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North American Cordillera

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North American Cordillera
Highest point
PeakDenali
Elevation6,168 m (20,236 ft)
Dimensions
Length6,400 km (4,000 mi)
Geography
The mountainous western part of North America is called a "cordillera".
CountriesUnited States, Canada and Mexico

TheNorth American Cordillera,sometimes also called theWestern Cordillera of North America,theWestern Cordillera,or thePacific Cordillera,[1][2]is theNorth Americanportion of theAmerican Cordillera,the mountain chain system along thePacific coastof theAmericas.The North American Cordillera covers an extensive area ofmountain ranges,intermontanebasins,andplateausinWesternandNorthwestern Canada,Western United States,andMexico,including much of the territory west of theGreat Plains.

The precise boundaries of this cordillera and its subregions, as well as the names of its various features, may differ depending on the definitions in each country or jurisdiction, and also depending on the scientific field; this cordillera is a particularly prominent subject in the scientific field ofphysical geography.[3][4]

Major features

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Physiographic divisionsof the western United States include three mountain systems: theRocky Mountain System(areas 16–19), theCascadeSierra Nevada(23), and thePacific Border Province(24).
Physiographic divisions of Mexico include three mountain systems: theSierra Madre Oriental,theSierra Madre Occidentaland theSierra Madre del Sur(which is an extension of thePeninsular Ranges).

The North American Cordillera extends from theU.S. stateofAlaskato the southern border ofMexico,and includes some of the highest peaks on the continent.[5]Its mountain ranges generally run north to south along three main belts: thePacific Coast Rangesin the west, the Nevadan belt in the middle (including theSierra Nevada), and the Laramide belt in the east (including theRocky Mountains).[6][7][8]

These threeorogenic belts(also called "orogens" ) arose due to the engagement oftectonic plateswhich deformed the Earth'slithosphere(crust and uppermost mantle). For example, theLaramide orogenychanged thetopographyof the central Rocky Mountains and adjoining Laramide regions (from central Montana to central New Mexico) during theLate Cretaceous80 million years ago.[9]Prior to this time the Rocky Mountain region was occupied by a broad basin. Further topographical evolution occurred during theEocene(55–50 million years ago) andOligocene(34–23 million years ago), but since that time the region has been relatively stable.[10][11][12][13]Generally speaking, it will be convenient here to consider these three belts going west to east, and north to south.

InAlaska,south of the Interior Plains area, is the Rocky Mountain System, then the Intermontane Basins and Ranges, and in the southern part of the state are the Pacific Mountains and Valleys.[14]In theAlaska panhandle,the mainland mountain ranges and offshore islands (theAlexander Archipelago) are extensions of respective ranges further south.[15]

In Canada, the North American Cordillera is usually divided into three physiographic regions: the western system, the interior system, and the eastern system.[16]The western system includes theCoast Mountains,the interior system includes theColumbia Mountains,and the eastern system includes theCanadian Rockies.[3]

At its midsection betweenSan Francisco,CaliforniaandDenver,Colorado,the North American Cordillera is about 1,000 miles (1,600 km) wide, and its physiographic provinces at this midpoint are as follows, going from west to east: the Pacific Coast Ranges, theCentral Valley,the Sierra Nevada, theBasin and Range Province(forming many narrow ranges and valleys), theColorado Plateau,and the Rocky Mountains.[5]In the United States, another major feature of the Cordillera is theColumbia Plateau,located north of California between theCascade Range– which is a northern extension of the Sierra Nevada[17]– and the Rocky Mountains.

In Mexico, theSierra Madre Occidental,and theSierra Madre Orientalfurther east, surround theMexican Plateau.[17][18]To the west of the Sierra Madre Occidental, thePeninsular Rangesborder the Pacific Ocean, and theSierra Madre del Suris the southern extension of the Peninsular Ranges.[19]Sierra Madre means "Mother Range" in Spanish.

The Nevadan belt runs up and down the middle of the North American Cordillera. Therefore, the intermontane areas of the cordillera can be divided up into the areas east of the Nevadan belt, and those west of the Nevadan belt.

