copyright Alan A. Lew, 2004, all rights reserved


Virtual Fieldtrip to the Southwest

Note: Links marked with an asterisk (*) are optional.








The Mountain West is the largest and most diverse region in the US. If the population densities of this region were greater, it would, in all likelihood, be divided into several different regions. However, the US Bureau of the Census, along with most geographers, treat this vast area from the Rockies to the Sierra Nevada and Cascade Ranges as a single entity. Increasingly, the southern portion of the Mountain West is being discussed separately as the American Southwest. This chapter discusses the Mountain West in general, along with the distinct characteristics of the Southwest.


The Mountain West is diverse. Its physiography varies from the highest peaks of the 48 contiguous states to flat deserts and the lowest point in North America. While rainfall in the Cascade Range reaches over 100 inches a year, it is less than 10 inches in the southwestern deserts. Major Native American and Hispanic culture groups are concentrated in the southern portion of the region, while the distinct Mormon religious culture predominates in the state of Utah. Some communities are dominated by irrigated agriculture, others by ranching, mining, or tourism.


The Mountain West has experienced the fastest growth rates of any region in the US. However, because it has the lowest population densities in the US, the total population increase is lower than in the Southeast or Pacific Coast regions. In fact, the low population density is the one homogeneous characteristic which unifies the Mountain West as a region. Another characteristic is income. The Mountain West has the lowest income levels in the US, although the southwestern portion is slightly higher than incomes in the southeastern US (based on 1988 figures).

Chapter Outline

The first part of this chapter discusses the physical geography of the entire Mountain West, from the Rocky Mountains to the Sierra Nevada and Cascade Ranges. This is followed by a discussion of human settlement geography in the region, with particular emphasis on the portion known as the Southwest (Arizona and New Mexico), and focusing on Native Americans, Hispanics, and US-Mexico relations. Mormon Utah is then discussed as a somewhat unique example of northern European settlement in the Mountain West.

Physical Geography of the Mountain West



There are three basic physiographic provinces in the Mountain West: (1) the Rocky Mountains, (2) the Intermountain Basin and Plateaus and (3) the West Coast Mountains System, including the Sierra Nevada, which will be covered in more detail in the Pacific Coast chapter (chapter 10).

North America Physiographic Regions Map

US Landforms Map


Subduction: How the West Was Formed

The entire area from the Rocky Mountains westward was formed by the rapid movement of the North American continent westward after it broke away from Europe and Africa about 200 million years ago. As the continent moved westward, it overrode the plate which then comprised the bottom of the Pacific Ocean. When an ocean floor plate is pushed under an advancing continental plate, the process is known as "subduction." As it is pushed downward into the earth, the subducting ocean plate is heated, and some of its more volatile rock material melts. This melted rock is known as magma.


Volcanic Mountain Chains

The magma finds its way up through cracks in the continental plate and may eventually erupt onto the surface of the continent in violent volcanic explosions. This is the process that forms the great volcanic mountain chain in the Andes of South America: the Pacific Ocean floor is melting underneath South America and pushing up the Andes volcanoes. This is the same process that forms the volcanic Cascade Range, which stretches from Mount Lassen in northern California to Mount Baker on the Canadian border.

Volcanoes in the West - National Atlas of the US



Batholith Mountains

Magma, however, does not always make it to the surface. Most of it cools and solidifies underneath the surface of the earth. These are known as "plutonic intrusions," the largest of which is called a batholith. Such intrusions may be unearthed millions of years later as the dirt and rock above them erodes away. Granite is the most common rock type which indicates an exposed batholith. Sedimentary rock, twisted and distorted by the intrusive magma, is also common in batholith mountain areas. The Rocky Mountains and the Sierra Nevada Mountains were primarily formed in this way. As with the Cascade Range, it was the melting of the oceanic plate deep underneath the North American plate that pushed up the material to form these mountain systems.

