Colorado Plateau

The Colorado Plateau, also known as the Colorado Plateau Province,[1] 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 of 336, 700 km2 (130,000 mi2) within western Colorado, northwestern New Mexico, southern and eastern Utah, and northern Arizona. About 90% of the area is drained by the Colorado River and its main tributaries: the Green, San Juan, and Little Colorado. Most of the remainder of the plateau is drained by the Rio Grande and its tributaries.[2][3]:395

The Colorado Plateau is largely made up of high desert, with scattered areas of forests. In the southwest corner of the Colorado Plateau lies the Grand Canyon of the Colorado River. Much of the Plateau's landscape is related, in both appearance and geologic history, to the Grand Canyon. The nickname "Red Rock Country" suggests the brightly colored rock left bare to the view by dryness and erosion. Domes, hoodoos, fins, reefs, river narrows, natural bridges, and slot canyons are only some of the additional features typical of the Plateau.

The Colorado Plateau has the greatest concentration of U.S. National Park Service (NPS) units in the country outside the Washington, DC metropolitan area. Among its nine National Parks are Grand Canyon, Zion, Bryce Canyon, Capitol Reef, Canyonlands, Arches, Mesa Verde, and Petrified Forest. Among its 18 National Monuments are Bears Ears, Rainbow Bridge, Dinosaur, Hovenweep, Wupatki, Sunset Crater Volcano, Grand Staircase-Escalante, Natural Bridges, Canyons of the Ancients, Chaco Culture National Historical Park and the Colorado National Monument.

Colorado Plateaus map
A map of the Colorado Plateau.
Four Corners Monument (1)
The Four Corners Monument is where the states of Colorado, New Mexico, Arizona, and Utah meet. (The states are listed in clockwise order.)

Geography

Four corners
The Four Corners region and the Colorado Plateau. Click image to see state lines.
Grand Junction Trip 92007 012
The Book Cliffs of western Colorado.
Green River, eastern Utah
The Green River runs north to south from Wyoming, briefly through Colorado, and converges with the Colorado River in southeastern Utah.
Sunset in Ojito Wilderness, NM
Sunset in Ojito Wilderness, near Albuquerque, NM

This province is bounded by the Rocky Mountains in Colorado, and by the Uinta Mountains and Wasatch Mountains branches of the Rockies in northern and central Utah. It is also bounded by the Rio Grande Rift, Mogollon Rim and the Basin and Range Province. Isolated ranges of the Southern Rocky Mountains such as the San Juan Mountains in Colorado and the La Sal Mountains in Utah intermix into the central and southern parts of the Colorado Plateau. It is composed of six sections:[3]:367

As the name implies, the High Plateaus Section is, on average, the highest section. North-south trending normal faults that include the Hurricane, Sevier, Grand Wash, and Paunsaugunt separate the section's component plateaus.[3]:366 This fault pattern is caused by the tensional forces pulling apart the adjacent Basin and Range province to the west, making this section transitional.

Occupying the southeast corner of the Colorado Plateau is the Datil Section. Thick sequences of mid-Tertiary to late-Cenozoic-aged lava covers this section.

Development of the province has in large part been influenced by structural features in its oldest rocks. Part of the Wasatch Line and its various faults form the western edge of the province. Faults that run parallel to the Wasatch Fault that lies along the Wasatch Range form the boundaries between the plateaus in the High Plateaus Section.[3]:376 The Uinta Basin, Uncompahgre Uplift, and the Paradox Basin were also created by movement along structural weaknesses in the region's oldest rock.

In Utah, the province includes several higher fault-separated plateaus:

Some sources also include the Tushar Mountain Plateau as part of the Colorado Plateau, but others do not. The mostly flat-lying sedimentary rock units that make up these plateaus are found in component plateaus that are between 4,900 to 11,000 feet (1,500 to 3,350 m) above sea level. A supersequence of these rocks is exposed in the various cliffs and canyons (including the Grand Canyon) that make up the Grand Staircase. Increasingly younger east-west trending escarpments of the Grand Staircase extend north of the Grand Canyon and are named for their color:

Within these rocks are abundant mineral resources that include uranium, coal, petroleum, and natural gas. Study of the area's unusually clear geologic history (which is laid bare due to the arid and semiarid conditions) has greatly advanced that science.

A rain shadow from the Sierra Nevada far to the west and the many ranges of the Basin and Range means that the Colorado Plateau receives six to sixteen inches (15 to 40 cm) of annual precipitation.[3]:369 Higher areas receive more precipitation and are covered in forests of pine, fir, and spruce.

Though it can be said that the Plateau roughly centers on the Four Corners, Black Mesa in northern Arizona is much closer to the east-west, north-south midpoint of the Plateau Province. Lying southeast of Glen Canyon and southwest of Monument Valley at the north end of the Hopi Reservation, this remote coal-laden highland has about half of the Colorado Plateau's acreage north of it, half south of it, half west of it, and half east of it.

Human history

The Ancestral Puebloan People lived in the region from roughly 2000 to 700 years ago.[3]:374

A party from Santa Fe led by Fathers Dominguez and Escalante, unsuccessfully seeking an overland route to California, made a five-month out-and-back trip through much of the Plateau in 1776-1777.[4]

Despite having lost one arm in the American Civil War, U.S. Army Major and geologist John Wesley Powell explored the area in 1869 and 1872. Using wooden oak boats and small groups of men the Powell Geographic Expedition charted this largely unknown region of the United States for the federal government.

