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78-836: Although the Rocky Mountain Front is clearly distinct from both plains and mountains , in places like the Wyoming Basin , Montana , and New Mexico it is more ambiguous. One definition of the front is that it is a "transition zone between the Rocky Mountains and the mixed grass prairie ... [that] encompasses a wide variety of wetland, riparian, grassland, and forested habitats". By one estimate there are more than 2,000,000 acres (8,100 km) of Rocky Mountain Front land in Montana and Canada. The Rocky Mountain Front

156-701: A 120-mile (190 km) stretch of the Clark Fork River. It includes the Berkeley Pit , a former copper mine one mile (1.6 km) across that now holds heavily acidic (pH = 2.5) water 900 feet (270 m) in depth. Areas of relatively intact grassland and wetland on the Rocky Mountain Front include the Pine Butte Swamp Preserve near Choteau, Montana , parts of the Blackfeet Indian Reservation , and

234-445: A broad denuded area as a piedmont deposit by the rivers which issued from the mountains. Since then, it has been more or less dissected by the erosion of valleys. The central section of the plains thus presents a marked contrast to the northern section. 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,

312-828: A broad expanse of flatland in North America . The region is located just to the east of the Rocky Mountains , much of it covered in prairie , steppe , and grassland . They are the western part of the Interior Plains , which include the mixed grass prairie , the tallgrass prairie between the Great Lakes and Appalachian Plateau , and the Taiga Plains and Boreal Plains ecozones in Northern Canada . "Great Plains", or Western Plains ,

390-538: 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). It extends northward from the Mexican boundary far into Canada. Although the altitude of the plains increases gradually from 600 ft (180 m) or 1,200 ft (370 m) on the east to 4,000–5,000 ft (1,200–1,500 m) or 6,000 ft (1,800 m) near

468-603: A gradual transition, this rainfall line may be taken to divide the drier plains from the moister prairies. However, in Canada the eastern boundary of the plains is well defined by the presence of the Canadian Shield to the northeast. The plains (within the United States) may be described in northern, intermediate, central and southern sections, in relation to certain peculiar features. In Canada, no such division

546-861: A number of other hills and valleys of southwestern Montana including the Centennial Mountains , the Big Hole River and parts of the Madison River valleys. Protected areas include Red Rock Lakes National Wildlife Refuge in Centennial Valley, Pine Butte Swamp, the CSKT Bison Range in western Montana and a number of Bureau of Land Management wilderness study areas . 45°31′N 112°21′W  /  45.517°N 112.350°W  / 45.517; -112.350 Great Plains The Great Plains are

624-645: A region of human geography , referring to the Plains Indians or the Plains states . In Canada the term is rarely used; Natural Resources Canada , the government department responsible for official mapping, treats the Interior Plains as one unit consisting of several related plateaus and plains. There is no region referred to as the "Great Plains" in the Atlas of Canada . In terms of human geography,

702-594: A west-northwest direction in what is now Oklahoma and Texas which is now known as the De Soto Trail. The Spanish thought that the Great Plains were the location of the mythological Quivira and Cíbola , a place said to be rich in gold. People in the southwest began to acquire horses in the 16th century by trading or stealing them from Spanish colonists in New Mexico. As horse culture moved northward,

780-404: Is about 500 mi (800 km) east to west and 2,000 mi (3,200 km) north to south. Much of the region was home to American bison herds until they were hunted to near extinction during the mid/late-19th century. It has an area of approximately 500,000 sq mi (1,300,000 km ). Current thinking regarding the geographic boundaries of the Great Plains is shown by this map at

858-556: Is also the ecoregion of the Great Plains or alternatively the western portion of the Great Plains. The Great Plains lie across both the Central United States and Western Canada , encompassing: The term "Great Plains" is used in the United States to describe a sub-section of the even more vast Interior Plains physiographic division, which covers much of the interior of North America. It also has currency as

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936-526: Is extraordinarily smooth. It is very dry, except for occasional shallow and temporary water sheets after rains. Llano is separated from the plains on the north by the mature consequent valley of the Canadian River , and from the mountains on the west by the broad and probably mature valley of the Pecos River . On the east, it is strongly undercut by the retrogressive erosion of the headwaters of

