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 h ...

, 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 Pacific coast may be used to reference any coastline that borders the Pacific Ocean. Geography Americas Countries on the western side of the Americas have a Pacific coast as their western or southwestern border, except for Panama, where the Pac ...

) 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 ...

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 Western may refer to: Places *Western, Nebraska, a village in the US *Western, New York, a town in the US *Western Creek, Tasmania, a locality in Australia *Western Junction, Tasmania, a locality in Australia *Western world, countries that id ...

/ 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 In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...

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

, 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 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 the ...

in the west, the Nevadan belt in the middle (including the

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primar ...

), 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 Orogeny is a mountain building process. An orogeny is an event that takes place at a convergent plate margin when plate motion compresses the margin. An ''orogenic belt'' or ''orogen'' develops as the compressed plate crumples and is uplifted t ...

(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 A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of up to thousands of years ...

(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

, 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 Southeast Alaska, colloquially referred to as the Alaska(n) Panhandle, is the southeastern portion of the U.S. state of Alaska, bordered to the east and north by the northern half of the Canadian province of British Columbia (and a small part ...

, 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 Coast Mountains (french: La chaîne Côtière) are a major mountain range in the Pacific Coast Ranges of western North America, extending from southwestern Yukon through the Alaska Panhandle and virtually all of the Coast of British Columbi ...

, 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 The Canadian Rockies (french: Rocheuses canadiennes) or Canadian Rocky Mountains, comprising both the Alberta Rockies and the British Columbian Rockies, is the Canadian segment of the North American Rocky Mountains. It is the easternmost part ...

. 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 The Colorado Plateau, also known as the Colorado Plateau Province, is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. This province covers an area o ...

, 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 The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

– 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 The Sierra Madre Oriental () is a mountain range in northeastern Mexico. The Sierra Madre Oriental is part of the American Cordillera, a chain of mountain ranges (cordillera) that consists of an almost continuous sequence of mountain ranges that f ...

further east, surround the

Mexican Plateau The Central Mexican Plateau, also known as the Mexican Altiplano ( es, Altiplanicie Mexicana), is a large arid-to-semiarid plateau that occupies much of northern and central Mexico. Averaging above sea level, it extends from the United States b ...

.
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 The Sierra Madre del Sur is a mountain range in southern Mexico, extending from southern Michoacán east through Guerrero, to the Isthmus of Tehuantepec in eastern Oaxaca. Geography The Sierra Madre del Sur joins with the Eje Volcánico Tran ...

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 In physical geography, a fjord or fiord () is a long, narrow inlet with steep sides or cliffs, created by a glacier. Fjords exist on the coasts of Alaska, Antarctica, British Columbia, Chile, Denmark, Germany, Greenland, the Faroe Islands, Icela ...

, 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 The Santa Monica Mountains is a coastal mountain range in Southern California, next to the Pacific Ocean. It is part of the Transverse Ranges. Because of its proximity to densely populated regions, it is one of the most visited natural areas in ...

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 The Wrangell Mountains are a high mountain range of eastern Alaska in the United States. Much of the range is included in Wrangell-Saint Elias National Park and Preserve. The Wrangell Mountains are almost entirely volcanic in origin, and they i ...

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 The Kenai Mountains ( Dena'ina: ''Yaghanen Dghili'') are a mountain range in the U.S. state of Alaska. They extend 192 km (120 mi) northeast from the southern end of the Kenai Peninsula to the Chugach Mountains, and have an average ele ...

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 The Talkeetna Mountains (''Dghelaay tahwt’aene'' in Ahtna) () are a mountain range in Alaska. The Matanuska and Susitna River valleys, with towns such as Trapper Creek, Talkeetna, Wasilla, Palmer, Sutton, and Chickaloon, roughly bound the Ta ...

Western System of Canada

Snow covered mountains in Mount Robson (Unsplash)

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

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

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 The Fraser Canyon is a major landform of the Fraser River where it descends rapidly through narrow rock gorges in the Coast Mountains en route from the Interior Plateau of British Columbia to the Fraser Valley. Colloquially, the term "Fraser ...

northwestward, separating the

Interior Plateau The Interior Plateau comprises a large region of the Interior of British Columbia, and lies between the Cariboo and Monashee Mountains on the east, and the Hazelton Mountains, Coast Mountains and Cascade Range on the west.''Landforms of British C ...