Pacific Coast Belt

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The Pacific Coast Ranges, comprising the Pacific Coast Belt, parallel the North American Pacific Coast, and comprise several mountain systems. Along theBritish Columbiaand Alaska coast, the mountains intermix with the sea in a complex maze offjords,with thousands of islands. Off the Southern California coast theChannel Islandsarchipelagoof theSanta Monica Mountainsextends for 160 miles (260 km).

Southern Alaska ranges

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In southern Alaska, the primary mountain ranges are theAlaska Range,Wrangell Mountains,Saint Elias Mountains,Kenai Mountains,Chugach Mountains,andTalkeetna Mountains.[20][21]

Western System of Canada

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Mount Robsonin British Columbia

TheYukon Rangescomprise themountainsin the southeastern part of theU.S. stateofAlaskaand most of theYukon,Canada. This range has an area of 364,710 km2(140,820 sq mi).[22]

TheCoast Mountainsrun from the lowerFraser Riverand theFraser Canyonnorthwestward, separating theInterior Plateaufrom the Pacific Ocean.[23]Their coastal flank is characterized by an intense network of fjords and associated islands, very similar to theNorwegian coastline,while their inland side against the plateau they transition to the high plateau in dryland valleys notable for a series of large lakes similar to the alpine lakes of southern Switzerland, beginning in deep mountains and ending in flatland. They are subdivided in three main groupings, thePacific Rangesbetween the Fraser andBella Coola,theKitimat Rangesfrom there northwards to theNass Riverand theBoundary Rangesfrom there to their terminus in theYukonTerritory atChampagne PassandChilkat Passnorthwest ofHaines, Alaska.[23]TheSaint Elias Mountainslie to their west and northwest, while theYukon Rangesand Yukon Basin lie to their north. On the inland side of the Boundary Ranges are theTahltanandTagish Highlandsand also theSkeena Mountains,part of theInterior Mountainssystem, which also extend southwards on the inland side of theKitimat Ranges.[23]

The terrain of the main spine of the Coast Mountains is typified by heavy glaciation, including several very large icefields of varying elevation. Of the three subdivisions, the Pacific Ranges are the highest and are crowned byMount Waddington,while the Boundary Ranges contain the largest icefields, theJuneau Icefieldbeing the largest. The Kitimat Ranges are lower and less glacier-covered than either of the other two groupings, but are extremely rugged and dense.

The Coast Mountains are made ofigneousandmetamorphic rockfrom an episode ofarc volcanismrelated tosubductionof theKulaandFarallon Platesduring theLaramide orogenyabout 100 million years ago.[24]The widespreadgraniteforming the Coast Mountains formed when magma intruded and cooled at depth beneath volcanoes of theCoast Range Arcwhereas the metamorphic formed when intruding magma heated the surrounding rock to produceschist.

TheInsular Mountainsextend fromVancouver Islandin the south toHaida Gwaiiin the north on theBritish Columbia Coast.It contains two main mountain ranges, theVancouver Island Rangeson Vancouver Island and theQueen Charlotte Mountainson Haida Gwaii.[25]

Pacific Border Province in contiguous U.S.

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Olympic Mountainsin Washington

TheOlympic Mountainsis amountain rangeon theOlympic Peninsulaof westernWashingtonin theUnited States.Themountains,part of thePacific Coast Ranges,are not especially high –Mount Olympusis the highest at 7,962 ft (2,427 m) – but the western slopes of the Olympics rise directly out of thePacific Oceanand are the wettest place in the 48 contiguous states.[26][27]Most of the mountains are protected within the bounds of theOlympic National Park.

TheOregon Coast Rangeis the part of the Coast Range system that is denoted as between the mouth of theColumbia Riverand theMiddle Fork Coquille River.It is about 200 miles (320 km) long. The highest peak isMarys Peak,at 4,101 ft (1,250 m).

TheCalifornia Coast Rangesare one of the eleven traditional geomorphic provinces of California. This province includes several – but not all – mountain ranges along the California coast (the Transverse Ranges, Peninsular Ranges and the Klamath Mountains are not included).[28]

Western mountain ranges of Mexico

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TheSierra Madre del Surmountains in southwestern Mexico form a southern extension of thePeninsular RangesofBaja California.[19]The Peninsular Ranges are separated from the Sierra Madre del Sur by an expanse of ocean.

