts for 45 percent of

18189-613: The surface and practically none normally being carried above 2 meters (6 ft). Many desert features once attributed to wind abrasion, including wind caves, mushroom rocks , and the honeycomb weathering called tafoni , are now attributed to differential weathering, rainwash, deflation rather than abrasion, or other processes. Yardangs are one kind of desert feature that is widely attributed to wind abrasion. These are rock ridges, up to tens of meters high and kilometers long, that have been streamlined by desert winds. Yardangs characteristically show elongated furrows or grooves aligned with

18330-519: The treaty and in 1800 secretly returned Louisiana to Napoleonic France in the Third 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. Fearing that the cutoffs could occur again, President Thomas Jefferson proposed to buy the port of New Orleans from France for $ 10 million. Instead, faced with

18471-533: The upper Mississippi, drain most of the area bordering the eastern side of the Missouri River basin. Finally, on the south, the Ozark Mountains and other low divides through central Missouri, Kansas and Colorado separate the Missouri watershed from those of the White River and Arkansas River, also tributaries of the Mississippi River. Over 95 significant tributaries and hundreds of smaller ones feed

18612-506: The various fur enterprises, namely Hudson's Bay . Fort Raymond was later replaced by Fort Lisa at the confluence of the Missouri and Yellowstone in North Dakota; a second fort also called Fort Lisa was built downstream on the Missouri River in Nebraska. In 1809 the St. Louis Missouri Fur Company was founded by Lisa in conjunction with William Clark and Pierre Choteau, among others. In 1828,

18753-442: The watershed receives an average of 8 to 10 inches (200 to 250 mm) of precipitation each year. 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). 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 summer thunderstorms such as

18894-447: The watershed's southeastern portion – include Omaha, 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. In contrast, the northwestern part of the watershed

19035-544: The watershed, with most leading a nomadic lifestyle and dependent on enormous bison herds that roamed through the Great 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 the Louisiana Purchase . The Missouri River was one of the main routes for the westward expansion of

19176-609: The west of the ancestral West Coast. The North American continent supplied material from the east. Three other basins were formed at the same time: the Paradox Basin of eastern Utah, the Central Colorado Basin in Colorado, and the Oquirrh Basin in northwest Utah. Because marine transgressions cover distances, over time, the coeval units are separated by distance, and type of deposition material;

19317-535: The west. Downstream, it begins to define the border between the states of Nebraska and Missouri , then flows between the states of Missouri and Kansas . The Missouri swings east at Kansas City , where the Kansas 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, the Grand River . It passes south of Columbia and receives

19458-464: The wind's ability to shape the surface of the Earth (or other planets ). Winds may erode , transport, and deposit materials and are effective agents in regions with sparse vegetation , a lack of soil moisture and a large supply of unconsolidated sediments . Although water is a much more powerful eroding force than wind, aeolian processes are important in arid environments such as deserts . The term

19599-555: The wind. Sand sheets are flat or gently undulating sandy deposits with only small surface ripples. An example is the Selima Sand Sheet in the eastern Sahara Desert, which occupies 60,000 square kilometers (23,000 sq mi) in southern Egypt and northern Sudan . This consists of a few feet of sand resting on bedrock. Sand sheets are often remarkably flat and are sometimes described as desert peneplains . Sand sheets are common in desert environments, particularly on

19740-675: Was hauled overland, most transport to and from the gold fields was done through the Missouri and Kansas Rivers, as well as the Snake River in western Wyoming and the Bear River in Utah, Idaho, and Wyoming. 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

19881-457: Was such that the water was made muddy by it and could not clear itself." They recorded Pekitanoui or Pekistanoui 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

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