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The North American Cordillera, sometimes also called the Western Cordillera of North America, the Western Cordillera or the Pacific Cordillera, is the
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...
n portion of the
American Cordillera The American Cordillera is a chain of mountain ranges ( cordilleras) that consists of an almost continuous sequence of mountain ranges that form the western "backbone" of North America, Central America and South America, with Aconcagua as the ...
, the mountain chain system (
cordillera A cordillera is an extensive chain and/or network system of mountain ranges, such as those in the west coast of the Americas. The term is borrowed from Spanish, where the word comes from , a diminutive of ('rope'). The term is most commonly us ...
) along the western coast ( Pacific coast) of the
Americas The Americas, which are sometimes collectively called America, are a landmass comprising the totality of North America, North and South America. The Americas make up most of the land in Earth's Western Hemisphere and comprise the New World. ...
. The North American Cordillera covers an extensive area of
mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have ari ...
s,
intermontane Intermontane is a physiographic adjective formed from the prefix " inter-" (''signifying among, between, amid, during, within, mutual, reciprocal'') and the adjective "montane" (inhabiting, or growing in mountainous regions, especially cool, moi ...
basins Basin may refer to: Geography and geology * Depression (geology) ** Back-arc basin, a submarine feature associated with island arcs and subduction zones ** Debris basin, designed to prevent damage from debris flow ** Drainage basin (hydrology), a ...
and
plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ...
s in Western/ Northwestern Canada,
Western United States The Western United States (also called the American West, the Far West, and the West) is the region comprising the westernmost states of the United States. As American settlement in the U.S. expanded westward, the meaning of the term ''the We ...
and
Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
, including much of the territory west of the
Great Plains The Great Plains (french: Grandes Plaines), sometimes simply "the Plains", is a broad expanse of flatland in North America. It is located west of the Mississippi River and east of the Rocky Mountains, much of it covered in prairie, steppe, a ...
. 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 of
physical geography Physical geography (also known as physiography) is one of the three main branches of geography. Physical geography is the branch of natural science which deals with the processes and patterns in the natural environment such as the atmosphere ...
.Melanie Ostopowich (2005)
The Cordillera
',
Weigl Educational Publishers Limited Weigl Educational Publishers Limited is a publishing house in Canada, one of the country's largest. Linda A. Weigl founded the company in 1979 as a textbook publisher. First based in Saskatchewan, the company moved to Alberta in 1984, and now h ...
, , pp. 6, 12, and 20: "The Cordillera is one of the seven geographic regions in Canada".


