The Intermountain West, or Intermountain Region, is a

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, and ...

and geological region of the

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 Wes ...

. It is located between the front ranges of the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...

on the east and the Cascade Range 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 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 ...

topography. Some of the region's

river A river is a natural flowing watercourse, usually freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the ...

s reach 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 contine ...

, such as the Columbia River and

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 ...

. 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 streams ...

are in

endorheic basin An endorheic basin (; also spelled endoreic basin or endorreic basin) is a drainage basin that normally retains water and allows no outflow to other external bodies of water, such as rivers or oceans, but drainage converges instead into la ...

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 exceeds recharge. If the floor of a dry lake is covered by deposits of alkaline c ...

s or desert

sinks A sink is a bowl-shaped plumbing fixture for washing hands, dishwashing, and other purposes. Sinks have a tap (faucet) that supply hot and cold water and may include a spray feature to be used for faster rinsing. They also include a drain to ...

.
Portions of this region include: *

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, alternatin ...

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 ...

* Great Basin * Intermontane Plateaus

Climate

The

climate Climate is the long-term weather pattern in an area, 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 meteorologica ...

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 water bodies (such as oceans and large lakes) is carri ...

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 under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hai ...

from Pacific storms. The

winter Winter is the coldest season of the year in Polar regions of Earth, polar and temperate climates. It occurs after autumn and before spring (season), spring. The tilt of Axial tilt#Earth, Earth's axis causes seasons; winter occurs when a Hemi ...

weather depends on

latitude In geography, latitude is a 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 the south pole to 90° at the north po ...

. 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 The North American monsoon, variously known as the Southwest monsoon, the Mexican monsoon, the New Mexican monsoon, or the Arizona monsoon is a pattern of pronounced increase in thunderstorms and rainfall over large areas of the southwestern Uni ...

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 ( 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 ...

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 xērós, “dry") shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in thi ...

and temperate grasslands and shrublands

biome A biome () is a biogeographical unit consisting of a biological community that has formed in response to the physical environment in which they are found and a shared regional climate. Biomes may span more than one continent. Biome is a broader ...

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 fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial ...

habitat In ecology, the term habitat summarises the array of resources, physical and 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 ...

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, needlel ...

s biome vegetation, including groves and

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s of various species of

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family (biology), family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanic ...

, cedar,

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, from the Arcti ...

aspen Aspen is a common name for certain tree species; some, but not all, are classified by botanists in the section ''Populus'', of the ''Populus'' genus. Species These species are called aspens: *'' Populus adenopoda'' – Chinese aspen (Chin ...

, and other trees, and understory shrubs, and

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wide ...

s.
Intermountain West

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas o ...

s include: * Central Basin and Range ecoregion – ''North American Deserts; Level III ecoregion (EPA)'' * Columbia Plateau (ecoregion) – ''Temperate grasslands, savannas, and shrublands biome (WWF)'' * Eastern Cascades Slopes and Foothills (ecoregion) – ''Northwestern Forested Mountains; Level III ecoregion (EPA)'' * Great Basin shrub steppe – ''Deserts and xeric shrublands biome (WWF)'' * Great Basin montane forests – ''Temperate coniferous forest biome (WWF)'' * Northern Basin and Range ecoregion – ''North American Deserts; Level III ecoregion (EPA)'' * Palouse grasslands ecoregion – ''Temperate grasslands, savannas, and shrublands biome (WWF)'' * Snake River Plain (ecoregion) – ''North American Deserts; Level III ecoregion (EPA)'' * Wasatch and Uinta montane forests ecoregion – ''Temperate coniferous forest biome (WWF)'' Some sections are agriculturally cultivated with water diversions for irrigation systems. Cattle ranching 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. When the plants of the same kind are cultivated at one place on a large scale, it is called a crop. Most crops are cultivated in agriculture or hydroponi ...

include

corn Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn ( North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. ...

potatoes The potato is a starchy food, a tuber of the plant ''Solanum tuberosum'' and is a root vegetable native to the Americas. The plant is a perennial in the nightshade family Solanaceae. Wild potato species can be found from the southern United ...

sugar beets Sugar is the generic name for sweet-tasting, soluble carbohydrates, many of which are used in food. Simple sugars, also called monosaccharides, include glucose, fructose, and galactose. Compound sugars, also called disaccharides or double s ...

grass hay Hay is Graminoid, grass, legumes, or other herbaceous plants that have been cut and dried to be stored for use as animal fodder, either for large grazing animals raised as livestock, such as cattle, horses, domestic goat, goats, and sheep, or ...

, and alfalfa, 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 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, polar and cold temperate mammalian animals have been the mo ...

(northern areas), and 19th-century

westward expansion of the United States The United States of America was created on July 4, 1776, with the U.S. Declaration of Independence of thirteen British colonies in North America. In the Lee Resolution two days prior, the colonies resolved that they were free and independent ...

brought irreversible cultural changes. The completion of the

First transcontinental railroad North America's first transcontinental railroad (known originally as the "Pacific Railroad" and later as the " Overland Route") was a continuous railroad line constructed between 1863 and 1869 that connected the existing eastern U.S. rail netwo ...

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

Latter-day Saint Mormons are a religious and cultural group related to Mormonism, the principal branch of the Latter Day Saint movement started by Joseph Smith in upstate New York during the 1820s. After Smith's death in 1844, the movement split into sever ...

(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. Because of its low

population density Population density (in agriculture: Stock (disambiguation), standing stock or plant density) is a measurement of population per unit land area. It is mostly applied to humans, but sometimes to other living organisms too. It is a key geographical ...

and diverse economy, the survivalist writers

James Wesley Rawles James Wesley, Rawles (born 1960) is an American author, former United States Army, U.S. Army Intelligence officer, and retreat (survivalism), survival retreat consultant. Rawles describes himself as a Christian libertarianism, Constitutionalist ...

and Joel SkousenAbout Joel Skousen
both recommend the region as a preferred locale for "strategic relocation" and for building

survival retreat In the survivalist subculture or movement, a retreat is a place of refuge. Sometimes their retreats are called a bug-out location (BOL), a bunker, or a bolt hole. Survivalist retreats are intended to be self-sufficient and easily defended. Gen ...

s, thus referring to it as the American Redoubt.

Intermountain states

The intermountain states are generally considered to be

Nevada Nevada ( ; ) is a state in the 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. Nevada is the 7th-most extensive, ...

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 ...

Idaho Idaho ( ) is a 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 Montana and W ...

, the western third of

Montana Montana () is a U.S. state, state in the Mountain states, Mountain West List of regions of the United States#Census Bureau-designated regions and divisions, division of the Western United States. It is bordered by Idaho to the west, North ...

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a U.S. state, state in the Southwestern United States. It is the list of U.S. states and territories by area, 6th largest and the list of U.S. states and territories by population, 14 ...

north of the

Mogollon Rim The Mogollon Rim ( or or ) is a topographical and geological feature cutting across the northern half of the U.S. state of Arizona. It extends approximately , starting in northern Yavapai County and running eastward, ending near the borde ...

Colorado Colorado (, other variants) is a state in the Mountain states, 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 wes ...

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 encountere ...

westward,

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 ...

from the central mountain chain westward, and Far West Texas from the

Pecos River The Pecos River ( es, Río Pecos) 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 ...

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.

References