The Rocky Mountains

What is unique about the Rocky Mountain Range is that it is so far inland from the coast. In most areas where subduction mountain building occurs, it is very close to the coastal edge of the continent. It is speculated that the Rocky Mountains formed so far inland because of the speed at which North America overrode the Pacific Ocean plate. Because it was moving so rapidly, subduction of the ocean floor did not have time to occur right at the edge of the continent. Instead, it took place far inland, where the Rockies are today.

Idaho Physiography Map - The Northern Rocky Mountains


Colorado Physiography Map - The Front Range of the Rocky Mountains


Mountain Building Today

The subduction of the Pacific Ocean floor underneath the North American continent is generally no longer taking place today. Only in the Pacific Northwest is a small remnant plate (known by various names, including the Juan de Fuca Plate and the Gorda Plate) subducting under North America to form the Cascades. Instead, North America today is sliding sideways against the Pacific Ocean floor. Mountain building in the West, therefore, has slowed (along with volcanic eruptions and earthquakes), and erosion forces have become more predominant.

Alpine Glaciation

One of the major erosion forces that has shaped the western mountains is ice. Unlike the blanket continental glaciers that covered the Midwest, the ice ages brought Alpine Glaciers to the mountains of the West. Mountain glaciers existed as far south as New Mexico. As they slowly flowed down from mountain peaks, they carved steep and jagged ridgelines and deep U-shaped valleys. Yosemite Valley in California's Yosemite National Park* is an example of a U-shaped valley cut by a glacier.

Intermountain Basin and Plateau Region

Between the Rocky Mountains and the Sierra Nevada and Cascade Ranges lies the Intermountain Basin and Plateau Region. This broad, expansive region is actually older than the Rocky Mountains and Sierra Nevada Range. It was the West's first major mountain chain, 80 million years ago. As mountain-building activity moved eastward to build the Rockies 60 million years ago, the older system lost the magma underneath the earth's surface that supported its uplift. This resulted in a mix of higher-elevation plateaus and mountains and lower-lying basins (also with mountains). The two major plateaus are the Colorado Plateau and the Columbia Plateau. The major basin area is the Basin and Range geologic region or province, of which the Great Basin, Mojave (or Mohave) Desert, and Sonoran Desert are part.

US Geology Map - Colorado & Columbia Plateaus, and Basin & Range


The Colorado Plateau: Boundaries

The Colorado Plateau is centered on the Four Corners area, where the states of Colorado, New Mexico, Arizona, and Utah come together. Its boundaries are:


Before it became attached to the North American continent, the Colorado Plateau was a large area of island volcanoes. Today, the Colorado Plateau is a vast area of uplifted sedimentary rock, much of it formed when the land was under or just above sea level.


Geologically, most of the Colorado plateau is composed of uplifted and slightly tilted sedimentary rock. The Grand Canyon presents a good picture of the underlying rock structure of the region. At the very bottom of the Grand Canyon, the Colorado River (which drains the entire plateau) cuts through ancient metamorphic rock: the last remnant of a continent that existed long before North America. Above this are successive layers of
- mudstone (from when the Southwest formed the bed of a shallow sea),
- sandstone (from when the region was covered with sand dunes), and
- alluvium mixed with volcanic ash and petrified wood (from times when the area had many rivers, forests, and volcanic activity).

Almost all of the Colorado Plateau consists of these layers of uplifted sedimentary rock. Their exposure in the Grand Canyon, Zion Canyon, and Bryce Canyon make for some of the most spectacular scenery in the world. Surface volcanism is more common on the edges of the Colorado Plateau, such as at San Francisco Mountain in northern Arizona and the San Juan Range in Colorado and New Mexico.

The Columbia Plateau: Boundaries

The Columbia Plateau is a large area centered on the scablands of eastern Washington. The entire plateau is drained by the Columbia River. Its boundaries are less distinct than those of the Colorado Plateau but are approximately as follows:


Unlike the Colorado Plateau, the Columbia Plateau is comprised primarily of old volcanic lava flows. These lava flows originated from giant fissures in the surface of the earth and are over 2,000 feet thick in some areas. Like the Colorado Plateau, the rock structure is flat and horizontal. However, because the material is all lava, the gorges cut by the Columbia River and its major tributary, the Snake River, are not as colorful as the Colorado's Grand Canyon, though they are much deeper.