Major features

The North American Cordillera extends from the U.S. state of
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
to the southern border of
Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
, and includes some of the highest peaks on the continent.
Frank Press Frank Press (December 4, 1924 – January 29, 2020) was an American geophysicist. He was an advisor to four U.S. presidents, and later served two consecutive terms as president of the U.S. National Academy of Sciences (1981–1993). He was the au ...
and Raymond Siever
Earth
', pp. 534–535, Macmillan, 1986.
Its mountain ranges generally run north to south along three main belts: the Pacific Coast Ranges in the west, the Nevadan belt in the middle (including the Sierra Nevada), and the Laramide belt in the east (including the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
). These three orogenic belts (also called "orogens") arose due to the engagement of
tectonic plates Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large ...
which deformed the Earth's lithosphere (crust and uppermost mantle). For example, the
Laramide orogeny The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the ...
changed the
topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sc ...
of the central Rocky Mountains and adjoining Laramide regions (from central Montana to central New Mexico) during the
Late Cretaceous The Late Cretaceous (100.5–66 Ma) is the younger of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', ...
80 million years ago. Prior to this time the Rocky Mountain region was occupied by a broad basin. Further topographical evolution occurred during the
Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...
(55–50 million years ago) and
Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but t ...
(34–23 million years ago), but since that time the region has been relatively stable.D. Alt and D. Hyndman. (1995). Northwest Exposures: A Geological Story of the North West. Mountain Press Publishing Company, Missoula, MontanaS. 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.
Generally speaking, it will be convenient here to consider these three belts going west to east, and north to south. In
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
, 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. In the Alaska panhandle, the mainland mountain ranges and offshore islands (the
Alexander Archipelago The Alexander Archipelago (russian: Архипелаг Александра) is a long archipelago (group of islands) in North America lying off the southeastern coast of Alaska. It contains about 1,100 islands, the tops of submerged coastal m ...
) are extensions of respective ranges further south. In Canada, the North American Cordillera is usually divided into three physiographic regions: the western system, the interior system, and the eastern system. The western system includes the Coast Mountains, the interior system includes the
Columbia Mountains The Columbia Mountains are a group of mountain ranges along the upper Columbia River in British Columbia, Montana, Idaho and Washington. The mountain range covers 135,952 km² (52,491 sq mi). The range is bounded by the Rocky Mountain T ...
, and the eastern system includes the Canadian Rockies. At its midsection between
San Francisco San Francisco (; Spanish for " Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the fourth most populous in California and 17t ...
,
California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
and
Denver Denver () is a consolidated city and county, the capital, and most populous city of the U.S. state of Colorado. Its population was 715,522 at the 2020 census, a 19.22% increase since 2010. It is the 19th-most populous city in the Unit ...
,
Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...
, the North American Cordillera is about wide, and its physiographic provinces at this midpoint are as follows, going from west to east: the Pacific Coast Ranges, the Central Valley, the Sierra Nevada, the
Basin and Range Province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating ...
(forming many narrow ranges and valleys), the Colorado Plateau, and the Rocky Mountains. In the United States, another major feature of the Cordillera is the
Columbia Plateau The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Col ...
, located north of California between the Cascade Range – which is a northern extension of the Sierra Nevada – and the Rocky Mountains. In Mexico, the
Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...
, and the Sierra Madre Oriental further east, surround the Mexican Plateau.
Merriam-Webster's Geographical Dictionary
', Merriam-Webster, 1997, pp. 219 and 1087,
To the west of the Sierra Madre Occidental, the
Peninsular Ranges The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Coast Ranges, which ...
border the Pacific Ocean, and the Sierra Madre del Sur is the southern extension of the Peninsular Ranges.''Encyclopedia 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). 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

The Pacific Coast Ranges, comprising the Pacific Coast Belt, parallel the North American Pacific Coast, and comprise several mountain systems. Along the
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
and Alaska coast, the mountains intermix with the sea in a complex maze of fjords, with thousands of islands. Off the Southern California coast the
Channel Islands The Channel Islands ( nrf, Îles d'la Manche; french: îles Anglo-Normandes or ''îles de la Manche'') are an archipelago in the English Channel, off the French coast of Normandy. They include two Crown Dependencies: the Bailiwick of Jersey, ...
archipelago An archipelago ( ), sometimes called an island group or island chain, is a chain, cluster, or collection of islands, or sometimes a sea containing a small number of scattered islands. Examples of archipelagos include: the Indonesian Arch ...
of the Santa Monica Mountains extends for .


Southern Alaska ranges

In southern Alaska, the primary mountain ranges are the
Alaska Range The Alaska Range is a relatively narrow, 600-mile-long (950 km) mountain range in the southcentral region of the U.S. state of Alaska, from Lake Clark at its southwest endSources differ as to the exact delineation of the Alaska Range. ThBo ...
, Wrangell Mountains,
Saint Elias Mountains The Saint Elias Mountains (french: Chaîne Saint-Élie) are a subgroup of the Pacific Coast Ranges, located in southeastern Alaska in the United States, Southwestern Yukon and the very far northwestern part of British Columbia in Canada. The r ...
, Kenai Mountains,
Chugach Mountains The Chugach Mountains of southern Alaska are the northernmost of the several mountain ranges that make up the Pacific Coast Ranges of the western edge of North America. The range is about long and wide, and extends from the Knik and Turnaga ...
, and Talkeetna Mountains.