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 The coastline of Norway is formed along the Skagerrak, North Sea, Norwegian Sea, and Barents Sea. This considers only the mainland coastline and excludes Svalbard. A straight line along Norway's sea borders (the coastal perimeter) is long. Alon ...

, 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 The Nass River is a river in northern British Columbia, Canada. It flows from the Coast Mountains southwest to Nass Bay, a sidewater of Portland Inlet, which connects to the North Pacific Ocean via the Dixon Entrance. Nass Bay joins Portland In ...

and the

Boundary Ranges The Boundary Ranges, also known in the singular and as the Alaska Boundary Range, are the largest and most northerly subrange of the Coast Mountains. They begin at the Nass River, near the southern end of the Alaska Panhandle in the Canadian pr ...

from there to their terminus in the

Territory at Champagne Pass and Chilkat Pass northwest of Haines, Alaska. The

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 Highland The Tagish Highland is an upland area on the inland side of the northernmost Boundary Ranges of the Coast Mountains, spanning far northwestern British Columbia from Atlin Lake to the area of the pass at Champagne, Yukon between the Alsek and Yuko ...

s and also the

Skeena Mountains The Skeena Mountains, also known as the Skeenas, are a subrange of the Interior Mountains of northern British Columbia, Canada, essentially flanking the upper basin of the Skeena River. They lie just inland from the southern end of the Boundary ...

, 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

. 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

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 The Insular Mountains are a range of mountains in the Pacific Coast Ranges on the Coast of British Columbia, Canada, comprising the Vancouver Island Ranges and Queen Charlotte Mountains. The Insular Mountains are rugged, particularly on Vancou ...

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 Haida Gwaii (; hai, X̱aaydag̱a Gwaay.yaay / , literally "Islands of the Haida people") is an archipelago located between off the northern Pacific coast of Canada. The islands are separated from the mainland to the east by the shallow Heca ...

in the north on the

British Columbia Coast , settlement_type = Region of British Columbia , image_skyline = , nickname = "The Coast" , subdivision_type = Country , subdivision_name = Canada , subdivision_type1 = Province , subdivision_name1 = British ...

. It contains two main mountain ranges, the

Vancouver Island Ranges The Vancouver Island Ranges, formerly called the Vancouver Island Mountains, are a series of mountain ranges extending along the length of Vancouver Island which has an area of . The Vancouver Island Ranges comprise the central and largest part ...

on Vancouver Island and the

Queen Charlotte Mountains The Queen Charlotte Mountains are a mountain range comprising all mountains and small mountain ranges of Haida Gwaii, British Columbia, Canada. It is the northernmost subrange of the Insular Mountains. They are subdivided into the Queen Charlotte ...

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

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

, 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 Olympic National Park is a United States national park located in the State of Washington, on the Olympic Peninsula. The park has four regions: the Pacific coastline, alpine areas, the west-side temperate rainforest, and the forests of the drier ...

. The

Oregon Coast Range The Oregon Coast Range, often called simply the Coast Range and sometimes the Pacific Coast Range, is a mountain range, in the Pacific Coast Ranges physiographic region, in the U.S. state of Oregon along the Pacific Ocean. This north-south ru ...

is the part of the Coast Range system that is denoted as between the mouth of the

Columbia River The Columbia River ( Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia ...

and the

Middle Fork Coquille River The Middle Fork Coquille River is a tributary, about long, of the South Fork Coquille River in the U.S. state of Oregon. It begins near Camas Mountain in Douglas County in the Southern Oregon Coast Range. It flows generally south, bypassing th ...

. 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

mountains in southwestern Mexico form a southern extension of the

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 The Hazelton Mountains are a grouping of mountain ranges on the inland lee of the Kitimat Ranges of the Coast Mountains in northwestern British Columbia, Canada, spanning the area of Hazelton south to the Nechako Reservoir. Defined by the Britis ...