The Basin and Range Province: Location

The Basin and Range geologic province is located south of the Columbia Plateau and west and south of the Colorado Plateau. The region is the most arid in the US and includes all of Nevada, the Bonneville Salt Flats of Utah, the Death Valley and the Mojave Desert in California, and the Sonoran Desert of southern Arizona and into northern Mexico. Most of the Nevada portion of the Basin and Range region is also known as the Great Basin.


The Basin and Range region is named after the series of linear mountain ranges separated by broad, flat plains that characterize this part of the US. Most of these ranges are short, under 100 miles in length, and trend in a north-south direction (although the pattern in the south is mixed). These mountain systems are the jagged edges of giant blocks of the earth's crust that were uplifted by the same plate tectonic processes that built the mountains and plateaus of the rest of the Mountain West. However, there was insufficient material within the earth to support this uplift, so the blocks of earth caved in on each other. Erosion has worn away the taller mountains that once existed, filling in the valleys between them and resulting in the pattern exhibited today.

The Great Basin

The Great Basin, between the Sierra Nevada Range of California and the Wasatch Range of Utah, has an internal drainage system with no outlet to the oceans. During the last glacial period, there were large lakes scattered throughout Nevada and western Utah. Water flowed into the Great Basin, but high evaporation rates resulted in the gradual shrinking of these lakes. The lakes also became increasingly saltier because of the salt that is left behind when the water evaporated. The Great Salt Lake is all that remains of the once massive Lake Bonneville. The old shorelines of this lake can still be clearly seen on the hills above Salt Lake City. (Higher than average snowfalls on the Colorado Plateau have resulted in a rise in the level of the Great Salt Lake since the late 1970s, causing considerable damage and concern in northern Utah.)

Arid Climate

The Mountain West contains all of the major desert in the US. Lack of water is the principal reason for the low population density of the region, and has considerable influence in shaping settlement patterns. There are two reasons for the high aridity of the Mountain West: (1) its latitude and west coast location and (2) the rainshadow effect.

Vegetation Triangle Diagram

US Mean Annual Temperature 1998 Map - The Sun Belt


US Shrub Cover Map


Mountain West Climate

East Coast Global Climate Patterns

If one looks at the global pattern of climate, distinct differences appear between East and West coast locations of continents. East coast locations are all humid. The major differences are that locations closer to the equator are warm and humid, while those farther to the north are cold and humid.

West Coast Global Climate Patterns and Hadley Cells

West coast climates display a pattern of (1) high humidity at the equator, (2) dry just north and south of the equator, (3) wet again at higher latitudes, and (4) dry again toward the North and South Poles. All of the world's major desert areas are located on the west side of continents. The reason for this lies in "Hadley Cells." These are large air movements in which rising, wet air brings rain to the equator, dries out by the time it drops down over the deserts, brings more moisture into the air northward (around the rainy Pacific Northwest) and southward, then again dries out as it descends over the North and South Poles. The circle created by the air's rising, falling, then rising again is the Hadley "Cell." The Mountain West happens to be located at a latitude dominated by dry, falling air. This "high pressure" system weakens in the northernmost Mountain West, which can receive up to 40 inches of rain a year.

Hadley Cells Diagram


Rainshadow Effect

Most of the Pacific Coast of Oregon and Washington receives over 60 inches of rain a year, yet some areas just east of the Cascade Range receive less than 5 inches. The area east of the Cascade Range (and the Sierra Nevada Range) is said to lie in a rainshadow.