Western System of Canada

The
Yukon Ranges The Yukon Ranges are a mountain range comprising the mountains in the southeastern part of the U.S. state of Alaska and most of the Yukon in Canada. Named after the Yukon, this range has area of .mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher ...
s in the southeastern part of the U.S. state of
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
and most of the
Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
, Canada. This range has an area of . The Coast Mountains run from the lower
Fraser River The Fraser River is the longest river within British Columbia, Canada, rising at Fraser Pass near Blackrock Mountain in the Rocky Mountains and flowing for , into the Strait of Georgia just south of the City of Vancouver. The river's annual ...
and the Fraser Canyon northwestward, separating the Interior Plateau from the Pacific Ocean.Wilson, Robert J. ''Geology and Economic Minerals of Canada'', p. 26 (Geological Survey of Canada, Department of Energy, Mines and Resources, 1976). Their coastal flank is characterized by an intense network of fjords and associated islands, very similar to the Norwegian 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, the
Pacific Ranges , photo = Mount Garibaldi (50997016501).jpg , photo_size = 280px , photo_caption = Mount Garibaldi massif as seen from Squamish , map = , map_image = South BC-NW USA-relief PacificRanges.png , ...
between the Fraser and Bella Coola, the
Kitimat Ranges , photo = Lax Kw'alaams.jpg , photo_size = 280px , photo_caption = Lax Kw'alaams backdropped by Mount McNeil , map = , map_image = BC-relief_Kitimatranges.png , map_caption = Kitimat Range ...
from there northwards to the Nass River and the Boundary Ranges from there to their terminus in the
Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
Territory at Champagne Pass and Chilkat Pass northwest of Haines, Alaska. The
Saint Elias Mountains The Saint Elias Mountains (french: Chaîne Saint-Élie) are a subgroup of the Pacific Coast Ranges, located in southeastern Alaska in the United States, Southwestern Yukon and the very far northwestern part of British Columbia in Canada. The r ...
lie to their west and northwest, while the
Yukon Ranges The Yukon Ranges are a mountain range comprising the mountains in the southeastern part of the U.S. state of Alaska and most of the Yukon in Canada. Named after the Yukon, this range has area of .Tahltan The Tahltan or Nahani are a First Nations people of the Athabaskan-speaking ethnolinguistic group who live in northern British Columbia around Telegraph Creek, Dease Lake, and Iskut. The Tahltan constitute the fourth division of the ''Nahane' ...
and Tagish Highlands and also the Skeena Mountains, part of the
Interior Mountains The Interior Mountains or Northern Interior Mountains are the semi-official names for an expansive collection of mountain ranges that comprises much of the northern half of the Canadian province of British Columbia and a large area of southern Y ...
system, which also extend southwards on the inland side of the
Kitimat Ranges , photo = Lax Kw'alaams.jpg , photo_size = 280px , photo_caption = Lax Kw'alaams backdropped by Mount McNeil , map = , map_image = BC-relief_Kitimatranges.png , map_caption = Kitimat Range ...
. 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 by
Mount Waddington Mount Waddington, once known as Mystery Mountain, is the highest peak in the Coast Mountains of British Columbia, Canada. Although it is lower than Mount Fairweather and Mount Quincy Adams, which straddle the United States border between Ala ...
, while the Boundary Ranges contain the largest icefields, the Juneau Icefield being 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 of
igneous Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rock is formed through the cooling and solidification of magma or ...
and
metamorphic rock Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock (protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...
from an episode of arc volcanism related to
subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, ...
of the Kula and Farallon Plates during the
Laramide orogeny The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the ...
about 100 million years ago. The widespread
granite Granite () is a coarse-grained ( phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies un ...
forming the Coast Mountains formed when magma intruded and cooled at depth beneath volcanoes of the
Coast Range Arc The Coast Range Arc was a large volcanic arc system, extending from northern Washington through British Columbia and the Alaska Panhandle to southwestern Yukon. The Coast Range Arc lies along the western margin of the North American Plate in the ...
whereas the metamorphic formed when intruding magma heated the surrounding rock to produce
schist Schist ( ) is a medium-grained metamorphic rock showing pronounced schistosity. This means that the rock is composed of mineral grains easily seen with a low-power hand lens, oriented in such a way that the rock is easily split into thin flakes ...
. The Insular Mountains extend from
Vancouver Island Vancouver Island is an island in the northeastern Pacific Ocean and part of the Canadian province of British Columbia. The island is in length, in width at its widest point, and in total area, while are of land. The island is the largest by ...
in the south to Haida Gwaii in the north on the British Columbia Coast. It contains two main mountain ranges, the Vancouver Island Ranges on Vancouver Island and the Queen Charlotte Mountains on Haida Gwaii.


