The Intermountain West, or Intermountain Region, is a

geographic Geography (from Ancient Greek ; combining 'Earth' and 'write', literally 'Earth writing') is the study of the lands, features, inhabitants, and phenomena of Earth. Geography is an all-encompassing discipline that seeks an understanding o ...

and geological region of the

Western United States The Western United States (also called the American West, the Western States, the Far West, the Western territories, and the West) is List of regions of the United States, census regions United States Census Bureau. As American settlement i ...

. It is located between the

Rocky Mountain Front The Rocky Mountain Front is a somewhat unified geologic and ecosystem area in North America where the eastern slopes of the Rocky Mountains meet the plains. In 1983, the Bureau of Land Management called the Rocky Mountain Front "a nationally signi ...

on the east and the

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

and

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 primari ...

on the west.

Topography

The Intermountain West has a

basin and range Basin and range topography is characterized by alternating parallel mountain ranges and valleys. It is a result of crustal extension due to mantle upwelling, gravitational collapse, crustal thickening, or relaxation of confining stresses. The e ...

and

plateau In geology and physical geography, a plateau (; ; : plateaus or plateaux), 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. ...

topography. Some of the region's

river A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of ...

s reach the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

, such as the

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

and

Colorado River The Colorado River () is one of the principal rivers (along with the Rio Grande) in the Southwestern United States and in northern Mexico. The river, the List of longest rivers of the United States (by main stem), 5th longest in the United St ...

. Other regional rivers and

streams A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long, large stream ...

are in

endorheic basin An endorheic basin ( ; also endoreic basin and endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water (e.g. rivers and oceans); instead, the water drainage flows into permanent ...

s and cannot reach the sea, such as the

Walker River The Walker River is a river in west-central Nevada in the United States, approximately long. Fed principally by snowmelt from the Sierra Nevada of California, it drains an arid portion of the Great Basin southeast of Reno and flows into the endo ...

and

Owens River The Owens River is a river in eastern California in the United States, approximately long.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map accessed March 17, 2011, It drains into and through the ...

. These flow into

brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...

or seasonally

dry lake A dry lake bed, also known as a playa (), is a basin or depression that formerly contained a standing surface water body, which disappears when evaporation processes exceed recharge. If the floor of a dry lake is covered by deposits of alkalin ...

s or desert

sinks A sink (also known as ''basin'' in the UK) is a bowl-shaped plumbing fixture for washing hands, dishwashing, and other purposes. Sinks have a tap (faucet) that supplies hot and cold water and may include a spray feature to be used for faste ...

.
Portions of this region include: *

Basin and Range Province The Basin and Range Province is a vast United States physiographic region, physiographic region covering much of the inland Western United States and Northern Mexico, northwestern Mexico. It is defined by unique basin and range topography, charac ...

Colorado Plateau The Colorado Plateau is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the Southwestern United States. This plateau covers an area of 336,700 km2 (130,000 mi2) within w ...

Great Basin The Great Basin () is the largest area of contiguous endorheic watersheds, those with no outlets to the ocean, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja Californi ...

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 ...

Climate

The

climate Climate is the long-term weather pattern in a region, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteoro ...

of the Intermountain Region is affected by location and elevation. The sub-regions are in

rain shadow A rain shadow is an area of significantly reduced rainfall behind a mountainous region, on the side facing away from prevailing winds, known as its leeward side. Evaporated moisture from body of water, bodies of water (such as oceans and larg ...

s from the Cascade or Sierra Nevada ranges that block

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls from clouds due to gravitational pull. The main forms of precipitation include drizzle, rain, rain and snow mixed ("sleet" in Commonwe ...

from Pacific storms. The

winter Winter is the coldest and darkest season of the year in temperate and polar climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Dif ...

weather depends on

latitude In geography, latitude is a geographic coordinate system, geographic coordinate that specifies the north-south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from −90° at t ...

. In the southern portion, winters are shorter, warmer and have less winter precipitation and snow. In the northern portion, winters are cold and moist. All areas have hot summers. North American Monsoon storms can occur in the region during the mid-summer, coming northeast from the

and

Mexican Plateau The Central Mexican Plateau, also known as the Mexican Altiplano (), 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 border in the north to the T ...