US Precipitation Map


Windward Condensation

Two basic principles in understanding the rainshadow effect are (1) warmer air is able to hold more moisture than colder air and (2) air usually gets colder as one goes up in elevation. When a mass of air comes across the Pacific, it holds a certain amount of moisture, which we cannot see. As it reaches the Pacific Coast Range of the US, it rises. As it rises, it cools. As it cools, the moisture condenses into droplets of water and clouds are formed. As the air mass continues to rise and cool, the droplets get bigger and rain falls. This process is repeated for the same mass of air as it rises up the Cascade and Sierra Nevada Ranges.

Leeward Evaporation

After the parcel of air reaches the peaks of the Cascades and Sierra Nevadas, it descends into warmer temperatures. As the mass of air heats up, it expands and is, therefore, able to hold more moisture. Water droplets in the clouds quickly evaporate and the clouds disappear. Not only have the clouds evaporated, but the total amount of moisture in the air mass is much less because so much was squeezed out on the windward side of the mountain ranges. The downwind side of a mountain is known as the "lee" or "leeward" side.

Because of the Cascades and Sierra Nevada Mountain Ranges, the entire Mountain West region lies in a leeward rainshadow. This causes the West Coast latitudinal desert area to extend much farther northward in the western US than it would otherwise do. (If the mountain ranges were not there, the wet Pacific climate would extend far inland, as it does in Europe.)

Annual Solar Radiation Map - Source: US Solar Radiation Resource Maps* - this website allows you to select maps for every month and for different solar collector panel types and orientations -- the map below is for a flat solar panel tilted toward the south.


Altitudinal Zonation

The fact that higher elevations are cooler and, therefore, are more likely to receive precipitation than lower elevations has a significant impact on the climate of mountainous areas. The high mountains of the West exhibit a wide range of climates and associated vegetation as one moves from low to high elevations. This phenomenon is known as "altitudinal zonation." The typical zone sequence that one passes through in the Mountain West is
- short grass and desert shrub at lowest elevations
- juniper and pinyon pine marking the lower tree line
- larger ponderosa pine and douglas fir trees higher up slope
- tundra marking the high altitude tree line

The high altitude tree line varies from about the 11,500-foot level in Arizona and New Mexico, to 6,000 feet at the Canadian border.

Altitudinal Zonation/Life Zones


Exotic Rivers

High elevation rain and snowfall are the major sources of water throughout the Mountain West region. The Colorado River, Rio Grande, the Snake River, and the Columbia River all carry large volumes of water from high, snow-capped peaks through dry desert lowlands. When a large river with very few tributaries flows through an arid area, it is referred to as an exotic (nonnative) river.


Irrigation projects tapping into the exotic rivers of the Mountain West create "oases" with some of the richest farmlands in the US. Agriculture consumes 80% of the water that is diverted from western rivers. Urban use of this water is a distant second. Water rights laws in most of the rest of the US require that water diversions do not noticeably diminish the stream flow of a river. In the Mountain West, however, virtually every drop of water can be taken from a river. This is what has happened to the Colorado River, which no longer reaches its former mouth at the Gulf of California.

The Colorado River

The waters of the Colorado River originate mostly in the Front Range of Colorado, above Denver. Some of its waters also come from the Wind River Range in Wyoming, the Wasatch Range in Utah, the San Juan Range in New Mexico, and the White Mountains in Arizona. By 1915, almost all of the rights to the Colorado River had been claimed by the earlier, and more numerous, settlers in California and Arizona. In 1922, the Colorado River Compact was signed, splitting the river's water equally between the lower basin (Arizona and California) and the upper basin (Wyoming, Colorado, Utah, and New Mexico) at Lees Ferry.

The upper basin uses very little of its allotted water, although the state of Colorado has considered transporting some of it over the Front Range for use on the Great Plains. California has long used more than its allotted share of the Colorado River. Massive irrigation aqueducts bring Colorado River waters to southern California and Los Angeles. More recently, the Central Arizona Project has been constructed to ensure that Arizona gets its share of the water, as well. A new river compact signed in the early 1970s decreased the upper basin allotment substantially, allotting some of it to Arizona and California, and a substantial increase to Mexico, although the quality of the water to Mexico remains disputed.