Pacific Border Province in contiguous U.S.

The
Olympic Mountains The Olympic Mountains are a mountain range on the Olympic Peninsula of the Pacific Northwest of the United States. The mountains, part of the Pacific Coast Ranges, are not especially high – Mount Olympus is the highest at ; however, the easte ...
is a
mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have ari ...
on the
Olympic Peninsula The Olympic Peninsula is a large arm of land in western Washington that lies across Puget Sound from Seattle, and contains Olympic National Park. It is bounded on the west by the Pacific Ocean, the north by the Strait of Juan de Fuca, a ...
of western
Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...
in the
United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...
. The
mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited summit area, and is usually higher ...
s, part of the Pacific Coast Ranges, are not especially high –
Mount Olympus Mount Olympus (; el, Όλυμπος, Ólympos, also , ) is the highest mountain in Greece. It is part of the Olympus massif near the Thermaic Gulf of the Aegean Sea, located in the Olympus Range on the border between Thessaly and Macedonia, be ...
is the highest at – but the western slopes of the Olympics rise directly out of the
Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...
and are the wettest place in the 48 contiguous states. Most of the mountains are protected within the bounds of the Olympic National Park. The Oregon Coast Range is the part of the Coast Range system that is denoted as between the mouth of the Columbia River and the Middle Fork Coquille River. It is about long. The highest peak is
Marys Peak Marys Peak (formerly Mary's Peak and sometimes still spelled this way) is a mountain in Benton County, Oregon, Benton County, Oregon, United States, just southwest of Philomath, Oregon, Philomath. According to the Benton County Historical Societ ...
, at . The
California Coast Ranges The Coast Ranges of California span from Del Norte or Humboldt County, California, south to Santa Barbara County. The other three coastal California mountain ranges are the Transverse Ranges, Peninsular Ranges and the Klamath Mountains. ...
are 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).


Western mountain ranges of Mexico

The Sierra Madre del Sur mountains in southwestern Mexico form a southern extension of the
Peninsular Ranges The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Coast Ranges, which ...
of
Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...
. The Peninsular Ranges are separated from the Sierra Madre del Sur by an expanse of ocean.


