longest river north_america rising rocky_mountains western montana missouri flows east south miles entering mississippi_river north missouri river takes drainage sparsely populated semi arid watershed half million square miles km2 includes parts states canadian provinces combined lower mississippi_river forms world fourth longest river system years people depended tributaries source transportation major groups native americans populated watershed leading nomadic lifestyle dependent enormous buffalo great plains europeans encountered river late seventeenth century region passed spanish french hands finally united_states missouri long believed water route atlantic pacific lewis clark travel river entire length confirmed mythical legend main routes westward expansion united_states 19th century growth fur trade early 1800s laid explored region trails pioneers headed west beginning 1830s covered wagon growing numbers entering service river native american lands watershed taken settlers leading longstanding violent wars indigenous peoples american history 20th century basin extensively developed irrigation flood control generation hydroelectric power dams main stem river hundreds tributaries cut river improve navigation reducing length miles pre development times lower missouri valley populous highly productive agricultural industrial region heavy development taken toll wildlife fish populations water quality course rocky_mountains montana wyoming streams rise form longest begins near spring feet sea level southeastern slopes flowing west north runs west swings northeast finally joins form jefferson originates madison lake wyoming national park joins form madison rises national park streams flow north northwest montana missouri river officially starts confluence jefferson madison missouri state park near montana joined mile downstream missouri passes reservoir west issuing mountains near cascade river flows northeast city drops great falls missouri series substantial winds east scenic region known receiving west widening fort lake reservoir miles confluence farther river passes fort dam immediately downstream joins north flowing eastwards plains eastern montana missouri receives north crossing greatest tributary volume joins southwest confluence actually larger river missouri east past reservoir formed dam missouri receives west flows south capital joins west lake reservoir confluence continues south eventually reaching dam grand join missouri west missouri makes bend southeast winds great plains receiving smaller tributaries southwest proceeds form boundary nebraska joined north forms iowa nebraska boundary big river comes north missouri flows south city receives longest tributary west downstream begins define nebraska missouri border flows missouri kansas missouri swings east kansas_city enters west north central missouri east kansas_city missouri receives left passes south columbia receives rivers south downstream river rounds northern join mississippi_river border missouri illinois watershed drainage basin spanning square miles km2 missouri river encompasses nearly sixth area united_states percent continent north_america comparable size canadian province quebec watershed encompasses central stretching rocky_mountains west east southern extreme western canada border arkansas river watershed compared mississippi_river confluence missouri twice long drains area times large missouri accounts percent annual flow mississippi past percent certain missouri river watershed home million people included entire population state nebraska parts states colorado iowa kansas minnesota missouri montana wyoming small southern portions canadian provinces alberta watershed largest city denver colorado population thousand denver main city corridor cities combined population million making largest metropolitan area basin major population centers located southeastern portion watershed include nebraska situated north confluence missouri kansas_city missouri kansas_city kansas located confluence missouri metropolitan area situated south mouth mississippi contrast northwestern watershed sparsely populated northwestern cities montana fastest growing missouri basin square miles km2 missouri river watershed includes roughly fourth agricultural land united_states providing country wheat square miles km2 farmland basin square miles km2 basin devoted raising livestock mainly cattle forested areas watershed second growth total square miles km2 urban areas hand comprise square miles km2 land built areas located main stem major tributaries including rivers elevations watershed vary widely ranging feet missouri mouth foot summit central colorado river drops total feet spring source plains watershed extremely little local vertical relief land rises feet mile east west elevation feet eastern border watershed feet sea level places base missouri drainage basin highly variable weather rainfall patterns overall watershed defined continental climate warm wet summers harsh cold winters watershed receives average inches precipitation year westernmost portions basin southeastern regions missouri receive inches vast majority precipitation occurs winter upper basin known short lived intense summer thunderstorms produced flood winter temperatures montana wyoming colorado drop low summer highs kansas missouri reached times continent significant river systems missouri drainage basin borders major united_states canada running spine rocky_mountains forms western border missouri watershed snake river basin drain area west montana idaho western wyoming columbia missouri meet waters mountain wyoming south missouri basin bordered west