Glen Canyon Dam and Lake Powell

Glen Canyon Dam was built near the Arizona-Utah border to regulate flow and usage between the upper and lower basins. Unfortunately, its location has been plagued with problems. Lake Powell, behind the dam, is rapidly filling up with silt. The porous rocks that line the reservoir have soaked up as much water as the lake itself, and very high rates of evaporation have increased the salinity of the lake's water.



Another important source of western water is underground aquifers. We already discussed the massive Ogallala Aquifer under the Great Plains, which has been depleted by one-fourth in this century. Rates of groundwater depletion are even greater in the Mountain West. Areas of Arizona have experienced water table drops of over 300 feet since 1960, forcing the abandonment of farms. Strict groundwater laws in Arizona were passed in the mid-1980s, but these laws may not be able to address the serious damage already done.

Human Geography of the Mountain West

This discussion of the human settlement geography of the Mountain West focuses on (1) Native Americans and Hispanics in the Southwest, (2) the US-Mexican border, (3) Mormon Utah, and (4) other settlement in the Mountain West.

The Southwest

The Southwest states of Arizona and New Mexico may be hotter in parts than the rest of the Mountain West, but the diversity of their physical landscapes is typical of those found throughout the region. What has really given the Southwest a different identity is its distinctive mixture of three major culture groups: Native American, Hispanic, and northern European American. Native Americans comprise 6.5% of the population combined populations of Arizona and New Mexico, while Hispanics make up 23%. Excluding Alaska, Arizona and New Mexico have the highest proportion of Native Americans of any state in the US, while New Mexico is clearly the most Hispanic. Each of these major groups has been able to maintain a strong ethnic identity in the face of far larger numbers of non-Hispanic Caucasians in both states. Growth rates for both of these minority groups are also much higher than that for the rest of the region's population.

Native Americans

When Europeans first arrived in North America, there were an estimated 5 million Native Americans living in what is today the US and Canada. Most were organized into small tribal groups, each with its own culture and traditions. The word tribe can be defined as any group of people with a shared language, customs, and lineage. The lineage (ancestry) can be either real or mythological.

Settled Agricultural Tribes

Lifestyles and the level of technology practiced varied considerably among different tribes. The Hohokam, who occupied the deserts of southern Arizona until the thirteenth century, built a city of more than 8,000 people and developed an advanced network of irrigation canals for agricultural purposes. Some of these canals are still in use today, long after the Hohokam civilization mysteriously disappeared. Today, the Hopi in Arizona and the Pueblo tribes of New Mexico continue the settled agriculturalist lifestyle and traditions in the Southwest.

Hohokam Settlement Area in Arizona Map


Nomadic Hunting Tribes

Other tribes lived a subsistence nomadic lifestyle, centered on hunting and gathering. As in other parts of the world, the nomadic groups, while less technologically advanced, often exhibited superior military capabilities over settled agriculturalists. The Navajos were a nomadic hunting tribe on the Great Plains before migrating into the Southwest, probably in the fourteenth century. Today they comprise the largest tribe and reservation in the US, with a growing population of over 100,000.

Intertribal Conflicts

Settled agriculturalists worldwide tend to view nomadic peoples as uncivilized and uncultured, while viewing themselves as cultured and prosperous. Nomadic peoples worldwide see themselves as independent and able to endure hardships but stereotype settled agriculturalists as being subservient and weak. These attitudes become particularly hostile where resources are limited, such as in the dry Southwest. Some of these traditional stereotypes and hostilities remain today, despite the major changes that European domination has forced on traditional Native American societies.

European Domination of Native Americans

European expansion into the West exploited hostilities between tribes to divide and conquer them. Other factors that helped in this process included the introduction of exotic diseases (such as small pox and measles), which killed millions of Native Americans, and the sheer number of European immigrants to the US (some 60 million in all), which totally overwhelmed the small number of native peoples.