1014-547: Is heavily deformed by faulting , folding , and overthrusting . During the Sevier orogeny mountain-building event about 115 and 55 million years ago, what is known as the Cordilleran foreland thrust-and-fold event occurred along the east side of the Rocky Mountains in northwest Montana. The thrust-and-fold belt does not extend all the way south through Montana. Instead, it cuts west above Three Forks continues south—crossing

1092-781: Is most intense in southwestern Montana, specifically in the Bitterroot Valley around Missoula and the area just north of Yellowstone National Park along the Gallatin River , namely in Bozeman and the resort town of Big Sky , and the Yellowstone River in Paradise Valley . The area contains the largest and most expensive Superfund toxic waste site in the United States. The Clark Fork River Superfund Complex consists of three major sites along

1170-506: Is peculiarly elaborate. Known as the Badlands , it is a minutely dissected form with a relief of a few hundred feet. This is due to several causes: The central section of the Great Plains, between latitudes 42° and 36° , occupying eastern Colorado and western Kansas , is mostly a dissected fluviatile plain. That is, this section was once smoothly covered with a gently sloping plain of gravel and sand that had been spread far forward on

1248-545: Is such an important geologic feature that it affects the weather in North America. Warm air masses moving from the Gulf of Mexico are blocked by the front from moving west, causing hail , thunderstorms , tornadoes , and other kinds of violent weather which then move east. " Tornado Alley ", that part of the Great Plains where tornadoes are most frequent, is a direct outcome of the front's effect on weather. In Alberta ,

1326-455: Is used: the climatic and vegetation regions are more impactful on human settlement than mere topography, and therefore the region is split into (from north to south), the taiga plains, boreal plains , aspen parkland , and prairie ecoregion regions. The northern section of the Great Plains, north of latitude 44° , includes eastern Montana , eastern Wyoming , most of North Dakota and South Dakota , southwestern Minnesota and portions of

1404-563: The American burying beetle (Nicrophorus americus), Salt Creek Tiger Beetle (Cinidela nevadica lincolniana), Great Plains Giant Tiger Beetle (Amblycheila chylindriformis), Microstylum morosum , Bean leaf beetle (Cerotoma trifurcata), Great Plains Camel Cricket (Daihinia brevipes), and the Great plains spittlebug (Lepyronia gibbosa). Some species in the Great plains have gone extinct in

1482-593: The Arikara , Mandan , Pawnee , and Wichita . Wars with the Ojibwe and Cree peoples pushed the Lakota (Teton Sioux) west onto the Great Plains in the mid- to late-17th century. The Shoshone originated in the western Great Basin and spread north and east into present-day Idaho and Wyoming. By 1500, some Eastern Shoshone had crossed the Rocky Mountains into the Great Plains. After 1750, warfare and pressure from

1560-701: The Clark Fork / Bitterroot River systems among others. The ecoregion also contains outlying disconnected areas of similar habitat such as valleys of the Bow River in Alberta. The area has a moderate climate, warmed by the Chinook wind which brings dry, warm summers (average 14 °C) and winters that are mild for this latitude (ave. -8 °C). While the dominant vegetation are grasses such as rough fescue with Parry's oatgrass and Koeleria (June grasses)

1638-825: The Department of the Interior . In contrast, U.S. Forest Service , an agency of the U. S. Department of Agriculture , administers the National Forests and National Grasslands, under a multiple-use concept. By law, the U.S. Forest Service must consider all resources, with no single resource emphasized to the detriment of others, including water, soil, grazing, timber harvesting, and minerals (mining and drilling), as well as recreation and conservation of fish and wildlife. Each individual state also administers state lands, typically smaller areas, for various purposes including conservation and recreation. Grasslands are among

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1716-968: The Great Plains toad ( Anaxyrus cognatus ), plains leopard frog ( Lithobates blairi ), and plains spadefoot toad ( Spea bombifrons ). Some species predominately associated with various river basins in the Great Plains include sturgeon chub ( Macrhybopsis gelida ), peppered chub ( Macrhybopsis tetranema ), prairie chub ( Macrhybopsis australis ), western silvery minnow ( Hybognathus argyritis ), plains minnow ( Hybognathus placitus ), smalleye shiner ( Notropis buccula ), Arkansas River shiner ( Notropis girardi ), Red River shiner ( Notropis bairdi ), Topeka shiner ( Notropis topeka ), plains topminnow ( Fundulus sciadicus ), plains killifish ( Fundulus zebrinus ), Red River pupfish ( Cyprinodon rubrofluviatilis ), and Arkansas darter ( Etheostoma cragini ). The great plains also has many invertebrate species living here both alive and extinct such as