Natural history

The

flora Flora (: floras or florae) is all the plant life present in a particular region or time, generally the naturally occurring (indigenous (ecology), indigenous) native plant, native plants. The corresponding term for animals is ''fauna'', and for f ...

at lower elevations includes

deserts and xeric shrublands Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (Ancient Greek 'dry') shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this habitat ...

and temperate grasslands and shrublands

biome A biome () is a distinct geographical region with specific climate, vegetation, and animal life. It consists of a biological community that has formed in response to its physical environment and regional climate. In 1935, Tansley added the ...

vegetation. Higher elevation

montane Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures lapse rate, fall as elevation increases, causing the ecosystem to stratify. This stratification is ...

habitat In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ...

s include

temperate coniferous forest Temperate coniferous forest is a terrestrial biome defined by the World Wide Fund for Nature. Temperate coniferous forests are found predominantly in areas with warm summers and cool winters, and vary in their kinds of plant life. In some, needle ...

s biome vegetation, including groves and

forest A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...

s of various species of

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. ''World Flora Online'' accepts 134 species-rank taxa (119 species and 15 nothospecies) of pines as cu ...

cedar Cedar may refer to: Trees and plants *''Cedrus'', common English name cedar, an Old-World genus of coniferous trees in the plant family Pinaceae * Cedar (plant), a list of trees and plants known as cedar Places United States * Cedar, Arizona ...

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' ( ) of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere as far south ...

aspen Aspen is a common name for certain tree species in the Populus sect. Populus, of the ''Populus'' (poplar) genus. Species These species are called aspens: * ''Populus adenopoda'' – Chinese aspen (China, south of ''P. tremula'') * ''Populus da ...

, and other trees, and understory

shrub A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...

s, and

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

s.
Intermountain West

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

s include: *

Cascade Mountains leeward forests The Cascade Mountains leeward forests are a temperate coniferous forest ecoregion of North America, as defined by the World Wildlife Fund (WWF) categorization system. Setting This is a band of mountain habitat running north–south along the lee ...

- ''Temperate coniferous forest biome (WWF)'' * Eastern Cascades Slopes and Foothills (ecoregion) – ''Northwestern Forested Mountains; Level III ecoregion (EPA)'' *

Columbia Plateau (ecoregion) The Columbia Plateau ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) encompassing approximately of land within the U.S. states of Washington, Oregon, and Idaho. The ecoregion extends ac ...

– ''Temperate grasslands, savannas, and shrublands biome (WWF)'' * Palouse grasslands ecoregion – ''Temperate grasslands, savannas, and shrublands biome (WWF)'' *

North Central Rockies forests The North Central Rockies forests is a temperate coniferous forest ecoregion of Canada and the United States. This region overlaps in large part with the North American inland temperate rainforest and gets more rain on average than the South Ce ...

- ''Temperate coniferous forest biome (WWF)'' *

South Central Rockies forests The South Central Rockies forests is a temperate coniferous forest ecoregion of the United States located mainly in Wyoming, Idaho, and Montana. It has a considerably drier climate than the North Central Rockies forest. Setting This ecoregion ...

- ''Temperate coniferous forest biome (WWF)'' *

Snake River Plain (ecoregion) The Snake River Plain ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Idaho and Oregon. It follows the Snake River across Idaho, stretching roughly from the Wyoming ...

– ''North American Deserts; Level III ecoregion (EPA)'' * Montana Valley and Foothill grasslands - ''Temperate grasslands, savannas, and shrublands biome (WWF)'' * Wyoming Basin shrub steppe - ''Deserts and xeric shrublands biome (WWF)'' *

Central Basin and Range ecoregion The Great Basin Desert is part of the Great Basin between the Sierra Nevada and the Wasatch Range in the western United States. The desert is a geographical region that largely overlaps the Great Basin shrub steppe defined by the World Wildlife ...

– ''North American Deserts; Level III ecoregion (EPA)'' * Great Basin shrub steppe – ''Deserts and xeric shrublands biome (WWF)'' *

Great Basin montane forests The Great Basin montane forests is an ecoregion of the Temperate coniferous forests biome, as designated by the World Wildlife Fund (WWF). Geography The Great Basin montane forests ecoregion is located in the Great Basin region of Nevada, easte ...

– ''Temperate coniferous forest biome (WWF)'' *

Northern Basin and Range ecoregion The Northern Basin and Range ecoregion is a List of ecoregions in the United States (EPA), Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Oregon, Idaho, Nevada, Utah, and California ...

– ''North American Deserts; Level III ecoregion (EPA)'' * Wasatch and Uinta montane forests ecoregion – ''Temperate coniferous forest biome (WWF)'' * Colorado Rockies forests - ''Temperate coniferous forest biome (WWF)'' * Colorado Plateau Shrublands - ''Deserts and xeric shrublands biome (WWF)'' *

Arizona Mountains forests The Arizona Mountains forests are a temperate coniferous forests ecoregion of the southwest United States with a rich variety of woodland habitats and wildlife. Setting This is a landscape of steep mountains and high stony plateaus with rocky ou ...

- ''Temperate coniferous forest biome (WWF)'' Some sections are agriculturally cultivated with water diversions for

irrigation systems Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has be ...