Cassiar Mountains , photo = Cassiar Highway.jpg , photo_size = 280px , photo_caption = Cassiar Mountains along Stewart-Cassiar Highway near Good Hope Lake , country = Canada , subdivision1_type = Provinces , subdivision1 ...

, Omineca Mountains, and

South BC-NW USA-relief ColumbiaMtns wHighlands wcabinetsalish

The

are a designation in British Columbia for a group of four ranges lying between the

Rocky Mountain Trench The Rocky Mountain Trench, also known as the Valley of a Thousand Peaks or simply the Trench, is a large valley on the western side of the northern part of North America's Rocky Mountains. The Trench is both visually and cartographically a ...

(to the east) and the

(to the west). These ranges are the

Cariboo Mountains The Cariboo Mountains are the northernmost subrange of the Columbia Mountains, which run down into the Spokane area of the United States and include the Selkirks, Monashees and Purcells. The Cariboo Mountains are entirely within the province of ...

, which are the northernmost and sometimes considered to be part of the Interior Plateau, the

Selkirk Mountains The Selkirk Mountains are a mountain range spanning the northern portion of the Idaho Panhandle, eastern Washington, and southeastern British Columbia which are part of a larger grouping of mountains, the Columbia Mountains. They begin at Mica ...

, 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 River The Okanogan River (known as the Okanagan River in Canada) is a tributary of the Columbia River, approximately 115 mi (185 km) long, in southern British Columbia and north central Washington. It drains a scenic plateau region called th ...

s. 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

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 The Cabinet Mountains are part of the Rocky Mountains, located in northwest Montana and the Idaho panhandle, in the United States. The mountains cover an area of 2,134 square miles (5,527 km2). The Cabinet Mountains lie south of the Purcell M ...

south of the

Kootenai River The Kootenay or Kootenai river is a major river in the Northwest Plateau, in southeastern British Columbia, Canada, and northern Montana and Idaho in the United States. It is one of the uppermost major tributaries of the Columbia River, the l ...

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 Fraser may refer to: Places Antarctica * Fraser Point, South Orkney Islands Australia * Fraser, Australian Capital Territory, a suburb in the Canberra district of Belconnen * Division of Fraser (Australian Capital Territory), a former federal e ...

and

Thompson River The Thompson River is the largest tributary of the Fraser River, flowing through the south-central portion of British Columbia, Canada. The Thompson River has two main branches, the South Thompson River and the North Thompson River. The ri ...

s. 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

. 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

(called the

Cascade Mountains The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, a ...

in Canada) extends from

northern California Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...

in the United States to

, 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 Mount Rainier (), indigenously known as Tahoma, Tacoma, Tacobet, or təqʷubəʔ, is a large active stratovolcano in the Cascade Range of the Pacific Northwest, located in Mount Rainier National Park about south-southeast of Seattle. With a ...

(), a

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and peri ...

. 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 Glacier Peak or Dakobed (known in the Sauk-Suiattle dialect of the Lushootseed language as "Tda-ko-buh-ba" or "Takobia") is the most isolated of the five major stratovolcanoes (composite volcanoes) of the Cascade Volcanic Arc in the U.S state ...

, known as the

North Cascades The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in the U.S. and Canada as the Casca ...

, and its northern and eastern extremities verge on the

Thompson Plateau The Thompson Plateau forms the southern portion of the Interior Plateau of British Columbia, Canada, lying to the west of Okanagan Lake, south of the Thompson River and east of (although never adjoining it) the Fraser River. At its most southern p ...

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 Lassen Peak ( ), commonly referred to as Mount Lassen, is a lava dome volcano and the southernmost active volcano in the Cascade Range of the Western United States. Located in the Shasta Cascade region of Northern California, it is part of the ...

, and are more severely alpine and steeply rugged, particularly the

Skagit Range The Skagit Range ( ) is a subrange of the Cascade Range in southwestern British Columbia, Canada and northwestern Washington, United States, which are known in Canada as the Canadian Cascades or, officially, the Cascade Mountains. The Skagit Rang ...

. 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

forms an inland mountain spine of northern California, extending from the terminus of the

south of

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 The Transverse Ranges are a group of mountain ranges of southern California, in the Pacific Coast Ranges physiographic region in North America. The Transverse Ranges begin at the southern end of the California Coast Ranges and lie within Santa ...