Nevadan belt

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The Nevadan belt is located between the Pacific coast belt and the Laramide belt.Nevadameans "snow-covered" in Spanish.

Interior System of Canada

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In Canada, theNorthern Interior Mountainsare a northern extension of the Columbia Mountains.[29]They include theHazelton Mountains,Cassiar Mountains,Omineca Mountains,andSkeena Mountains.

Location map of Columbia Mountains
Monashee Mountains

TheColumbia Mountainsare a designation in British Columbia for a group of four ranges lying between theRocky Mountain Trench(to the east) and theInterior Plateau(to the west). These ranges are theCariboo Mountains,which are the northernmost and sometimes considered to be part of the Interior Plateau, theSelkirk Mountains,thePurcell Mountains,and theMonashee Mountains.

The Columbia Mountains are classified as being in Canada's interior system, rather than its eastern system.[30]However, the Columbia Mountains are an extension of mountains in the United States that are considered part of the Rocky Mountains, and therefore the Columbia Mountains are often treated as being part of the Rockies.[31]

The Selkirks and Purcells lie entirely within the basin of the Columbia River, while the Monashees lie to the river's west on its southward course from itsBig Bendand are flanked on the west by the basin of theThompsonandOkanagan Rivers.There are many named subranges of all four subgroupings, particularly in the Selkirks and Monashees. The southward extension of the Selkirks, Purcells and Monashees into the United States are reckoned to be part of theRocky Mountainsand the designation Columbia Mountains is not used there (the Purcells, also, go by the name "Percell Mountains" in the United States). TheSalishandCabinet Mountainssouth of theKootenai Riverare essentially part of the same landform, but are officially designated part of the Rocky Mountains in the United States.

To the west of the Monashees and Cariboos, there are three intermediary upland areas which are transitional between the mountain ranges and the plateaus flanking theFraserandThompson Rivers.These – theQuesnel,ShuswapandOkanagan Highlands,are sometimes considered as being part of the neighbouring ranges rather than the plateaus and are often spoken of that way locally but are formally designated as being part of theInterior Plateau.The southernmost extends into the Washington, where it is named by the American spelling Okanogan Highland (and was the first-named of these groupings).[30]

Cascade–Sierra Mountains in contiguous U.S.

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TheCascade Range(called theCascade Mountainsin Canada) extends fromnorthern Californiain the United States toBritish Columbia,Canada. It consists of non-volcanic andvolcanicmountains: all of the known historic eruptions in the contiguous United States have been from thevolcanoes of the Cascade Volcanic Arc.The highest peak in the Cascade Range isMount Rainier(14,409 feet (4,392 m)), astratovolcano.The small portion of the Cascade Range in Canada is called the Cascade Mountains or Canadian Cascades, and in its southwestern area is similar in terrain to the area north ofGlacier Peak,known as theNorth Cascades,and its northern and eastern extremities verge on theThompson Plateauin a less rugged fashion than in most other parts of the range. The North Cascades are very different in character from the series of high volcanic stratovolcanoes from Rainier southwards toMount ShastaandLassen Peak,and are more severely alpine and steeply rugged, particularly theSkagit Range.Inland portions of the range are dryland and plateau-like in character, e.g. theOkanagan Range,which lies along the Cascades' northeastern margin, separated by theSimilkameen River.

TheSierra Nevadaforms an inland mountain spine of northern California, extending from the terminus of theCascade Rangesouth ofLassen Peaksouthwards along the east flank of theCentral Valley of Californiato theTransverse Ranges,forming a mountain region of complex terrain and varied geology which separates the Central Valley from theGreat Basinto the east. The mean height of the mountain summits in the Sierra Nevada gradually increases from north to south, culminating atMount Whitney(14,505 feet (4,421 m)), the highest point in thecontiguous United States.From east to west, the Sierra is wedge-shaped: the west slope gradually rises and the east slope forms a steepescarpment,particularly so in the southern portion.