Nevadan belt

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


Interior System of Canada

In Canada, the Northern Interior Mountains are a northern extension of the Columbia Mountains. They include the Hazelton Mountains,
Cassiar Mountains The Cassiar Mountains (french: Chaîne des Cassiars) are the most northerly group of the Northern Interior Mountains in the Canadian province of British Columbia and also extend slightly into the southernmost Yukon Territory. They lie north and ...
, Omineca Mountains, and Skeena Mountains. The
Columbia Mountains The Columbia Mountains are a group of mountain ranges along the upper Columbia River in British Columbia, Montana, Idaho and Washington. The mountain range covers 135,952 km² (52,491 sq mi). The range is bounded by the Rocky Mountain T ...
are a designation in British Columbia for a group of four ranges lying between the Rocky Mountain Trench (to the east) and the Interior Plateau (to the west). These ranges are the Cariboo Mountains, which are the northernmost and sometimes considered to be part of the Interior Plateau, the Selkirk Mountains, the
Purcell Mountains The Purcell Mountains are a mountain range in southeastern British Columbia, Canada. They are a subrange of the Columbia Mountains, which includes the Selkirk, Monashee, and Cariboo Mountains. They are located on the west side of the Rocky Moun ...
, and the Monashee Mountains. The Columbia Mountains are classified as being in Canada's interior system, rather than its eastern system. 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. 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 its Big Bend and are flanked on the west by the basin of the
Thompson Thompson may refer to: People * Thompson (surname) * Thompson M. Scoon (1888–1953), New York politician Places Australia *Thompson Beach, South Australia, a locality Bulgaria * Thompson, Bulgaria, a village in Sofia Province Canada ...
and Okanagan 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 the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
and the designation Columbia Mountains is not used there (the Purcells, also, go by the name "Percell Mountains" in the United States). The Salish and Cabinet Mountains south of the Kootenai River are 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 the Fraser and Thompson Rivers. These – the
Quesnel Quesnel or Quesnell means "little oak" in the Picard language, Picard dialect of French language, French. It is used as a proper name and may refer to: Places * Le Quesnel, a commune the Somme department in France * Quesnel, British Columbia, a c ...
, Shuswap and Okanagan 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 the Interior 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).S. Holland,
Landforms of British Columbia
'', BC Govt, 1976


Cascade–Sierra Mountains in contiguous U.S.

The Cascade Range (called the Cascade Mountains in Canada) extends from northern California in the United States to
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
, Canada. It consists of non-volcanic and
volcanic A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plat ...
mountains: all of the known historic eruptions in the contiguous United States have been from the volcanoes of the Cascade Volcanic Arc. The highest peak in the Cascade Range is Mount Rainier (), a stratovolcano. 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 of Glacier Peak, known as the North Cascades, and its northern and eastern extremities verge on the Thompson Plateau in 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 to
Mount Shasta Mount Shasta ( Shasta: ''Waka-nunee-Tuki-wuki''; Karuk: ''Úytaahkoo'') is a potentially active volcano at the southern end of the Cascade Range in Siskiyou County, California. At an elevation of , it is the second-highest peak in the Cascad ...
and Lassen Peak, and are more severely alpine and steeply rugged, particularly the Skagit Range. Inland portions of the range are dryland and plateau-like in character, e.g. the
Okanagan Range The Okanagan Range or Okanogan Range is a small subrange of the Cascade Range straddling the border between British Columbia and Washington south of the Similkameen River on the inland side of the range. The range is the northeasternmost extremit ...
, which lies along the Cascades' northeastern margin, separated by the
Similkameen River The Similkameen River runs through southern British Columbia, Canada, eventually discharging into the Okanagan River near Oroville, Washington, in the United States. Through the Okanagan River, it drains to the Columbia River. The river is said ...
. The Sierra Nevada forms an inland mountain spine of northern California, extending from the terminus of the Cascade Range south of Lassen Peak southwards along the east flank of the
Central Valley of California The Central Valley is a broad, elongated, flat valley that dominates the interior of California. It is wide and runs approximately from north-northwest to south-southeast, inland from and parallel to the Pacific coast of the state. It cov ...
to the Transverse Ranges, forming a mountain region of complex terrain and varied geology which separates the Central Valley from the
Great Basin The Great Basin is the largest area of contiguous endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California. It is noted fo ...
to the east. The mean height of the mountain summits in the Sierra Nevada gradually increases from north to south, culminating at Mount Whitney (), the highest point in the contiguous United States. From east to west, the Sierra is wedge-shaped: the west slope gradually rises and the east slope forms a steep
escarpment An escarpment is a steep slope or long cliff that forms as a result of faulting or erosion and separates two relatively level areas having different elevations. The terms ''scarp'' and ''scarp face'' are often used interchangeably with ''esca ...
, particularly so in the southern portion. The northern Sierra surface rocks are predominantly volcanic, while the southern Sierra granitic
batholith A batholith () is a large mass of intrusive igneous rock (also called plutonic rock), larger than in area, that forms from cooled magma deep in Earth's crust. Batholiths are almost always made mostly of felsic or intermediate rock types, s ...
has been sculpted by glaciers into dramatic U-shaped valleys and thin ridges called arêtes.