1794-559: The Lewis and Clark Expedition in the early 19th century but which now remain in small numbers only. Another iconic mammal found here are the grizzly bears , which come down from the mountainsides to forage in the rich habitats of rivers and grasslands. This is the last remaining area in the United States where grizzlies come down to the Great Plains. Other mammals of the valleys include white-tailed deer , wolves , mountain lions , mule deer , pronghorn and ground squirrels . Birds spotted in

1872-581: The Snake River Plain and skirting the west side of the Colorado Plateau before cutting west again to enter California . Although most of this mountain-building has since been obliterated by additional orogeny and volcanic activity, most of it still exists in northwestern Montana. The Rocky Mountain Front in this area represents some of the highest changes of elevation within a short distance anywhere in North America. Much of this part of

1950-495: The "Crown of the Continent Ecosystem". This area of Montana is prime habitat for wildlife, including the black bear , cougar , deer , elk , grizzly bear , lynx , moose , wolf , and wolverine . It is one of the few places in North America where grizzly bear habitat still extends onto the prairie. Extensive numbers of prairie rattlesnake are also found there. Heavy coal, oil, and natural gas development along

2028-434: The "Great Plains" as an ecoregion synonymous with predominant prairies and grasslands rather than as physiographic region defined by topography. The Great Plains ecoregion includes five sub-regions: Temperate Prairies, West-Central Semi-Arid Prairies, South-Central Semi-Arid Prairies, Texas Louisiana Coastal Plains, and Tamaulipas-Texas Semi-Arid Plain, which overlap or expand upon other Great Plains designations. The region

2106-520: The 1950s, and built a sweetening plant there in 1957. The Pincher Creek Gas Field can produce up to 150 million cubic feet of natural gas per day, and in the 1960s Shell Oil built a second sweetening plant near Waterton Lakes National Park . The Rocky Mountain Front in British Columbia and Alberta has long been inhabited by Plains Indians, and the area contains widely scattered but not uncommon Native American rock art sites. Development along

2184-556: The Blackfoot, Crow, Lakota, Cheyenne, and Arapaho pushed Eastern Shoshone south and westward. Some of them moved as far south as Texas, emerging as the Comanche by 1700. 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. In that same period, Hernando de Soto crossed

2262-503: The Canadian provinces including southeastern Alberta , southern Saskatchewan and southwestern Manitoba . The strata here are Cretaceous or early Tertiary , lying nearly horizontal. The surface is shown to be a plain of degradation by a gradual ascent here and there to the crest of a ragged escarpment, the escarpment-remnant of a resistant stratum. There are also the occasional lava -capped mesas and dike formed ridges, surmounting

2340-520: The Centennial Valley for example include grouse , sandhill crane and trumpeter swan . About 25% of the original grassland remains (less than 10% in Canada) and continues to decrease due to the rapid growth of the Rockies' population. Expansion of cities in both Montana and Alberta is removing habitat and blocking the movements of native species including grizzly bears, elk, mule deer and others. Growth

2418-462: The Center for Great Plains Studies, University of Nebraska–Lincoln . This definition, however, is primarily ecological, not physiographic. The Boreal Plains of Western Canada are physiographically the same, but differentiated by their tundra and forest (rather than grassland) appearance. The term "Great Plains", for the region west of about the 96th meridian west and east of the Rocky Mountains ,

Rocky Mountain Front - Misplaced Pages Continue

2496-557: The Comanche were among the first to commit to a fully mounted nomadic lifestyle. This occurred by the 1730s, when they had acquired enough horses to put all their people on horseback. The real beginning of the horse culture of the plains began with the Pueblo Revolt of 1680 in New Mexico and the capture of thousands of horses and other livestock. In 1683 a Spanish expedition into Texas found horses among Native people. In 1690,