Native American and European Relations

The early Spanish frequently intermarried with Native Americans and actively (and sometimes very cruelly) tried to integrate them into Spanish society. Northern Europeans, however, preferred to ignore and isolate Native Americans, rather than mix with them. In the extreme, there were even attempts at the genocidal destruction of entire tribes. These efforts, exemplified by the nineteenth-century Indian Wars of General George Armstrong Custer, caused many leaders in the US Congress to be appalled, although they did nothing to stop them.

Indian Reservations

The basic belief held by the majority of European settlers in the US was that cultural differences made it impossible for white people and Indians to live together peacefully. The alternative to genocide, therefore, was the complete separation of Native Americans onto areas of land reserved for their exclusive use. Their status on the reservation is one of limited sovereignty. They are separate nations from the US, but not separate countries. They must abide by the US Constitution, but not by state and local laws. (A "nation" is a political unit based on shared cultural history and traditions and which may or may not be fully autonomous.)

American Indian Lands Map


Acculturation and Development

Once native peoples were on reservations, the US government's policy was to gradually acculturate and assimilate them into the dominant American society. Most of these efforts have totally failed, because of a general lack of respect for Native American traditions and values. Reservations today still have some of the highest poverty rates in the US. Federal budget constraints, however, have increased the pressure for greater economic development on reservations. At the same time, the federal government has backed away from efforts to change Native American culture. These factors have resulted in increasing independence and self-respect on reservations, although they still have a long way to go to overcome past injustices.

Native American 1990 Distribution Map



Spanish Settlement in the Southwest

The Spanish were the first Europeans to explore and settle the Southwest. Driven by legends of the Seven Cities of Gold, they came up from their core area in central Mexico, seeking riches, which they did not find. In 1610, they established the settlement of Santa Fe, in what is now New Mexico. By 1700, the first settlements in Arizona and Texas were established. The missions and presidios (military settlements) in California did not come until after 1769, when the first mission at San Diego was founded. The California settlements were primarily intended to protect Spain's interests from the growing presence of Russian and British settlers in California.

American and Mexican Relations

Americans did not arrive in the Spanish Southwest in significant numbers from the East until the 1820s and 1830s. They were allowed to settle on what had by then become Mexican land (after Mexico gained its independence from Spain in 1821). American settlers, however, had no allegiance to the Mexican government, most could not speak Spanish, and many ignored Mexican laws. This resulted in the American settler's seceding Texas from Mexico in 1836, and similar sentiments arose in California and the Southwest. Sensitive to its foreign relations with Mexico, the US did not admit Texas as a state until 1845. In 1846, the US government initiated efforts to buy California and the New Mexico territory from Mexico, but was rebuffed.

The Mexican-American War

The Mexican government's refusal to sell California and the New Mexico territory, and the US government's admittance of Texas as a state, led to the outbreak of the Mexican-American War in 1846. (Note that this is also known as the US-Mexican War.) American troops initiated the conflict by occupying Point Isabel, on the Mexican side of the mouth of the Rio Grande, which prompted an attack by Mexican troops. Almost 14,000 of the 104,600 US troops that fought in the war died, many from yellow fever. This was the highest death rate of any war that the US has ever engaged in. The war ended in 1848 with the Treaty of Guadalupe-Hidalgo. Mexico was forced to cede the northern two-fifths of their country to the US. The Mexican Cession included all of modern-day California, Nevada, Utah, Arizona, and New Mexico, and portions of Colorado, Wyoming, Kansas, and Oklahoma. The US gave the impoverished and bitter Mexican government $15 million in reparations and assumed responsibility for $3 million in claims by US citizens against Mexico. At the time that the US received the Mexican Cession, most of the people living there were Mexicans. Two years later, only 10% of the population was Mexican.

Hispanic Populations in the Southwest Today

The Hispanic population in the Southwest has increased dramatically since the 1960s. Hispanics were the fastest growing population in the US in the 1980s, with a growth rate of over 35%, or five times faster than any other group. In 1990, they comprised 40% of the population of New Mexico, 26% of Texas, 26% of California, and 20% of Arizona. In Los Angeles, there are more Guatemalans and El Salvadorans than in any other city in the world, except Guatemala City and San Salvador. At current growth levels, Hispanics will become the predominant ethnic group in California, Texas, Arizona, Colorado, New Mexico, and New York in the twenty-first century and are projected to comprise 24.5% of the US population by the year 2050.