Sierra Madre Occidental in Mexico

The
Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...
mountain range is a southern extension of the Sierra Nevada. 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

The
Laramide The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the o ...
belt is on the side of the North American Cordillera most distant from the Pacific Coast Ranges. It is named for the Laramie Mountains of eastern
Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to t ...
(in turn named for Jacques La Ramee, a trapper who disappeared in the Laramie Mountains in 1820 and was never heard from again).


Alaska and Eastern System of Canada

The
Brooks Range The Brooks Range ( Gwich'in: ''Gwazhał'') is a mountain range in far northern North America stretching some from west to east across northern Alaska into Canada's Yukon Territory. Reaching a peak elevation of on Mount Isto, the range is b ...
includes the northernmost of the major mountain systems of the North American Cordillera, and extends along an east–west axis across northern
Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...
from near the northern opening of the Bering Strait to the northern
Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
Territory. Major subranges include the British Mountains and Richardson Mountains, towards their eastern end, and at their farthest west is the small subrange that De Long Mountains. The Brooks Range forms the northern flank of the lower Yukon River basin, separating it from Alaska's
North Slope North Slope can refer to: * Alaska North Slope, a region encompassing the northernmost part of the U.S. state of Alaska * North Slope Borough, Alaska, a borough in Alaska whose boundaries roughly coincide with that of the region * North Slope, Taco ...
region, facing the Beaufort Sea. The Brooks Range is considered part of (or an extension of) the Rockies. South of the Brooks Range are the
Mackenzie Mountains The Mackenzie Mountains are a Canadian mountain range forming part of the Yukon- Northwest Territories boundary between the Liard and Peel rivers. The range is named in honour of Canada's second prime minister, Alexander Mackenzie. Nahanni ...
, and the Canadian Rockies.


Rocky Mountain System in contiguous U.S.

In the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
, the highest peak is Mount Elbert in
Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...
at above sea level. The American Rockies rise steeply over the
Interior Plains The Interior Plains is a vast physiographic region that spreads across the Laurentian craton of central North America, extending along the east flank of the Rocky Mountains from the Gulf Coast region to the Arctic Beaufort Sea. In Canada, it e ...
to the east, and over the
Great Basin The Great Basin is the largest area of contiguous endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California. It is noted fo ...
to the west, and extend south to the Rio Grande in New Mexico. The United States definition of the Rockies includes the
Cabinet Cabinet or The Cabinet may refer to: Furniture * Cabinetry, a box-shaped piece of furniture with doors and/or drawers * Display cabinet, a piece of furniture with one or more transparent glass sheets or transparent polycarbonate sheets * Filin ...
and Salish Mountains of Idaho and Montana, whereas their counterparts north of the Kootenai River, the
Columbia Mountains The Columbia Mountains are a group of mountain ranges along the upper Columbia River in British Columbia, Montana, Idaho and Washington. The mountain range covers 135,952 km² (52,491 sq mi). The range is bounded by the Rocky Mountain T ...
, are sometimes considered a separate system lying to the west of the huge Rocky Mountain Trench which runs the length of British Columbia.


Sierra Madre Oriental in Mexico

The Sierra Madre Oriental mountains in eastern Mexico are a southern extension of the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
.Edwin Bridges.
World Geomorphology
', Cambridge University Press, 1990, p. 88, .
The Sierra Madre Oriental spans about . 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