2574-551: The Great Plains and into the valleys and lower elevations of the eastern Rocky Mountains and portions of the American southwest . Other snakes include the plains hog-nosed snake ( Heterodon nasicus ), western milksnake ( Lampropeltis gentilis ), great plains ratsnake ( Pantherophis emoryi ), bullsnake ( Pituophis catenifer sayi ), plains black-headed snake ( Tantilla nigriceps ), plains gartersnake ( Thamnophis radix ), and lined snake ( Tropidoclonion lineatum ). Reptile diversity increases significantly in southern regions of

2652-564: The Great Plains and that included trade networks west to the Rocky Mountains. Mississippians settled the Great Plains at sites now in Oklahoma and South Dakota . Siouan language speakers may have originated in the lower Mississippi River region. They were agriculturalists and may have been part of the Mound Builder civilization during the 9th–12th centuries. Pressure from other Indian tribes, themselves driven west and south by

2730-588: The Great Plains include National Parks and National Monuments, administers by the National Park Service with the responsibility of preserving ecological and historical places and making them available to the public. The U.S. Fish & Wildlife Service manages the National Wildlife Refuges, with the primary responsibility of conserving and protecting fish, wildlife, plants, and habitat in the public trust. Both are agencies of

2808-476: The Great Plains include the swift fox ( Vulpes velox ) and the endangered black-footed ferret ( Mustela nigripes ). The lesser prairie chicken ( Tympanuchus pallidicinctus ) is endemic to the Great Plains and the distribution of the greater prairie chicken ( Tympanuchus cupido ) predominantly occurs in the region, although the latter historically ranged further eastward. The Harris's sparrow ( Zonotrichia querula ) spends winter months in southern areas of

2886-512: The Great Plains is the most tornado active area in the world and is sometimes referred to as Tornado Alley . The Great Plains are part of the floristic North American Prairies province , which extends from the Rocky Mountains to the Appalachians . Although the American bison ( Bison bison ) historically ranged throughout much of North America (from New York to Oregon and Canada to northern Mexico), they are strongly associated with

2964-751: The Great Plains where they once roamed in immense herds. Pronghorn ( Antilocapra americana ) range into western areas of the region. The black-tailed prairie dog ( Cynomys ludovicianus ) is another iconic species among several rodents that are linked to the region including the thirteen-lined ground squirrel ( Ictidomys tridecemlineatus ), spotted ground squirrel ( Xerospermophilus spilosoma ), Franklin's ground squirrel ( Poliocitellus franklinii ), plains pocket gopher ( Geomys bursarius ), hispid pocket mouse ( Chaetodipus hispidus ), olive-backed pocket mouse ( Perognathus fasciatus ), plains pocket mouse ( Perognathus flavescens ), and plains harvest mouse ( Reithrodontomys montanus ), Two carnivores associated with

3042-488: The Great Plains. The ornate box turtle ( Terrapene ornata ) and great plains skink ( Plestiodon obsoletus ) occur in southern areas. Although few salamanders are strongly associated with region, the western tiger salamander ( Ambystoma mavortium ) ranges through much of the Great Plains and the Rocky Mountains, as does the Rocky Mountain toad ( Anaxyrus w. woodhousi ). Other anurans related to region include

3120-503: The High Plains) is periodically subjected to extended periods of drought ; high winds in the region may then generate devastating dust storms . The eastern Great Plains near the eastern boundary falls in the humid subtropical climate zone in the southern areas, and the northern and central areas fall in the humid continental climate . Many thunderstorms occur in the plains in the spring through summer. The southeastern portion of

3198-650: 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. The southern and narrow part of

Rocky Mountain Front - Misplaced Pages Continue

3276-674: The Rocky Mountain Front extends from the west-northcentral part of the border with Wyoming south to the city Pueblo and the Arkansas River . Peaks within the front include Pikes Peak , Mount Blue Sky , and Longs Peak . Just east of the Rocky Mountain Front is the Colorado Piedmont , and within the Piedmont is the most heavily urbanized part of the United States between Chicago and the West Coast. The only pass through

3354-492: The Rocky Mountain Front in Montana began in the 1970s. By the early 2000s, there were estimates of as much as 2.2 trillion cubic feet of natural gas below the front in Montana, although only 200 billion cubic feet was available on leasable land. By 2003, much of the Rocky Mountain Front in the state consisted of land owned by the U.S. federal government and managed by the United States Forest Service and