Hispanic Distribution - 1990



Illegal Immigration

Not all of the Hispanics that come to the US are legally counted in the population figures of the US Bureau of the Census. Between 1980 and 1984, over a million illegal immigrants a year were captured by the US government. Two to four times that number are estimated to have not been caught. About one-half of the illegal immigrants apprehended are Mexican nationals. The rest come from more than 70 other nations from every corner of the globe. The number of apprehensions declined by over one-third after the US government initiated an amnesty program and tough employment laws in 1988.

The Tortilla Curtain

The 1,900-mile-long border between the US and Mexico is the most heavily crossed border in the world, with over 1 million legal crossings a day. It is also one of only two places in the world where a developed Western democracy comes into direct contact with a less developed, traditional country. (The other place is at the European border of Turkey. The differences between Turkey and Greece, however, are less dramatic than those between the US and Mexico.) Because of the stark difference in economics and culture that exists on each side of the US-Mexican border, it has been referred to as the "Tortilla Curtain."

Mexicans in the US

Mexicans come to the US on a daily basis for a variety of reasons, including schooling, shopping, and work. Through an agreement with the US, some Mexican children attend nearby schools in the US. American stores are often perceived by Mexicans to have higher-quality goods than those in Mexico. This is particularly true for electronics products, which are also more expensive in Mexico, due to higher import duties. Some of the small shops on the US side of the border have the highest sales per floor area in the entire US. These same shops are easily affected by problems in the Mexican economy, which can affect their sales.

In the late 1800s, after Mexico lost its northern territory, many Mexicans came across the border to work on the transcontinental railroads that were being built to tie the expanding US together. For most of the twentieth century, Mexicans have come across the border both legally and illegally to work as farm laborers. The below minimum wage scales that these workers received has helped keep US agricultural products (especially fruits and vegetables) relatively inexpensive.

New Mexico Map - National Park Service


Americans in Mexico

Many American tourists cross the border into Mexico to glimpse and experience a different culture, or for recreation at coastal resorts and beaches. Others cross for specific shopping purposes. Leather goods, dental care, prescription drugs, upholstery, and auto body work are all perceived to be less expensive in Mexico.

American businesses also cross the border in search of cheap labor. Under special agreements, American companies are allowed to set up factories in Mexico and then bring the finished products into the US for packaging without paying import duties. These types of factories, known as maquiladoros, have made northern Mexico the wealthiest and fastest growing part of the country. Workers, however, receive only about US$4.00 a day, which is less than in many Asian countries. Cotton and textile factories were the first to migrate to Mexico (from the South, where they had migrated to from their original location in New England). Today, however, most of the maquiladoros manufacture electronics goods and clothing. In 1988, there were 1,250 maquiladoros, with 250 new ones established that year alone. At the urging of the Mexican government, they have also begun moving farther from the border into central Mexico.

US-Mexican Complimentarity

"Complimentarity" in geography refers to situations where two different places contribute to and benefit one another. The US has historically helped Mexico by providing an outlet for its high unemployment and population growth. Mexico, on the other hand, has historically helped the US by providing a source of cheap labor. In this way, geographers would say that there is a high degree of complimentarity between the US and Mexico.


The North American Free Trade Agreement came into effect at the beginning of 1994. This treaty among the US, Canada, and Mexico is designed to gradually lower trade barriers among the three countries and eventually create a single market for goods and services. States located along the US-Mexican border are likely to be the most affected by the NAFTA trade laws. Initial reports for the first six months of 1994 show that trade between the three NAFTA countries has increased considerably. US exports to Mexico rose 17 percent, while those to Canada increased 10 percent. US imports from Mexico increased 21 percent, with a 10 percent increase in exports from Canada. This translates into a net gain of almost 50,000 new jobs in the US during the first six months of 1994.