The northern Sierra surface rocks are predominantly volcanic, while the southern Sierra graniticbatholithhas been sculpted by glaciers into dramaticU-shaped valleysand thin ridges calledarêtes.

Sierra Madre Occidental in Mexico

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TheSierra Madre Occidentalmountain range is a southern extension of the Sierra Nevada.[32]The range extends from near the Arizona border down to the Sierra Madre del Sur, along the western mainland of Mexico. The high plateau that is formed by the range is cut by deep river valleys.

Laramide Belt

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TheLaramidebelt is on the side of the North American Cordillera most distant from the Pacific Coast Ranges. It is named for theLaramie Mountainsof easternWyoming(in turn named forJacques La Ramee,a trapper who disappeared in the Laramie Mountains in 1820 and was never heard from again).[33]

Alaska and Eastern System of Canada

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The Brooks Range in Alaska

TheBrooks Rangeincludes the northernmost of the major mountain systems of the North American Cordillera, and extends along an east–west axis across northernAlaskafrom near the northern opening of theBering Straitto the northernYukonTerritory. Major subranges include theBritish MountainsandRichardson Mountains,towards their eastern end, and at their farthest west is the small subrange thatDe Long Mountains.The Brooks Range forms the northern flank of the lowerYukon Riverbasin, separating it from Alaska'sNorth Sloperegion, facing theBeaufort Sea.The Brooks Range is considered part of (or an extension of) theRockies.[34][35][36]South of the Brooks Range are theMackenzie Mountains,and theCanadian Rockies.

Rocky Mountain System in contiguous U.S.

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In theRocky Mountains,the highest peak isMount ElbertinColoradoat 14,439 feet (4,401 m) above sea level. The American Rockies rise steeply over theInterior Plainsto the east, and over theGreat Basinto the west, and extend south to theRio Grandein New Mexico. The United States definition of the Rockies includes theCabinetandSalish Mountainsof Idaho and Montana, whereas their counterparts north of theKootenai River,theColumbia Mountains,are sometimes considered a separate system lying to the west of the hugeRocky Mountain Trenchwhich runs the length of British Columbia.[31]

Sierra Madre Oriental in Mexico

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TheSierra Madre Orientalmountains in eastern Mexico are a southern extension of theRocky Mountains.[36][37]The Sierra Madre Oriental spans about 1,000 km (600 miles). Mexico's Gulf Coastal Plain lies to the east of the range, between the mountains and the Gulf of Mexico coast. The Mexican Plateau lies to the west of the range.

Intermontane areas seaward from the Nevadan belt

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The Nevadan belt runs down the middle of the North American Cordillera. Therefore, the intermontane areas can be divided up into the areas east of the Nevadan belt, and those west of the Nevadan belt.

Canadian portion

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Interior Plateau
Shuswap Highland

TheInterior Plateauis the northern continuation of theColumbia Plateau,and covers much of inlandBritish Columbia.TheCariboo MountainsandMonashee Mountainslie to the east, theCanadian Cascadesare to the southwest, and theHazelton MountainsandCoast Rangeto the west and northwest.[38]

Within the Interior plateau, theShuswap Highlandconsists of a portion of the foothills between theThompson PlateauandBonaparte Plateauon the west, and theMonashee MountainsandCariboo Mountainson the east and northeast.[39]

Thompson Plateau
Okanagan Highland

Also within the Interior plateau, theThompson Plateauforms the southern portion of the Interior Plateau. It is bordered on the south by theCanadian Cascadesand on the north by theThompson River.[40]

The Okanagan Highland is the part of the Interior Plateau to the east of the Thompson Plateau, and is bounded by theOkanagan Riveron the west, theShuswap Riveron the north, and theKettle Riveron the east side. The Okanagan Highland is described as being a hilly plateau, and is located in southernBritish Columbiaand northernWashington.[41]The Interior Plateau also includes theQuesnel Highland,Fraser Plateau,Nechako Plateau,andMcGregor Plateau.

Portion in contiguous U.S.

