Great Plains
[8] The Great Plains consist of a broad stretch of country underlain by nearly horizontal strata extending westward from the 97th meridian west to the base of the Rocky Mountains, a distance of 300 to 500 mi (480 to 800 km).There are also the occasional lava-capped mesas and dike formed ridges, surmounting the general level by 500 ft (150 m) or more and manifestly demonstrating the widespread erosion of the surrounding plains.It appears to have suffered a regional uplift or increase in elevation, for the upper Missouri River and its branches no longer flow on the surface of the plain, but in well graded, maturely opened valleys, several hundred feet below the general level.A significant exception to the rule of mature valleys occurs, however, in the case of the Missouri, the largest river, which is broken by several falls on hard sandstones about 50 mi (80 km) east of the mountains.The next following harder strata have been sufficiently eroded to disclose the core of underlying igneous and metamorphic crystalline rocks in about half of the domed area.[9] In the intermediate section of the plains, between latitudes 44° and 42°, including southern South Dakota and northern Nebraska, the erosion of certain large districts is peculiarly elaborate.That is, this section was once smoothly covered with a gently sloping plain of gravel and sand that had been spread far forward on a broad denuded area as a piedmont deposit by the rivers which issued from the mountains.While the northern section owes its smoothness to the removal of local gravels and sands from a formerly uneven surface by the action of degrading rivers and their inflowing tributaries, the southern section owes its smoothness to the deposition of imported gravels and sands upon a previously uneven surface by the action of aggrading rivers and their outgoing distributaries.However, the lower lands which surround it on all sides place it in such strong relief that it stands up as a table-land, known from the time of Mexican occupation as the Llano Estacado.On the east, it is strongly undercut by the retrogressive erosion of the headwaters of the Red, Brazos, and Colorado rivers of Texas and presents a ragged escarpment approximately 500 to 800 ft (150 to 240 m) high, overlooking the central denuded area of that state.There, between the Brazos and Colorado rivers, occurs a series of isolated outliers capped by limestone that underlies both the Llano Uplift on the west and the Grand Prairies escarpment on the east.Between these two similar areas, in the space limited by the Canadian and Red Rivers, rise the subdued forms of the Wichita Mountains in Oklahoma, the westernmost member of the Ouachita system.In this context, the High Plains, as well as Southern Alberta, south-western Saskatchewan and Eastern Montana are mainly semi arid steppe land and are generally characterised by rangeland or marginal farmland.[15] The prairie rattlesnake (Crotalus viridis) ranges throughout much of the Great Plains and into the valleys and lower elevations of the eastern Rocky Mountains and portions of the American southwest.[24] During the Cretaceous Period (145–66 million years ago), the Great Plains were covered by a shallow inland sea called the Western Interior Seaway.United States: Canada: the Great Plains biome is found to be at the brink of collapse due to woody plant encroachment, with 62% of Northern American grassland lost to date.[35][36] The introduction of corn around 800 CE allowed the development of the mound-building Mississippian culture along rivers that crossed the Great Plains and that included trade networks west to the Rocky Mountains.Eastern portions of the Great Plains were inhabited by tribes who lived at Etzanoa and in semi-permanent villages of earth lodges, such as the Arikara, Mandan, Pawnee, and Wichita.[citation needed] Wars with the Ojibwe and Cree peoples pushed the Lakota (Teton Sioux) west onto the Great Plains in the mid- to late-17th century.[42] The first known contact between Europeans and Indians in the Great Plains occurred in what is now Texas, Kansas, and Nebraska from 1540 to 1542 with the arrival of Francisco Vázquez de Coronado, a Spanish conquistador.[48] On the northeastern Plains of Canada, the Indians were less favored, with families owning fewer horses, remaining more dependent upon dogs for transporting goods, and hunting bison on foot.[49] Comanche power peaked in the 1840s when they conducted large-scale raids hundreds of miles into Mexico proper, while also warring against the Anglo-Americans and Tejanos who had settled in independent Texas.The United States acquired the Louisiana Purchase in 1803 and conducted the Lewis and Clark Expedition in 1804–1806, and more information became available concerning the Plains, and various pioneers entered the areas.The Homestead Acts of 1862 further encouraged settlement and agricultural development in the Great Plains; the population of Nebraska, for instance, increased from under 30,000 in 1860 to over one million in 1890.This rapid population influx and agricultural expansion was a hallmark of the settlement and development of the Great Plains in the late 19th century, as the region attracted waves of new settlers from Germany, Scandinavia, and Russia, as well as farmers who sold land in older states to move to larger farms.Some of the first built were: The railroads opened up the Great Plains for settlement, making it possible to ship wheat and other crops at low cost to the urban markets in the East and overseas.On the plains, very few single men attempted to operate a farm or ranch by themselves; they understood the need for a hard-working wife and numerous children to handle the many responsibilities.[61] The eastern image of farm life in the prairies emphasized the isolation of the lonely farmer and wife, yet plains residents created busy social lives for themselves.Progressives believed that the government could play a role in solving these problems by regulating businesses, protecting workers, and providing social welfare programs.Center pivot irrigation is used extensively in drier sections of the Great Plains, resulting in aquifer depletion at a rate that is greater than the ground's ability to recharge.
Great Plains (disambiguation)Llano Estacadothe MidwestrabbitbrushCole CampMissouriPrairie dogkeystone speciesNorth DakotaTheodore Roosevelt National ParkGreat Plains State ParkOklahomaFort SmithMontanaMissouri RiverflatlandNorth AmericaRocky MountainsprairiesteppegrasslandInterior Plainsmixed grass prairietallgrass prairieGreat LakesAppalachian PlateauTaiga PlainsBoreal PlainsNorthern CanadaecoregionCentral United StatesWestern CanadaU.S. statesKansasNebraskaSouth DakotaColoradoWyomingNew MexicoMinnesotaCanadian provincesAlbertaSaskatchewanManitobaCanadian Prairieshuman geographyPlains IndiansPlains statesNatural Resources CanadaAtlas of CanadaNorth American Environmental AtlasCommission for Environmental CooperationNorth American Free Trade AgreementAmerican bisonUniversity of Nebraska–Lincoln96th meridian westNevin Fenneman'sMidwestern statesHigh PlainsUnited States Geological SurveyMissouri CoteauBlack HillsSand Hillseastern New MexicoTexas PanhandleSmoky HillsColorado PiedmontPecos ValleyEdwards PlateauCentral TexasCypress HillsManitoba EscarpmentRocky Mountain Foothillsstrata97th meridian westaltitudesemi-arid climateerosionalbuttesescarpmentsclimatictopographicrainfallCanadian Shieldaspen parklandprairie ecoregionlatitude 44°CretaceousTertiaryerosionPleistoceneice sheetBlack Elk Peakigneousmetamorphiclatitudes 44°BadlandsNicodemuslatitudes 42°fluviatileMesa de MayaRaton MesaLake LawtonkaMount ScottCanadian RiverPecos RiverLlano UpliftRio GrandeembaymentWichita MountainsSouthern AlbertaEastern Montanasemi aridrangelandfarmlanddroughtdust stormshumid subtropical climatehumid continental climatethunderstormstornadoTornado AlleyNorth American Prairies provinceAppalachiansNew YorkOregon