Northern European Settlement

According to the US Bureau of the Census, the classification of "Hispanic" can be applied to any race. Caucasians (mostly of European decent) who are not Hispanic fall under the "non-Hispanic Caucasian" classification. Because the terminology is somewhat awkward, this text has been referring to this group as "northern Europeans," or people of "northern European ancestry." This group has been more widespread in their settlement throughout the Mountain West than the Spanish, and they have had a greater impact on the environment of the Mountain West than have either the Spanish or Native Americans.

The Mormons

Members of the Church of Jesus Christ of Latter-Day Saints (LDS), known less formally as the Mormon Church, were the first major group of people from the northern European East Coast of the US to settle in the Mountain West region. The LDS religion originated in upstate New York in 1830. The text from which they gain spiritual guidance is the Book of Mormon, which was revealed to and translated by Joseph Smith and is considered along with the rest of the Bible. It describes the settlement of North America by a group of people from the dispersed workers of the Tower of Babel, along with Hebrews who also subsequently migrated across the Atlantic. Although the LDS religion comes out of the same traditions as Judaism, Christianity, and Islam, it is as distinct from any of these religions as they are from one another.

Mormon Migration to Utah

The LDS religion grew rapidly after 1830, in part because of a strong emphasis on proselytizing. However, the Mormons experienced much persecution for their divergent beliefs and economic strength and were forced to relocate several times. In 1847, lead by Brigham Young, a large group of Mormons settled in the Wasatch Valley of Utah, with the intent of creating a new and independent country. Polygamy (plural wives) was introduced at this time to compensate families for the loss of many male heads of households during the westward migration. As a condition for the admission of Utah as a US state, the LDS Church banned polygamy in 1890, although it is still practiced by offshoot groups in some rural areas in Utah and the border regions of neighboring states. In 1869, the first transcontinental railroad was completed with spurs from Sacramento (California) and St. Louis (Missouri) meeting in the Wasatch Valley, just northwest of Salt Lake City.

Mormon Trail, Oregon Trail, and California Trail Map


Mormon Trail Map


Mormon Agriculture

The Mormon settlers were the first Americans of northern European descent to develop agricultural practices that were adapted to the arid West. Most important in this effort was the creation and management of large scale irrigation projects. Such projects were unknown and unnecessary in the humid East. LDS Church members built storage dams in the Wasatch Mountains to collect and hold runoff, which was later released into canals leading to dry lowland crops. Because the LDS Church hierarchy is highly centralized, they were better able to manage such a large irrigation system. As the demand for large scale irrigation projects grew in other parts of the Mountain West, the US government became increasingly involved to both finance and manage these projects.

Mormons Today

Today, there are an estimated 1.5 million LDS Church members out of the more than 10 million people in the Mountain West region. Three out of four live in Utah, and they form the majority of the population of southern Idaho. Sizeable populations are also found in those parts of Arizona, Nevada, Colorado, and Wyoming, which border Utah. Although the LDS Church is still small compared with the major world religions, the importance of proselytizing missionary work makes the Church of Jesus Christ of Latter-Day Saints among the fastest growing in the world.


Utah State Map - National Park Service



Four Corners Map


Other Settlement in the Mountain West

Like the agricultural Wasatch Valley, most settlement in the Mountain West was highly specialized, based on the special opportunities which a specific place might provide. Where water was available, major agricultural communities developed, such as Phoenix on the Salt and Gila Rivers. Mining communities next to copper, gold, silver, and uranium deposits often experienced boom and bust economic cycles. Lumber towns, located at higher elevations, also experienced uneven economies due to fluctuations in the demand and price for wood. Broad areas of arid landscapes isolated these early settlements. Even today, people living in the Mountain West are accustomed to having to travel long distances (200 miles is common) for higher-order goods and services. Many of the old mining and lumber towns, often located in scenic mountain areas, today rely on tourism and recreation to supplement their economies.

Arizona State Map - National Park Service


Return to Top