, 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 Mount Whitney ( Paiute: Tumanguya; ''Too-man-i-goo-yah'') is the highest mountain in the contiguous United States and the Sierra Nevada, with an elevation of . It is in East– Central California, on the boundary between California's Inyo and ...

(), the highest point in the

contiguous United States The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...

. 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 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 and thin ridges called

arête An arête ( ) is a narrow ridge of rock which separates two valleys. It is typically formed when two glaciers erode parallel U-shaped valleys. Arêtes can also form when two glacial cirques erode headwards towards one another, although frequ ...

Sierra Madre Occidental in Mexico

The

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 The Laramie Mountains are a range of moderately high peaks on the eastern edge of the Rocky Mountains in the U.S states of Wyoming and Colorado. The range is the northernmost extension of the line of the ranges along the eastern side of the R ...

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 Jacques La Ramée (June 8, 1784 – 1821) was a French-Canadian and Métis coureur des bois, frontiersman, trapper, fur trader, hunter, explorer, and mountain man who lived in what is now the U.S. state of Wyoming, having settled there in 18 ...

, 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

from near the northern opening of the Bering Strait to the northern

Territory. Major subranges include the

British Mountains The British Mountains are a mountain range in 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 ...

and

Richardson Mountains The Richardson Mountains are a mountain range located west of the mouth of the Mackenzie River in northern Yukon, Canada. They parallel the northernmost part of the boundary between Yukon and Northwest Territories. Although some sources conside ...

, towards their eastern end, and at their farthest west is the small subrange that

De Long Mountains The De Long Mountains are a mountain range in the North Slope Borough of the U.S. state of Alaska. The range is located at the west end of the Brooks Range and extends west from Uivaksak Creek and the head of the Kuna River Kuna may refer to: ...

. The Brooks Range forms the northern flank of the lower

Yukon River The Yukon River ( Gwich'in: ''Ųųg Han'' or ''Yuk Han'', Yup'ik: ''Kuigpak'', Inupiaq: ''Kuukpak'', Deg Xinag: ''Yeqin'', Hän: ''Tth'echù'' or ''Chuu k'onn'', Southern Tutchone: Chu Nìikwän, russian: Юкон, Yukon) is a major watercour ...

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 Beaufort Sea (; french: Mer de Beaufort, Iñupiaq: ''Taġiuq'') is a marginal sea of the Arctic Ocean, located north of the Northwest Territories, the Yukon, and Alaska, and west of Canada's Arctic islands. The sea is named after Sir ...

. 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

Rocky Mountain System in contiguous U.S.

In the

, the highest peak is

Mount Elbert Mount Elbert is the highest summit of the Rocky Mountains, the highest point in the U.S. state of Colorado, and the second-highest summit in the contiguous United States (after Mount Whitney). The ultra-prominent fourteener is the highest pea ...

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

to the west, and extend south to the

Rio Grande The Rio Grande ( and ), known in Mexico as the Río Bravo del Norte or simply the Río Bravo, is one of the principal rivers (along with the Colorado River) in the southwestern United States and in northern Mexico. The length of the Rio G ...

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 The Salish Mountains are located in the northwest corner of the U.S. State of 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 ...

of Idaho and Montana, whereas their counterparts north of the

, the

, are sometimes considered a separate system lying to the west of the huge

which runs the length of British Columbia.

Sierra Madre Oriental in Mexico

The

mountains in eastern Mexico are a southern extension of the

.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

is the northern continuation of the

, and covers much of inland

. The

and Monashee Mountains lie to the east, the

Canadian Cascades The North Cascades are a section of the Cascade Range of western North America. They span the border between the Canadian province of British Columbia and the U.S. state of Washington and are officially named in the U.S. and Canada as the Cascad ...

are to the southwest, and the

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

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

on the east and northeast. Also within the Interior plateau, the

forms the southern portion of the Interior Plateau. It is bordered on the south by the

and on the north by the

. The Okanagan Highland is the part of the Interior Plateau to the east of the Thompson Plateau, and is bounded by the

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

and northern

. The Interior Plateau also includes the

Quesnel Highland The Quesnel Highland is a geographic area in the Central Interior of the Canadian province of British Columbia. As defined by BC government geographer in ''Landforms of British Columbia'', an account and analysis of British Columbia geography tha ...