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California'sCentral Valleyis a large, flat valley that dominates the central portion ofCalifornia,stretching inland and parallel to thePacific Oceancoast. Its northern half is referred to as theSacramento Valley,and its southern half as theSan Joaquin Valley.The two-halves meet at the hugeSacramento-San Joaquin River Deltaof the Sacramento and San Joaquin Rivers, which along with their tributaries drain the majority of the valley and flow intoSan Francisco Bay.The Central Valley covers an area of approximately 22,500 square miles (58,000 km2), making it slightly smaller than the state ofWest Virginiaand about 13.7% of California's total area. The Central Valley is 40 to 60 miles (60 to 100 km) wide, with theSierra Nevadato the east and theCoast Rangesto the west.

In northwestern Oregon, the fertileWillamette Valleylies between theOregon Coast Rangeand theCascades;this depression continues north into Washington as thePuget Trough.

Mexican portion

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TheGulf of Californiais a body of water that separates thePeninsular Rangesfrom theSierra Madre Occidentalon theMexicanmainland. The Gulf of California is 1,126 km (700 miles) long and 48 to 241 km (30 to 150 miles) wide, with an area of 177,000 km2(68,000 sq mi), a mean depth of 818.08 m (2,684.0 ft), and a volume of 145,000 km3(35,000 cu mi).[42]

Intermontane areas inland from the Nevadan belt

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Canadian portion

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TheRocky Mountain Trenchis a large valley that extends approximately 1,600 km (990 mi) fromFlathead Lake,Montana,to theLiard River,just south of theBritish ColumbiaYukonborder nearWatson Lake, Yukon.The trench bottom is 3 to 16 km (2 to 10 miles) wide and ranges from 600 to 900 m (2,000 to 3,000 ft) above sea level. The general orientation of the Trench is almost uniformly pointing north. Some of itstopographyhas been carved intoglacial valleys,but it is primarily a byproduct offaulting.The Trench separates theRocky Mountainson its east from theColumbia Mountainsand theCassiar Mountainson its west. It is up to 25 km (16 miles) wide, if measured peak-to-peak.

For convenience the Rocky Mountain Trench may be divided into northern and southern sections. The dividing point reflects the separation of north and easterly flows to the Arctic Ocean versus south and westerly flows to the Pacific Ocean. A break in the valley system at around 54°N nearPrince George,British Columbiamay be used for this purpose. There are three main mountain ranges in the Canadian area named the Rocky Mountains, the Columbia Mountains, and the Coast Mountains.

Portion in contiguous U.S.

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Colorado Plateau
Basin & Range Province (indicated in blue)

TheColumbia Plateauis ageologicandgeographicregion that lies across parts of theU.S. statesofWashington,Oregon,andIdaho.[43]It is a wideflood basaltplateau between theCascade Rangeand theRocky Mountains,cut through by theColumbia River.In one of various usages, the term "Columbia Basin"refers to more or less the same area as the Columbia Plateau.[44]

TheBasin and Range provincecovers most of the state ofNevadaand parts of the states ofArizona,California,Idaho,New Mexico,Oregon,Texas,Utah,andWyoming,as well as much of northernMexico.It is an extremely arid region characterized bybasin and rangetopography.[45]

TheColorado Plateauis an area of high desert located inArizona,New Mexico,Colorado,andUtah,bisected by theColorado Riverwhich flows westward through the southern part, and theGreen Riverwhich flows south from the northernmost part of the plateau. The Green is a tributary of the Colorado, the confluence being west of Moab, Utah in Canyonlands National Park.[46]

Mexican portion

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TheMexican Plateauis one of six distinct physiographic sections of theBasin and Range Province,which in turn is part of theIntermontane Plateausphysiographic division. It is a large arid-to-semiaridplateauthat occupies much of northern and centralMexico.Averaging 1,825 m (5,988 ft) above sea level, it extends from theUnited States borderin the north to theTrans-Mexican Volcanic Beltin the south and is bounded by theSierra Madre OccidentalandSierra Madre Orientalto the west and east, respectively.

A low east–west mountain range in the state ofZacatecasdivides the plateau into northern and southern sections. These two sections, called the Northern Plateau (Spanish:Mesa del Norte) and Central Plateau (Spanish:Mesa Central), are now generally regarded by geographers as sections of one plateau.