drainage tributary colorado south colorado colorado flow pacific_ocean large drainage called great divide basin exists missouri green western wyoming area counted missouri river watershed waters flow north lower separates missouri river watershed tributary smaller tributaries north streams canada drainage basin large basins missouri nelson southern alberta minnesota tributaries upper mississippi drain area bordering eastern basin finally south low divides central missouri kansas colorado separate missouri watershed tributaries mississippi_river major tributaries significant tributaries hundreds smaller ones feed missouri river larger ones coming river draws close mouth rivers streams basin flow west east following great plains eastern tributaries james big systems flow north south missouri largest tributaries runoff montana wyoming wyoming colorado nebraska kansas republican kansas missouri tributaries drains area greater square miles km2 average discharge greater highest discharge longer drains larger area fact flow accounting sixteen percent total runoff missouri basin nearly double end scale tiny montana feet long world shortest rivers table right lists longest tributaries missouri respective areas flows length measured source regardless naming convention main stem example miles long including longest tributaries mile mile brings total length miles similar naming issues encountered longest tributary twice long mainstream missouri extend farther upstream main stem measured source spring miles long measured highest stretches miles combined lower mississippi missouri form fourth longest river system world miles discharge discharge missouri ninth largest river united_states mississippi ohio columbia detroit considered rivers north_america missouri thirteenth largest mississippi ohio columbia detroit missouri drains predominantly semi arid region discharge lower variable north american rivers comparable length construction dams river flooded twice year april rise spring fresh melting snow plains watershed june rise caused summer rocky_mountains far destructive river increasing times normal discharge years missouri discharge affected aggregate capacity million acre feet providing flood control dramatically reduce peak flows increase low flows significantly reduces river runoff causing annual loss million acre feet united_states geological survey operates stream river average discharge miles mouth drainage area km2 total river basin kansas_city miles mouth river average flow river drains km2 representing entire basin period record greater years missouri miles upstream mouth missouri average annual flow km2 watershed lies highest annual mean lowest extremes flow vary largest discharge recorded july historic flood lowest mere caused formation ice dam measured december upper lower missouri river north hydroelectric dam river upstream iowa lower river miles meets mississippi hydroelectric lock dams wing dams enable barge traffic directing flow river foot wide foot deep channel wing dams place maintained corps engineers currently plans construct lock dams replace wing dams list locks dams list locks dams geology rocky_mountains southwestern montana missouri river rose mountain building episode occurred million years ago end early cretaceous rocks western vast shallow sea stretched gulf_of_mexico deposited sediments drainage basin caused sea retreat laid framework vast drainage system rivers flowing rocky predecessor modern day mississippi watershed essential modern snow ice melt provide majority flow missouri tributaries missouri tributaries cross great plains flowing cutting older mid rocks lowest major unit deposited roughly million years ago consists sandstone limestone channel finer deposits deposited million years ago age slightly younger deposited atop formed material eroded rocky_mountains time increased generation relief formations stretch rocky_mountains nearly iowa border great plains gentle persistent eastward tilt constitute major immediately likely split segments upper portion drained northwards middle lower sections flowed eastward regional slope earth ice age pre possibly diverted missouri river present confluence mississippi caused integrate single river system cuts regional slope western montana thought flowed north east found spots river western montana advances continental ice sheets diverted river tributaries causing pool large temporary lakes lakes rose water adjacent local drainage divides creating abandoned channels including miles long glaciers retreated missouri flowed new course south lower tributary took original main channel missouri nickname big muddy inspired enormous loads sediment largest north american river pre development state river transported million short tons year construction dams drastically reduced million short tons present day sediment derived river called belt time river changed course tons soil rocks banks river kept reaching natural sediment sources course missouri trap roughly million short tons sediment year despite river transports half total gulf_of_mexico formed sediment deposits mouth mississippi constitutes majority sediments carried missouri peoples archaeological evidence especially missouri suggests man presence watershed missouri river years ago end pleistocene end glacial period great migration humans began traveling land bridge americas traveled slowly centuries missouri river formed main migration paths settled lower including mound builders stayed missouri ancestors later indigenous peoples great plains native americans lived missouri access ample food water shelter migratory animals inhabited plains time providing meat