3432-400: The Rocky Mountain Front in Montana. The spectacular scenery also led to the creation of a number of guest ranches in the area, and some of the state's best-known guest ranches are near Choteau and Augusta . The Rocky Mountain Front in Montana contains some of the last relatively untouched native prairies in the northern Great Plains . The front forms the eastern boundary of what is called

3510-502: The Rocky Mountain Front is about 12 to 19 miles (19 to 31 km) wide. As early as 1935, it was well-recognized that significant coal resources underlay the Rocky Mountain Front in Alberta. As of 2013, about 60 percent of all Canadian coal reserves are believed to be beneath the front in Alberta. Natural gas is also very plentiful. Royal Dutch Shell began producing natural gas there in the Pincher Creek Gas Field in

3588-824: The Rocky Mountains in the area is the Tennessee Pass . The Rocky Mountain Front forms the eastern boundary of a triangular area of volcanic activity centered on western Colorado. Several sandstone horizons underlie the Colorado Rocky Mountain Front as well, and decline steeply to the east. "The Rocky Mountain Front" is the title of an essay by noted Montana author A. B. Guthrie Jr. It first appeared in Montana, The Magazine of Western History in 1987. Montana valley and foothill grasslands The Montana valley and foothill grasslands are an ecoregion of northwestern North America in

3666-653: The area of the ancient Great Plains for thousands to millions of years. The vast majority of these animals became extinct in North America at the end of the Pleistocene (around 13,000 years ago). A number of significant fossil sites are located in the Great Plains including Agate Fossil Beds National Monument ( Nebraska ), Ashfall Fossil Beds ( Nebraska ), Clayton Lake State Park ( New Mexico ), Dinosaur Valley State Park ( Texas ), Hudson-Meng Bison Kill (Nebraska), Makoshika State Park (Montana), and The Mammoth Site ( South Dakota ). Public and protected lands in

3744-471: The central section, it is for the most part a dissected fluviatile plain. 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 . It measures roughly 150 mi (240 km) east-west and 400 mi (640 km) north-south. It is of very irregular outline, narrowing to

3822-476: The ecoregion contains parts of the Prairie Pothole Region , large areas of wetland and rich grass on the Rocky Mountain Front steppe. Traditionally the grassland was reduced and then renewed by a combination of heavy grazing by bison and other ungulates and regular fires. The traditional wildlife of this area of included the large herds American bison , elk and bighorn sheep observed during

3900-531: The encroachment of European settlers as well as economic incentives such as the fur trade, alongside the arrival of the horse and firearms from Europe pushed multiple tribes onto the Great Plains. Among those to have lived on the Great Plains were the Blackfoot , Crow , Sioux , Cheyenne , Arapaho , Comanche , and others. Eastern portions of the Great Plains were inhabited by tribes who lived at Etzanoa and in semi-permanent villages of earth lodges, such as

3978-440: The federal Bureau of Land Management (BLM). By one count, BLM alone managed 13,000 acres (53 km) of land on the Rocky Mountain Front in the state. Beginning in 2001, petroleum exploration was banned for a six-year period on Forest Service land in the front. In the fall of 2002, BLM issued new regulations making it easier to engage in oil and gas production along the Montana front. Conservationists have actively worked to protect

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4056-402: The foothills are rich in plant life with, for example, 487 species of plant counted in southwest Montana 's Centennial Valley . The ecoregion also contains sagebrush country in the higher and drier valleys in the rain shadow of the Rockies such as the upper Madison , Ruby and Red Rock Rivers , which are a similar habitat to the neighbouring Snake-Columbia shrub steppe ecoregion. Finally

4134-625: The front is somewhat limited. In the 1940s, planners considered building the Alaska Highway along the Rocky Mountain Front in British Columbia and Alberta but ultimately decided on a coastal route. In the early 2000s, the Nature Conservancy was working to secure environmental easements along the front in Alberta to protect grizzly bear habitat. The Rocky Mountain Front in Montana from the Canada–US border south to about Helena

4212-581: The front, including the Lewis Range and Livingston Range , has suffered heavy glaciation . According to a definition used by the Christian Science Monitor , the Rocky Mountain Front in Montana extends only about 100 miles (160 km) south of the state's northern border. But professors Tony Prato and Dan Fagre define the front in Montana as being 50 miles (80 km) wide and 200 miles (320 km) long. Ranches cover much of