See also

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References

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  1. ^R. Saager & F. Bianconi (1971). "The Mount Nansen gold–silver deposit, Yukon territory, Canada".Mineralium Deposita.6(3).doi:10.1007/BF00208030.S2CID129092271.
  2. ^D. S. Cowan (1985). "Structural styles in Mesozoic and Cenozoic melanges in the Western Cordillera of North America".Geological Society of America Bulletin.96(4): 451.doi:10.1130/0016-7606(1985)96<451:SSIMAC>2.0.CO;2.
  3. ^abMelanie Ostopowich (2005)The Cordillera,Weigl Educational Publishers Limited,ISBN1553881494,pp. 6, 12, and 20: "The Cordillera is one of the seven geographic regions in Canada".
  4. ^The Encyclopedia Americana: a library of universal knowledge,Encyclopedia Americana Corp., 1918,ISBN0717201333,p. 687: "[N]ame from the Spanish....It is used particularly in physical geography, although in geology also it is sometimes applied...."
  5. ^abFrank Pressand Raymond SieverEarth,pp. 534–535, Macmillan, 1986.
  6. ^A. J. Eardley (1967)."Western Cordillera—Alaska to Mexico: ABSTRACT".AAPG Bulletin.51(9): 1900–1901.doi:10.1306/5d25c1b1-16c1-11d7-8645000102c1865d.
  7. ^T. O. Tobisch; S. R. Paterson; S. Longiaru; T. Bhattacharyya (1987). "Extent of the Nevadan orogeny, central Sierra Nevada, California".Geology.15(2): 132.doi:10.1130/0091-7613(1987)15<132:EOTNOC>2.0.CO;2.
  8. ^P. J. Coney & T. A. Harms (1984)."Cordilleran metamorphic core complexes: Cenozoic extensional relics of Mesozoic compression"(PDF).Geology.12(9): 550.doi:10.1130/0091-7613(1984)12<550:CMCCCE>2.0.CO;2.S2CID129399334.Archived fromthe original(PDF)on June 12, 2011.RetrievedMay 7,2011.
  9. ^M. E. McMillan; P. L. Heller & S. L. Wing (2006)."History and causes of post-Laramide relief in the Rocky Mountain orogenic plateau"(PDF).Geological Society of America Bulletin.118(3–4): 393.doi:10.1130/B25712.1.Archived fromthe original(PDF)on June 23, 2010.RetrievedMarch 28,2013.
  10. ^W. R. Dickinson; M. A. Klute; M. J. Hayes; S. U. Janecke; E. R. Lundin; M. A. McKittrick & M. D. Olivares (1988). "Paleogeographic and paleotectonic setting of Laramide sedimentary basins in the central Rocky Mountain region".Geological Society of America Bulletin.100(7): 1023.doi:10.1130/0016-7606(1988)100<1023:PAPSOL>2.3.CO;2.
  11. ^J. A. Wolfe; C. E. Forest & P. Molnar (1998). "Paleobotanical evidence of Eocene and Oligocene paleoaltitudes in midlatitude western North America".Geological Society of America Bulletin.110(5): 664.doi:10.1130/0016-7606(1998)110<0664:PEOEAO>2.3.CO;2.
  12. ^D. Alt and D. Hyndman. (1995). Northwest Exposures: A Geological Story of the North West. Mountain Press Publishing Company, Missoula, Montana
  13. ^S. Brunsfeld, J. Sullivan, D. Soltis, and P. Sotis (2001)."Comparative phylogeography of north-western north america: A synthesis".In: Silverton, J., Antonovics, J. (Eds.),Integrating Ecology and Evolution in a Spatial Context.The 14th Special Symposium of the British Ecological Society. British Ecolological Society, Blackwell Science Ltd., Ch. 15, pp. 319–339.
  14. ^The Geography of Alaska: Physical Geography,Alaska Humanities Forum: "At a very general level, Alaska is part of four general physiographic regions, the Interior Plains, Rocky Mountains, Intermontane Basins and Ranges, and the Pacific Mountains and Valleys".
  15. ^Wheeler, J. and Kostbade, J.World Regional Geography(Saunders College Publishing 1990): "The mainland ranges of the panhandle are a northward extension of the cascade range and the British Columbia Coastal ranges, while the mountainous offshore islands are an extension of the Coast Ranges of the Pacific Northwest and the islands of British Columbia."