Cattle ranching A ranch (from /Mexican Spanish) is an area of land, including various structures, given primarily to ranching, the practice of raising grazing livestock such as cattle and sheep. It is a subtype of farm. These terms are most often applied to li ...

is practiced in the region as well. Cultivated

crops A crop is a plant that can be grown and harvested extensively for profit or subsistence. In other words, a crop is a plant or plant product that is grown for a specific purpose such as food, fibre, or fuel. When plants of the same species a ...

include

corn Maize (; ''Zea mays''), also known as corn in North American English, is a tall stout Poaceae, grass that produces cereal grain. It was domesticated by indigenous peoples of Mexico, indigenous peoples in southern Mexico about 9,000 years ago ...

potatoes The potato () is a starchy tuberous vegetable native to the Americas that is consumed as a staple food in many parts of the world. Potatoes are underground stem tubers of the plant ''Solanum tuberosum'', a perennial in the nightshade famil ...

sugar beets A sugar beet is a plant whose root contains a high concentration of sucrose and that is grown commercially for sugar production. In plant breeding, it is known as the Altissima cultivar group of the common beet (''Beta vulgaris''). Together with ...

, grass hay, and

alfalfa Alfalfa () (''Medicago sativa''), also called lucerne, is a perennial plant, perennial flowering plant in the legume family Fabaceae. It is cultivated as an important forage crop in many countries around the world. It is used for grazing, hay, ...

, the latter two crops are used for livestock feed.

Demographics and sociology

For thousands of years the Intermountain West has been the homeland for many

Native American Native Americans or Native American usually refers to Native Americans in the United States. Related terms and peoples include: Ethnic groups * Indigenous peoples of the Americas, the pre-Columbian peoples of North, South, and Central America ...

cultures, tribes, and bands. The 18th-century

fur trade The fur trade is a worldwide industry dealing in the acquisition and sale of animal fur. Since the establishment of a world fur market in the early modern period, furs of boreal ecosystem, boreal, polar and cold temperate mammalian animals h ...

(northern areas), and 19th-century

westward expansion of the United States The United States of America was formed after thirteen British colonies in North America United States Declaration of Independence, declared independence from the British Empire on July 4, 1776. In the Lee Resolution, passed by the Second Conti ...

brought irreversible cultural changes. The completion of the

First transcontinental railroad America's first transcontinental railroad (known originally as the "Pacific Railroad" and later as the "Overland Route (Union Pacific Railroad), Overland Route") was a continuous railroad line built between 1863 and 1869 that connected the exis ...

through the region accelerated non-native settlements and development. Historically, the Intermountain West area centered in Utah is associated with

Latter-day Saint The Latter Day Saint movement (also called the LDS movement, LDS restorationist movement, or Smith–Rigdon movement) is the collection of independent church groups that trace their origins to a Christian Restorationist movement founded b ...

(Mormon) settlements, and the region has the highest percentage of LDS members in the United States currently. That region is also known as the

Mormon Corridor The Mormon corridor are the areas of western North America that were settled between 1850 and approximately 1890 by members of the Church of Jesus Christ of Latter-day Saints (LDS Church), who are commonly called "Mormons". In academic literatu ...

Intermountain states

The intermountain states are generally considered to be

Nevada Nevada ( ; ) is a landlocked state in the Western United States. It borders Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the seventh-most extensive, th ...

Utah Utah is a landlocked state in the Mountain states, Mountain West subregion of the Western United States. It is one of the Four Corners states, sharing a border with Arizona, Colorado, and New Mexico. It also borders Wyoming to the northea ...

Idaho Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...

, the western third of

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

north of the

Mogollon Rim The Mogollon Rim ( or or ) is a topography, topographical and geological feature cutting across Northern Arizona, the northern half of the U.S. state of Arizona. It extends approximately , starting in northern Yavapai County, Arizona, Yavapa ...

Colorado Colorado is a U.S. state, state in the Western United States. It is one of the Mountain states, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas ...

from the

Front Range The Front Range is a mountain range of the Southern Rocky Mountains of North America located in the central portion of the U.S. State of Colorado, and southeastern portion of the U.S. State of Wyoming. It is the first mountain range encounter ...

westward,

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

from the central mountain chain westward,

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

east of the Sierra Nevada and Cascade ranges, and

Far West Texas The Trans-Pecos, as originally defined in 1887 by the Texas geologist Robert T. Hill, is the distinct portion of Texas that lies west of the Pecos River. The term is considered synonymous with Far West Texas, a subdivision of West Texas. The Tra ...

from the

Pecos River The Pecos River ( ; ) originates in north-central New Mexico and flows into Texas, emptying into the Rio Grande. Its headwaters are on the eastern slope of the Sangre de Cristo mountain range in Mora County north of Pecos, New Mexico, at an elev ...

westward. The intermountain states are so named from having all or portions between the Rockies, Sierras, and Cascades. The intermountain states are included among states classified as the

Mountain States The Mountain states (also known as the Mountain West or the Interior West) form one of the nine geographic divisions of the United States that are officially recognized by the United States Census Bureau. It is a subregion of the Western Un ...

References