4290-433: The general level by 500 ft (150 m) or more and manifestly demonstrating the widespread erosion of the surrounding plains. All these reliefs are more plentiful towards the mountains in central Montana. The peneplain is no longer in the cycle of erosion that witnessed its production. It appears to have suffered a regional uplift or increase in elevation, for the upper Missouri River and its branches no longer flow on

4368-426: The great plains like the Rocky Mountain Locust (Melanoplus spretus). During the Cretaceous Period (145–66 million years ago), the Great Plains were covered by a shallow inland sea called the Western Interior Seaway . However, during the Late Cretaceous to the Paleocene (65–55 million years ago), the seaway had begun to recede, leaving behind thick marine deposits and a relatively flat terrain which

4446-501: The largest group. They rise like a large island from the sea, occupying an oval area of about 100 mi (160 km) north-south by 50 mi (80 km) east-west. At Black Elk Peak , they reach an altitude of 7,216 ft (2,199 m) and have an effective relief over the plains of 2,000 or 3,000 ft (610 or 910 m) This mountain mass is of flat-arched, dome-like structure, now well dissected by radiating consequent streams. The weaker uppermost strata have been eroded down to

4524-468: The least protected biomes. Humans have converted much of the prairies for agricultural purposes or to create pastures. Several of the protected lands in the region are centered around aberrant and uncharacteristic features of the region, such as mountains, outcrops, and canyons (e.g. Devil's Tower National Monument , Wind Cave National Park , Scotts Bluff National Monument ), and as splendid and worthy as they are, they are not primarily focused on conserving

4602-426: The level of the plains where their upturned edges are evenly truncated. 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. 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

4680-424: The line that divides the Great Plains into an area that receives 20 in (510 mm) or more of rainfall per year and an area that receives less than 20 in (510 mm). 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 . The region (especially

4758-570: The more common "prairie". The Great Plains are the westernmost portion of the vast North American Interior Plains , which extend east to the Appalachian Plateau . The United States Geological Survey divides the Great Plains in the United States into ten physiographic subdivisions: Further to this can be added Canadian physiographic sub-regions such as the Alberta Plain, Cypress Hills , Manitoba Escarpment (eastward), Manitoba Plain, Missouri Coteau (shared), Rocky Mountain Foothills (eastward), and Saskatchewan Plain. The Great Plains consist of

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4836-442: The mountains, the local relief is generally small. The semi-arid climate excludes tree growth and opens far-reaching views. The plains are by no means a simple unit. They are of diverse structure and of various stages of erosional development. They are occasionally interrupted by buttes and escarpments . They are frequently broken by valleys. Yet on the whole, a broadly extended surface of moderate relief so often prevails that

4914-436: The name, Great Plains, for the region as a whole is well-deserved. The western boundary of the plains is usually well-defined by the abrupt ascent of the mountains. The eastern boundary of the plains (in the United States) is more climatic than topographic . The line of 20 in (510 mm) of annual rainfall trends a little east of northward near the 97th meridian. If a boundary must be drawn where nature presents only

4992-429: The northern United States and southern Canada . This area consists of rolling grassy hills and river valleys of the Rocky Mountains foothills in the US state of Montana and the Canadian province of Alberta . The area largely consists of the Rocky Mountain Front , where the Great Plains rise to meet the Rockies, and is thus near the Continental Divide . The foothills are drained by the upper Missouri River and

5070-434: The plains and prairies. 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. The first Peoples ( Paleo-Indians ) arrived on the Great Plains thousands of years ago. The introduction of corn around 800 CE allowed the development of the mound-building Mississippian culture along rivers that crossed

5148-576: The region from energy exploration. Southwest Wyoming, where the borders of Idaho , Utah , and Wyoming come together, is another area where the Cordilleran foreland thrust-and-fold remains largely intact. (The other is northwest Montana, as noted above.) The Rocky Mountain Front in Wyoming is believed to have extensive oil and natural gas reserves. In the late 1970s, the U.S Forest Service and Bureau of Land Management attempted to open these lands to energy exploration. This led to extensive litigation and changes in federal land use regulations. In Colorado ,