  16. ^William Bailey et al.The surface climates of Canada,McGill–Queen's Press – MQUP, 1997, p. 226.
  17. ^abMerriam-Webster's Geographical Dictionary,Merriam-Webster, 1997, pp. 219 and 1087,ISBN0877795460
  18. ^Shatrughna Sinha and Faguni Ram (1993)Instant Encyclopaedia of Geography,Mittal Publications, p. 140,ISBN8170994896
  19. ^abEncyclopedia Americana: the International Reference Work,Volume 18: "Sierra Madre del Sur. — This sierra, which crosses the states of Colima, Michoacan, Guerrero, and Oaxaca, is the continuation of the Sierra de Baja California and the other mountain ranges linked with it." (Americana Corporation 1961).
  20. ^Hultén, Eric.Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants,p. xiv (Stanford University Press, 1968).
  21. ^Stefoff, Rebecca.Alaska,p. 14 (Marshall Cavendish, 2006).
  22. ^Yukon Rangesin the Canadian Mountain Encyclopedia
  23. ^abcWilson, Robert J.Geology and Economic Minerals of Canada,p. 26 (Geological Survey of Canada, Department of Energy, Mines and Resources, 1976).
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  29. ^Parsons, M. and Quinn, O. "Insular and Coastal Mountains, Interior MountainsArchivedOctober 10, 2012, at theWayback Machine",Canadian Ministry of Environment:" Interior Mountains comprising the Columbia Mountains of the southern interior and the Omineca, Cassiar, Skeena and Hazelton Mountains of the northern interior. "
  30. ^abS. Holland,Landforms of British ColumbiaArchivedMarch 4, 2016, at theWayback Machine,BC Govt, 1976
  31. ^abRichard Cannings (2007).The Rockies: A Natural History.Greystone/David Suzuki Foundation. p. 5.ISBN9781553652854.
  32. ^Merrill, Tim et al.Mexico: A Country Study,p. 80 (Library of Congress, Federal Research Division, Claitors Pub Div. 2005): "The Sierra Madre Occidental on the west is a continuation of California's Sierra Nevada (with a break in southeastern California and extreme northern Mexico)…."
  33. ^Thiem, Jon.Rabbit Creek Country: Three Ranching Lives in the Heart of the Mountain West,p. 143 (UNM Press, 2008).
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  35. ^William Safire.The New York Times guide to essential knowledge: a desk reference for the curious mind,Macmillan, 2007, p. 623,ISBN0312376596.
  36. ^abEdwin Bridges.World Geomorphology,Cambridge University Press, 1990, p. 88,ISBN0521289653.
  37. ^"Sierra Madre Oriental",Encyclopædia Britannica Online(2011).
  38. ^Interior Plateau[permanent dead link]in the BCGNIS(British Columbia Geographic Names Information System)
  39. ^Shuswap Highland[permanent dead link]in the BCGNIS(British Columbia Geographic Names Information System)
  40. ^Thompson Plateau[permanent dead link]in the BCGNIS(British Columbia Geographic Names Information System)
  41. ^Okanagan Highland[permanent dead link]in the BCGNIS(British Columbia Geographic Names Information System)
  42. ^Rebekah K. Nix."The Gulf of California: A Physical, Geological, and Biological Study"(PDF).University of Texas at Dallas.RetrievedApril 10,2010.
  43. ^"Columbia Plateau".Geographic Names Information System.United States Geological Survey,United States Department of the Interior.
  44. ^Ben Floyd, et al. "GlossaryArchivedMarch 22, 2005, at theWayback Machine".(1998)Hanford Reach Protection and Management Program Interim Action PlanArchivedSeptember 27, 2007, at theWayback Machine.Prosser, Washington: Benton County Planning Department.
  45. ^"Boundary Descriptions and Names of Regions, Subregions, Accounting Units and Cataloging Units".U.S. Geological Survey.RetrievedOctober 23,2010.
  46. ^"Colorado Plateau".Geographic Names Information System.United States Geological Survey.
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