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

The Interior Plateau is the northern continuation of the
Columbia Plateau The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Col ...
, and covers much of inland
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
. The Cariboo Mountains and Monashee Mountains lie to the east, the Canadian Cascades are to the southwest, and the Hazelton Mountains and Coast Range to the west and northwest. Within the Interior plateau, the
Shuswap Highland The Shuswap Highland is a plateau-like hilly area of in British Columbia, Canada. It spans the upland area between the Bonaparte and Thompson Plateaus from the area of Mahood Lake, at the southeast corner of the Cariboo Plateau, southeast towar ...
consists of a portion of the foothills between the Thompson Plateau and
Bonaparte Plateau The Bonaparte Plateau, in British Columbia, Canada, is a sub-plateau of the Thompson Plateau which extends to the Quesnel River and lies between the Cariboo Mountains on the east and the Fraser River on the west. The Thompson Plateau is itself a ...
on the west, and the Monashee Mountains and Cariboo Mountains on the east and northeast. Also within the Interior plateau, the Thompson Plateau forms the southern portion of the Interior Plateau. It is bordered on the south by the Canadian Cascades and on the north by the Thompson River. The Okanagan Highland is the part of the Interior Plateau to the east of the Thompson Plateau, and is bounded by the Okanagan River on the west, the
Shuswap River The basin of the Shuswap River (pronounced /ˈʃuːʃwɑːp/) lies northeast of the Okanagan Valley in British Columbia, originating in the central Monashee Mountains. It is the upper part of the drainage better known to British Columbians as be ...
on the north, and the Kettle River on the east side. The Okanagan Highland is described as being a hilly plateau, and is located in southern
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
and northern
Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...
. The Interior Plateau also includes the Quesnel Highland,
Fraser Plateau The Fraser Plateau is an intermontane plateau. It is one of the main subdivisions of the Interior Plateau located in the Central Interior of British Columbia. Geography The region includes the Cariboo Plateau and Chilcotin Plateau, and the adjoi ...
, Nechako Plateau, and McGregor Plateau.


Portion in contiguous U.S.

California's Central Valley is a large, flat valley that dominates the central portion of
California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
, stretching inland and parallel to the
Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the conti ...
coast. Its northern half is referred to as the Sacramento Valley, and its southern half as the
San Joaquin Valley The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven ...
. The two-halves meet at the huge Sacramento-San Joaquin River Delta of the Sacramento and San Joaquin Rivers, which along with their tributaries drain the majority of the valley and flow into
San Francisco Bay San Francisco Bay is a large tidal estuary in the U.S. state of California, and gives its name to the San Francisco Bay Area. It is dominated by the big cities of San Francisco, San Jose, and Oakland. San Francisco Bay drains water f ...
. The Central Valley covers an area of approximately , making it slightly smaller than the state of
West Virginia West Virginia is a state in the Appalachian, Mid-Atlantic and Southeastern regions of the United States.The Census Bureau and the Association of American Geographers classify West Virginia as part of the Southern United States while the ...
and about 13.7% of California's total area. The Central Valley is wide, with the Sierra Nevada to the east and the
Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although ...
to the west. In northwestern Oregon, the fertile Willamette Valley lies between the Oregon Coast Range and the Cascades; this depression continues north into Washington as the
Puget Trough The Puget Sound region is a coastal area of the Pacific Northwest in the U.S. state of Washington, including Puget Sound, the Puget Sound lowlands, and the surrounding region roughly west of the Cascade Range and east of the Olympic Mountain ...
.


Mexican portion

The
Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...
is a body of water that separates the
Peninsular Ranges The Peninsular Ranges (also called the Lower California province) are a group of mountain ranges that stretch from Southern California to the southern tip of the Baja California peninsula; they are part of the North American Coast Ranges, which ...
from the
Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...
on the Mexican mainland. The Gulf of California is long and wide, with an area of , a mean depth of , and a volume of .