5226-647: The region. Other species migrate from the south in the spring and spend their breeding season on the plains, including the white-faced ibis ( Plegadis chihi ), mountain plover ( Charadrius montanus ), marbled godwit ( Limosa fedoa ), Sprague's pipit ( Anthus spragueii ), Cassin's sparrow ( Peucaea cassinii ), Baird's sparrow ( Centronyx bairdii ), lark bunting ( Calamospiza melanocorys ), chestnut-collared longspur ( Calcarius ornatus ), thick-billed longspur or McCown's longspur ( Rhynchophanes mccownii ), and dickcissel ( Spiza americana ). The prairie rattlesnake ( Crotalus viridis ) ranges throughout much of

5304-474: The river from a better graded preglacial valley by the Pleistocene ice sheet . Here, the ice sheet overspread the plains from the moderately elevated Canadian highlands far on the north-east, instead of from the much higher mountains nearby on the west. The present altitude of the plains near the mountain base is 4,000 ft (1,200 m). The northern plains are interrupted by several small mountain areas. The Black Hills, chiefly in western South Dakota, are

5382-456: The seaway had once occupied. During the Cenozoic era , specifically about 25 million years ago during the Miocene and Pliocene epochs, the continental climate became favorable to the evolution of grasslands. Existing forest biomes declined and grasslands became much more widespread. The grasslands provided a new niche for mammals, including many ungulates and glires , that switched from browsing diets to grazing diets. Traditionally,

5460-405: The south. Its altitude is 5,500 ft (1,700 m) at the highest western point, nearest the mountains whence its gravels were supplied. From there, it slopes southeastward at a decreasing rate, first about 12 ft (3.7 m), then about 7 ft/mi (1.3 m/km), to its eastern and southern borders, where it is 2,000 ft (610 m) in altitude. Like the High Plains farther north, it

5538-459: 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. The two sections are also alike in that residual eminences still here and there surmount the peneplain of the northern section, while the fluviatile plain of the central section completely buried the pre-existent relief. An exception to this statement must be made for

5616-416: The southwest, close to the mountains in southern Colorado, where some lava-capped mesas ( Mesa de Maya , Raton Mesa ) stand several thousand feet above the general plain level, and thus testify to the widespread erosion of this region before it was aggraded. The southern section of the Great Plains, between latitudes 35.5° and 25.5°, lies in western Texas , eastern New Mexico , and western Oklahoma . Like

5694-588: The spread of grasslands and the development of grazers have been strongly linked. However, an examination of mammalian teeth suggests that it is the open, gritty habitat and not the grass itself which is linked to diet changes in mammals, giving rise to the " grit, not grass " hypothesis. Paleontological finds in the area have yielded bones of mammoths , saber-toothed cats and other ancient animals, as well as dozens of other megafauna (large animals over 100 lb [45 kg]) – such as giant sloths , horses , mastodons , and American lion – that dominated

5772-602: The subdued forms of the Wichita Mountains in Oklahoma , the westernmost member of the Ouachita system. The term "Western Plains" is used to describe the ecoregion of the Great Plains, or alternatively the western portion of the Great Plains. In general, the Great Plains have a wide range of weather, with very cold and harsh winters and very hot and humid summers. Wind speeds are often very high, especially in winter. The 100th meridian roughly corresponds with

5850-464: 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. This peculiar feature is explained as the result of displacement of

5928-590: The table-land, called the Edwards Plateau , is more dissected than the rest, and falls off to the south in a frayed-out fault scarp. This scarp overlooks the coastal plain of the Rio Grande embayment . The central denuded area, east of the Llano, resembles the east-central section of the plains in exposing older rocks. Between these two similar areas, in the space limited by the Canadian and Red Rivers, rise

6006-530: The term prairie is more commonly used in Canada, and the region is known as the Canadian Prairies , prairie provinces or simply "the prairies". The North American Environmental Atlas , produced by the Commission for Environmental Cooperation , a North American Free Trade Agreement (NAFTA) agency composed of the geographical agencies of the Mexican, American, and Canadian governments, uses

6084-637: Was not generally used before the early 20th century. Nevin Fenneman's 1916 study Physiographic Subdivision of the United States brought the term Great Plains into more widespread usage. Before that the region was almost invariably called the High Plains, in contrast to the lower Prairie Plains of the Midwestern states . Today the term " High Plains " is used for a subregion of the Great Plains. The term still remains little-used in Canada compared to

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