clothing everyday items great areas river provided natural herbs staple foods written records tribes peoples pre european period exist use writing according writings explorers major tribes missouri river included natives missouri limited extent path trade transport addition river tributaries formed tribal boundaries lifestyles indigenous centered semi nomadic culture tribes different summer winter camps center native american wealth trade lay region great bend south large cluster walled villages situated islands river home thousands later served market trading post early french british explorers fur traders following introduction horses tribes possibly feral european introduced populations natives way life changed dramatically use horse allowed travel greater distances facilitated hunting communications trade tens millions american commonly called buffalo species plains basin native american groups basin relied heavily food source hides bones served create household items time species came benefit indigenous peoples periodic controlled surrounding missouri clear old dead growth large population region gave rise term great belt area rich annual extended alaska mexico eastern flank arrival europeans north_america native americans saw rapid decline population hunting eliminated populations east mississippi_river reduced numbers missouri basin mere foreign diseases smallpox land native american populations left primary source remaining indigenous people amalgamated areas reservations early european explorers french explorers left settlement traveled wisconsin aiming reach pacific_ocean late june documented european according journals flood saw terrific wrote entire trees mouth missouri attempt cross great danger water muddy clear recorded local missouri party explored missouri mouth area addition later learned mississippi drained gulf_of_mexico pacific originally presumed expedition turned miles short gulf confluence mississippi france expanded territorial claims north_america include land western mississippi_river included lower portion missouri missouri remained formally commanded expedition reached far mouth unclear exactly far traveled described blond haired journals likely reached far villages present day later year published ascend known document use names gave tributaries native tribes lived use today expedition discoveries eventually found way information create map lower missouri requested french government outstanding service france fact trouble french colonial authorities deserted post commandant poorly handling attack ottawa resulted thirty deaths reputation enhanced earlier befriended spanish expedition near present day columbus nebraska temporarily ending spanish french louisiana established european settlement kind near present day missouri following year led expedition enlist support spanish continued interest taking missouri brought chiefs tribes visit france raised rank nobility accompany chiefs north_america abandoned small contingent native americans french indian war erupted territorial disputes france great_britain north_america reached head france defeated greater strength british army forced canadian possessions english louisiana spanish treaty paris amounting colonial holdings north_america initially spanish extensively explore missouri let french traders continue activities license ended news incursions upper watershed brought following expedition early spanish chartered missouri popularly referred offered reward person reach pacific_ocean missouri expeditions led simon far north villages central arguably successful expeditions set missouri established miles south present day winter camp villages expelled british traders talking populace location called french evans failed accomplish original goal reaching pacific create accurate map upper young united_states spain signed treaty recognized american rights navigate mississippi_river store goods export new_orleans years later spain revoked treaty secretly returned louisiana treaty transfer secret spanish continued administer territory spain restored rights use mississippi new_orleans united_states fearing occur president proposed buy port new_orleans france million instead faced debt crisis napoleon offered sell entirety louisiana including million amounting acre deal signed doubling size united_states acquisition jefferson instructed lewis explore missouri search water route pacific_ocean discovered system drains pacific similar latitude widely believed connection short existed spain takeover citing formally returned louisiana french spanish authorities warned lewis journey forbade seeing evans map missouri lewis eventually managed gain access lewis began famed expedition party thirty people boats europeans travel entire length missouri reach pacific_ocean columbia found trace maps lewis clark especially pacific_northwest region provided foundation future explorers negotiated relations multiple native american tribes wrote extensive reports climate ecology geology region present day names geographic features upper missouri basin originated expedition american frontier fur trade early 18th century fur entered extreme northern basin hopes finding populations beaver river sale drove thriving north american fur trade came different places canadian fur corporations pacific_northwest maritime fur trade united_states stay area long failed find significant resources glowing reports country rich thousands game animals came lewis returned year expedition journals described lands rich thousands buffalo beaver river abundant population sea pacific_northwest coast explorer organized expedition lead explosive growth fur