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

, stretching inland and parallel to the

coast. Its northern half is referred to as the

Sacramento Valley , photo =Sacramento Riverfront.jpg , photo_caption= Sacramento , map_image=Map california central valley.jpg , map_caption= The Central Valley of California , location = California, United States , coordinates = , boundaries = Sierra Nevada (ea ...

, 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

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 The Willamette Valley ( ) is a long valley in Oregon, in the Pacific Northwest region of the United States. The Willamette River flows the entire length of the valley and is surrounded by mountains on three sides: the Cascade Range to the eas ...

lies between the

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

from the

on the

Mexican Mexican may refer to: Mexico and its culture *Being related to, from, or connected to the country of Mexico, in North America ** People *** Mexicans, inhabitants of the country Mexico and their descendants *** Mexica, ancient indigenous people ...

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

is a large valley that extends approximately from

Flathead Lake Flathead Lake ( fla, člq̓etkʷ, label= Salish, kut, yawuʔnik̓ ʔa·kuq̓nuk) is a large natural lake in northwest Montana. The lake is a remnant of the ancient, massive glacial dammed lake, Lake Missoula of the era of the last interglacia ...

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 The Liard River of the North American boreal forest flows through Yukon, British Columbia and the Northwest Territories, Canada. Rising in the Saint Cyr Range of the Pelly Mountains in southeastern Yukon, it flows southeast through British Co ...

, just south of the

–

border near

Watson Lake, Yukon Watson Lake is a town in Yukon, Canada, located at mile 635 on the Alaska Highway close to the British Columbia border. It has a population of 790 in 2016. The town is named for Frank Watson, an American-born trapper and prospector, who settled in ...

. 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

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 In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

. The Trench separates the

on its east from the

and the

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,

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

is a

geologic Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other E ...

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

s of

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 A flood basalt (or plateau basalt) is the result of a giant volcanic eruption or series of eruptions that covers large stretches of land or the ocean floor with basalt lava. Many flood basalts have been attributed to the onset of a hotspot reac ...

plateau between the

and the

, cut through by the

. 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 ...

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 ...

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

, as well as much of northern

. It is an extremely arid region characterized by basin and range topography. The

is an area of high desert located in

, and

, 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

is one of six distinct physiographic sections of the

, which in turn is part of the

Intermontane Plateaus In the context of physical geography, the Intermontane Plateaus is one of eight physiographic regions of the contiguous United States. The region consists mostly of plateaus and mountain ranges lying between the Rocky Mountains on the east and t ...

physiographic division. It is a large arid-to-semiarid

that occupies much of northern and central

. Averaging above sea level, it extends from the United States border in the north to the

Trans-Mexican Volcanic Belt The Trans-Mexican Volcanic Belt ( es, Eje Volcánico Transversal), also known as the Transvolcanic Belt and locally as the (''Snowy Mountain Range''), is an active volcanic belt that covers central-southern Mexico. Several of its highest peaks h ...

in the south, and is bounded by the

and

to the west and east, respectively. A low east–west mountain range in the state of

Zacatecas , image_map = Zacatecas in Mexico (location map scheme).svg , map_caption = State of Zacatecas within Mexico , coordinates = , coor_pinpoint = , coordinates_footnotes = , subdivision_type ...

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.

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

Major features

Pacific Coast Belt

Southern Alaska ranges

Western System of Canada

Pacific Border Province in contiguous U.S.

Western mountain ranges of Mexico

Nevadan belt

Interior System of Canada

Cascade–Sierra Mountains in contiguous U.S.

Sierra Madre Occidental in Mexico

Laramide Belt

Alaska and Eastern System of Canada

Rocky Mountain System in contiguous U.S.

Sierra Madre Oriental in Mexico

Intermontane areas seaward from the Nevadan belt

Canadian portion

Portion in contiguous U.S.

Mexican portion

Intermontane areas inland from the Nevadan belt

Canadian portion

Portion in contiguous U.S.

Mexican portion

See also

References

External links