Intermontane areas inland from the Nevadan belt


Canadian portion

The Rocky Mountain Trench is a large valley that extends approximately from Flathead Lake,
Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...
, to the Liard River, just south of the
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
Yukon Yukon (; ; formerly called Yukon Territory and also referred to as the Yukon) is the smallest and westernmost of Canada's three territories. It also is the second-least populated province or territory in Canada, with a population of 43,964 as ...
border near Watson Lake, Yukon. The trench bottom is wide and ranges from above sea level. The general orientation of the Trench is almost uniformly pointing north. Some of its
topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sc ...
has been carved into
glacial valley U-shaped valleys, also called trough valleys or glacial troughs, are formed by the process of glaciation. They are characteristic of mountain glaciation in particular. They have a characteristic U shape in cross-section, with steep, straight s ...
s, but it is primarily a byproduct of faulting. The Trench separates the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
on its east from the
Columbia Mountains The Columbia Mountains are a group of mountain ranges along the upper Columbia River in British Columbia, Montana, Idaho and Washington. The mountain range covers 135,952 km² (52,491 sq mi). The range is bounded by the Rocky Mountain T ...
and the
Cassiar Mountains The Cassiar Mountains (french: Chaîne des Cassiars) are the most northerly group of the Northern Interior Mountains in the Canadian province of British Columbia and also extend slightly into the southernmost Yukon Territory. They lie north and ...
on its west. It is up to 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 near Prince George,
British Columbia British Columbia (commonly abbreviated as BC) is the westernmost province of Canada, situated between the Pacific Ocean and the Rocky Mountains. It has a diverse geography, with rugged landscapes that include rocky coastlines, sandy beaches, for ...
may 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.

The
Columbia Plateau The Columbia Plateau is a geologic and geographic region that lies across parts of the U.S. states of Washington, Oregon, and Idaho. It is a wide flood basalt plateau between the Cascade Range and the Rocky Mountains, cut through by the Col ...
is a geologic and
geographic Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, a ...
region that lies across parts of the U.S. states of
Washington Washington commonly refers to: * Washington (state), United States * Washington, D.C., the capital of the United States ** A metonym for the federal government of the United States ** Washington metropolitan area, the metropolitan area centered o ...
,
Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
, and
Idaho Idaho ( ) is a U.S. state, state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Monta ...
. It is a wide flood basalt plateau between the Cascade Range and the
Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico ...
, cut through by the Columbia River. In one of various usages, the term " Columbia Basin" refers to more or less the same area as the Columbia Plateau. The
Basin and Range province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating ...
covers most of the state of
Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...
and parts of the states of
Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
,
California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...
,
Idaho Idaho ( ) is a U.S. state, state in the Pacific Northwest region of the Western United States. To the north, it shares a small portion of the Canada–United States border with the province of British Columbia. It borders the states of Monta ...
,
New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...
,
Oregon Oregon () is a U.S. state, state in the Pacific Northwest region of the Western United States. The Columbia River delineates much of Oregon's northern boundary with Washington (state), Washington, while the Snake River delineates much of it ...
,
Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
,
Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...
, and
Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to t ...
, as well as much of northern
Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
. It is an extremely arid region characterized by basin and range topography. The Colorado Plateau is an area of high desert located in
Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...
,
New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe, New Mexico, Santa Fe , LargestCity = Albuquerque, New Mexico, Albuquerque , LargestMetro = Albuquerque metropolitan area, Tiguex , Offi ...
,
Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the ...
, and
Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to its ...
, bisected by the
Colorado River The Colorado River ( es, Río Colorado) is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and northern Mexico. The river drains an expansive, arid watershed that encompasses parts of seven U.S. s ...
which flows westward through the southern part, and the Green River which 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.


Mexican portion

The Mexican Plateau is one of six distinct physiographic sections of the
Basin and Range Province The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating ...
, which in turn is part of the Intermontane Plateaus physiographic division. It is a large arid-to-semiarid
plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ...
that occupies much of northern and central
Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the southern portion of North America. It is borders of Mexico, bordered to the north by the United States; to the so ...
. Averaging above sea level, it extends from the United States border in the north to the Trans-Mexican Volcanic Belt in the south, and is bounded by the
Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...
and Sierra Madre Oriental to the west and east, respectively. A low east–west mountain range in the state of Zacatecas divides 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

* List of ecoregions in North America (CEC): Western Cordillera


References


External links

* {{Authority control Mountain ranges of North America Geologic provinces of Canada Geologic provinces of the United States Geology of Mexico Lists of mountain ranges Mountain ranges of Canada Mountain ranges of the United States Mountain ranges of Mexico