trade upper country lisa crew traveled missouri trading manufactured items return local native american tribes established fort confluence tributary southern montana business started small quickly grew thriving trade lisa men started construction fort sat bluff overlooking confluence fall fort serve primarily trading post native americans method unlike pacific northwest fur trade involved hired fur enterprises hudson bay later replaced fort lisa confluence missouri second fort called fort lisa built downstream nebraska founded lisa conjunction founded confluence missouri gradually main headquarters fur trade upper missouri basin fur trapping activities early 19th century encompassed nearly rocky_mountains eastern western slopes hudson bay company north west company outfits worked thousands streams missouri watershed neighboring columbia colorado arkansas river systems period called mountain men trails wilderness later form paths pioneers settlers travel west transport thousands beaver required ships providing large motives river transport missouri start 1830s drew close fur industry slowly began die silk replaced beaver fur desirable clothing item time beaver population streams rocky_mountains intense hunting furthermore frequent native american attacks trading posts dangerous employees fur companies regions industry continued 1840s valley declines beaver population contributed earlier demise fur trade finally disappeared great plains primary center industry shifting central canada despite demise prosperous trade legacy led opening american west flood settlers farmers financially took place settlers pioneers river roughly defined american frontier 19th century particularly downstream kansas_city takes sharp eastern turn heart state missouri major trails opening american west starting points river including california oregon trails westward leg ferry missouri missouri similarly arrived eastern terminus railroad ferry ride missouri iowa bridge bridge cross location major reason kansas_city largest city river upstream mouth true ideal people set river town independence missouri destinations american west 1830s 1860s people reasons embark year long journey economic crisis later gold strikes including example route took missouri nebraska set flows rocky_mountains wyoming colorado eastwards early expedition led proved impossible navigate let large later missouri increasing numbers explorer remarked thick drink thin provided abundant reliable source water pioneers headed west covered wagons popularly referred prairie provided primary means transport beginning regular boat service river 1850s 1860s gold strikes montana colorado wyoming northern utah attracted wave region freight hauled overland transport gold fields missouri western wyoming utah idaho wyoming estimated passengers freight hauled midwest montana percent transported boat journey took days upstream direction route directly west colorado lay tributary pair smaller colorado streams near denver gold rushes precipitated decline popular emigration route passed land held hostile native americans safer paths great salt lake near utah gold rush period led large scale settlement rocky_mountains region settlers expanded holdings ran land conflicts native american tribes resulted frequent raids armed conflicts leading federal government creating multiple treaties plains tribes generally involved establishing borders lands indigenous treaties native americans soon broken leading huge wars battles big small fought military native americans tribes forced land reservations conflicts natives settlers opening wyoming montana led fought fighting resulted complete native american victory treaty fort signed guaranteed use regions surrounding northern native americans white intervention significant landmark divides northeastern kansas western missouri pro slavery forces missouri cross river kansas spark bleeding kansas leading continued tension hostility today kansas missouri significant military engagement period battle affect native americans turning point american civil war allowed union seize control transport river state missouri joining confederacy peace freedom native americans long great war sparked american miners discovered gold western eastern wyoming lands originally set aside native american use treaty fort settlers lands attacked native americans troops sent area protect miners drive natives new settlements bloody period native americans military won victories major battles resulting loss nearly thousand lives war eventually ended american victory opened settlement native americans region relocated reservations wyoming southeastern montana dam building era late 19th early 20th centuries great number dams built course missouri transforming percent river chain river development stimulated variety factors growing demand electricity rural northwestern parts basin floods plagued rapidly growing agricultural urban areas lower small privately owned hydroelectric projects existed 1890s large flood control storage dams characterize middle reaches river today constructed 1950s dams built vicinity generate power great falls missouri chain giant formed river path western montana built dam missouri replaced modern structure dam little small atop missouri flow power plant largest dams built dam lies directly foot largest missouri period private establishments notably began develop power generation small run river structure completed near present site second dam built missouri rock filled timber dam generated seven half electricity surrounding countryside nearby steel finished failed structural deficiencies causing catastrophic flooding way downstream past section black eagle dam save nearby factories rebuilt concrete gravity structure stands day miles downstream hydroelectric dam built stretch completed river power company reservoir flooded gates mountains limestone canyon lewis described remarkable seen tow ing projecting rocks places ready began construction modern dam provide flood control area rising waters submerged old dam powerhouse stands underwater miles upstream present day dam missouri temperament uncertain actions jury state woman mind march missouri basin suffered series catastrophic floods turn 20th century notably great depression era new deal completed montana construction massive public works project provided jobs laborers depression major step providing flood control lower half fort controls runoff percent missouri river watershed little effect severe flood struck lower basin years later event particularly destructive submerged manufacturing plants kansas_city greatly delaying shipments military supplies world war flooding damages mississippi missouri river system primary reasons congress passed opening way develop missouri massive scale act authorized pick missouri basin program pick plan composite widely varying proposals pick plan emphasis flood control hydroelectric power called construction large storage dams main stem missouri plan stressed development local irrigation included provisions roughly smaller dams tributaries early stages pick development tentative plans build low dam missouri smaller dams tributaries met controversy inhabitants basin eventually proposed solution greatly increase size proposed dam today replacing storage provided dams decision longest free flowing river united_states 1950s construction commenced dams garrison big bend fort point proposed pick plan integrated unit pick plan 1940s dams form known dams chiefly garrison largest dams world volume rank biggest nation holding million acre feet total store years worth river flow measured dam capacity makes largest reservoir system united_states largest north_america addition storing irrigation water system includes annual flood control reservation million acre feet power plants generate billion annually equal constant output nearly smaller dams tributaries kansas system provides irrigation water nearly km2 land table left lists statistics dams ordered downstream run river dams missouri marked yellow form small given names unnamed left blank dams upper half river lower river longstanding use shipping channel navigation shipping achieved expectations best circumstances huge industry executive director boat travel missouri started wood framed bull boats native americans thousands years introduction larger craft river colonization great plains missouri independence started running missouri 1830s large mail freight carrying vessels running regularly kansas_city traveled farther upstream handful able river far eastern montana early 19th century height fur trade began traveling nearly length missouri montana rugged mouth carrying beaver buffalo areas frequented resulted development specialized carrying boats travel dismantled sold lumber arrival water transport increased 1850s multiple craft pioneers miners runs independence near people set overland large shallow river described pioneers mile wide inch deep magnificent useless rivers navigation peaked boats operating time missouri smaller vessels earlier vessels built transferred missouri preferred larger mississippi ohio greater industry success guarantee safety early decades river flow controlled man rises falls massive amounts sediment prevented clear view wrecked vessels dangers navigating average ship lifespan short years development marked beginning end commerce missouri trains number boats slowly left 1890s transport agricultural mining products barge saw revival early twentieth century passage beginning 20th century missouri river extensively engineered water transport purposes percent river flows artificially straightened channels authorized maintain missouri depth feet port kansas city mouth distance miles accomplished constructing wing dams direct river flow straight narrow channel prevent began project widen river navigation channel feet years later began deep water channel kansas_city modifications reduced river length miles late 19th century miles present day construction dams missouri pick plan mid twentieth century final step aiding navigation large system help provide flow maintain navigation channel year round capable halting river annual high low water cycles missouri notably protracted century drought basin historic floods difficult massive system control began permanently increase river navigation channel width feet depth feet work continues day mile navigation channel controlled building rock direct river flow sediments sealing cutting channels missouri resisted efforts control depth boats ran aground navigation channel severely blamed failing maintain channel minimum depth estimated total goods shipped river annually million tons million metric tons providing widespread consensus creation navigation channel shipping traffic far lower expected shipments including produce manufactured items lumber oil averaged tons year transported material missouri far largest user river accounting percent river traffic kansas percent nebraska percent iowa percent barge traffic ships sand gravel lower miles river remaining portion shipping channel sees little use commercial vessels traffic decline goods shipped barges seen decline 1960s present 1960s predicted increase million short tons year instead opposite happened goods million short tons million short tons largest drops agricultural products especially wheat reason land missouri developed fraction potential barges missouri hauled short tons products equal daily freight traffic mississippi drought conditions early 21st century competition modes transport mainly railroads primary reason decreasing river traffic missouri failure consistently maintain navigation channel hampered industry currently efforts revive shipping industry efficiency river transport haul agricultural products alternative transportation routes solutions expanding navigation channel releasing water peak navigation season considered drought conditions lifted short tons missouri representing significant increase shipments flooding closed record stretches river boat traffic wash ing away hopes bounce year lock dams lower plenty wing dams river harder barges navigate contrast upper mississippi locks dams averaged million tons cargo annually locks closed winter ecology natural history historically thousands square miles comprised missouri river supported wide range plant animal species biodiversity generally increased proceeding downstream cold montana temperate moist climate missouri today river zone consists primarily types trees maple ash average tree height generally increases farther limited distance land adjacent river vulnerable soil erosion floods large sediment concentrations missouri support aquatic invertebrates basin support species birds species fish endangered missouri aquatic habitats support species mammals river divides missouri river watershed freshwater upper missouri lower missouri central prairie upper missouri roughly encompassing area montana wyoming southern alberta comprises mainly sparse biodiversity ice age known endemic species region little precipitation watershed middle missouri extending colorado southwestern minnesota northern kansas nebraska parts wyoming iowa greater rainfall characterized temperate forests plant life diverse home twice animal species finally central prairie situated lower missouri encompassing parts missouri kansas oklahoma arkansas despite large seasonal temperature fluctuations region greatest diversity plants animals thirteen species endemic lower missouri human impacts beginning river commerce industrial development 1800s missouri severely water quality degraded human activity river habitat long gone replaced agricultural land development led increasing amounts people infrastructure areas high risk constructed river order channel consequences faster stream velocity resulting increase peak flows downstream areas runoff causes elevated levels nitrogen nutrients major problem especially iowa missouri form pollution heavily affects upper mississippi illinois low oxygen levels rivers vast gulf_of_mexico dead zone end results high nutrient concentrations missouri tributaries mississippi lower missouri waters river narrower deeper accessible flora fauna numerous dams bank projects constructed facilitate conversion acres km2 agricultural land channel control significantly reduced volume sediment transported downstream river eliminated critical habitat fish birds amphibians early 21st century declines populations native species prompted issue biological opinion recommending restoration river habitats federally endangered bird fish species began work ecosystem restoration projects lower early 21st century low use shipping channel lower missouri maintained considered feasible remove wing dams river flow allowing naturally restore banks acres km2 riverside undergoing active restoration restoration projects mobilized sediments trapped bank structures prompting concerns exacerbated nutrient sediment pollution locally downstream northern gulf_of_mexico report assessed roles sediment evaluating current habitat restoration strategies alternative ways manage sediment report found better understanding sediment processes including creation sediment budget accounting sediment transport erosion deposition volumes length provide foundation projects improve water quality standards protect endangered species tourism recreation km2 open water provide main recreational areas basin increased million visitor hours mid-1960s million visitor hours development visitor facilities spurred required build maintain boat ramps public facilities major recreational use estimated contribute million regional economy year lewis historic trail miles long follows nearly entire mouth source route lewis extending illinois east oregon west follows portions mississippi columbia rivers trail spans states maintained federal state government agencies passes historic sites notably archaeological locations including parts river designated recreational use consists portions missouri downstream fort point dams total miles reaches exhibit islands underwater rocks common features lower river disappeared destroyed scattered reaches river downstream montana miles river course rugged series known river designated national wild flows acre km2 preserve comprising steep cliffs deep arid plains archaeological sites missouri preserve includes wide variety plant animal life recreational activities include boating hiking wildlife observation north central montana acres km2 miles comprise wildlife refuge consists native northern great plains ecosystem heavily affected human development construction designated trails preserve open hiking camping national parks national park rocky mountain national park national park watershed parts rivers basin set aside preservation recreational use notably mile protected stretch missouri longest tributaries missouri flows past national include missouri montana big village site nebraska
Missouri River