Construction of the Hoover Dam in the 1930s and the Glen Canyon Dam in the 1960s changed the character of the Colorado River. Dramatically reduced sediment load changed its color from reddish brown (Colorado is Spanish for "red") to mostly clear. The apparent green color is from algae on the riverbed's rocks, not from any significant amount of suspended material. The lack of sediment has also starved sand bars and beaches but an experimental 12-day-long controlled flood from Glen Canyon Dam in 1996 showed substantial restoration. Similar floods are planned for every 5 to 10 years.[3]:375

Geology

Colorado Plateau, Mojave desert
The Redwall Limestone cliffs of the Colorado Plateau tower above the northern Mojave Desert.
SEUtahStrat
The Permian through Jurassic stratigraphy of the Colorado Plateau area of southeastern Utah that makes up much of the famous prominent rock formations in protected areas such as Capitol Reef National Park and Canyonlands National Park. From top to bottom: Rounded tan domes of the Navajo Sandstone, layered red Kayenta Formation, cliff-forming, vertically jointed, red Wingate Sandstone, slope-forming, purplish Chinle Formation, layered, lighter-red Moenkopi Formation, and white, layered Cutler Formation sandstone. Picture from Glen Canyon National Recreation Area, Utah.
Dirty devil river
Erosion-resistant sandstones of Mesozoic age result in bands of continuous cliffs, central Colorado Plateau.
MODIS1000013
MODIS satellite image of Grand Canyon, Lake Powell (black, left of center) and the Colorado Plateau. White areas are snow-capped.

One of the most geologically intriguing features of the Colorado Plateau is its remarkable stability. Relatively little rock deformation such as faulting and folding has affected this high, thick crustal block within the last 600 million years or so. In contrast, provinces that have suffered severe deformation surround the plateau. Mountain building thrust up the Rocky Mountains to the north and east and tremendous, earth-stretching tension created the Basin and Range province to the west and south. Sub ranges of the Southern Rocky Mountains are scattered throughout the Colorado Plateau.[5]

The Precambrian and Paleozoic history of the Colorado Plateau is best revealed near its southern end where the Grand Canyon has exposed rocks with ages that span almost 2 billion years. The oldest rocks at river level are igneous and metamorphic and have been lumped together as Vishnu Basement Rocks; the oldest ages recorded by these rocks fall in the range 1950 to 1680 million years. An erosion surface on the "Vishnu Basement Rocks" is covered by sedimentary rocks and basalt flows, and these rocks formed in the interval from about 1250 to 750 million years ago: in turn, they were uplifted and split into a range of fault-block mountains.[3]:383 Erosion greatly reduced this mountain range prior to the encroachment of a seaway along the passive western edge of the continent in the early Paleozoic. At the canyon rim is the Kaibab Formation, limestone deposited in the late Paleozoic (Permian) about 270 million years ago.

A 12,000-to-15,000-foot high (3,700 to 4,600 m) extension of the Ancestral Rocky Mountains called the Uncompahgre Mountains were uplifted and the adjacent Paradox Basin subsided. Almost 4 mi. (6.4 km) of sediment from the mountains and evaporites from the sea were deposited (see geology of the Canyonlands area for detail).[3]:383 Most of the formations were deposited in warm shallow seas and near-shore environments (such as beaches and swamps) as the seashore repeatedly advanced and retreated over the edge of a proto-North America (for detail, see geology of the Grand Canyon area). The province was probably on a continental margin throughout the late Precambrian and most of the Paleozoic era. Igneous rocks injected millions of years later form a marbled network through parts of the Colorado Plateau's darker metamorphic basement. By 600 million years ago North America had been leveled off to a remarkably smooth surface.

Throughout the Paleozoic Era, tropical seas periodically inundated the Colorado Plateau region. Thick layers of limestone, sandstone, siltstone, and shale were laid down in the shallow marine waters. During times when the seas retreated, stream deposits and dune sands were deposited or older layers were removed by erosion. Over 300 million years passed as layer upon layer of sediment accumulated.

It was not until the upheavals that coincided with the formation of the supercontinent Pangea began about 250 million years ago that deposits of marine sediment waned and terrestrial deposits dominate. In late Paleozoic and much of the Mesozoic era the region was affected by a series of orogenies (mountain-building events) that deformed western North America and caused a great deal of uplift. Eruptions from volcanic mountain ranges to the west buried vast regions beneath ashy debris. Short-lived rivers, lakes, and inland seas left sedimentary records of their passage. Streams, ponds and lakes created formations such as the Chinle, Moenave, and Kayenta in the Mesozoic era. Later a vast desert formed the Navajo and Temple Cap formations and dry near-shore environment formed the Carmel (see geology of the Zion and Kolob canyons area for details).

The area was again covered by a warm shallow sea when the Cretaceous Seaway opened in late Mesozoic time. The Dakota Sandstone and the Tropic Shale were deposited in the warm shallow waters of this advancing and retreating seaway. Several other formations were also created but were mostly eroded following two major periods of uplift.

The Laramide orogeny closed the seaway and uplifted a large belt of crust from Montana to Mexico, with the Colorado Plateau region being the largest block. Thrust faults in Colorado are thought to have formed from a slight clockwise movement of the region, which acted as a rigid crustal block. The Colorado Plateau Province was uplifted largely as a single block, possibly due to its relative thickness. This relative thickness may be why compressional forces from the orogeny were mostly transmitted through the province instead of deforming it.[3]:376 Pre-existing weaknesses in Precambrian rocks were exploited and reactivated by the compression. It was along these ancient faults and other deeply buried structures that much of the province's relatively small and gently inclined flexures (such as anticlines, synclines, and monoclines) formed.[3]:376 Some of the prominent isolated mountain ranges of the Plateau, such as Ute Mountain and the Carrizo Mountains, both near the Four Corners, are cored by igneous rocks that were emplaced about 70 million years ago.

Minor uplift events continued through the start of the Cenozoic era and were accompanied by some basaltic lava eruptions and mild deformation. The colorful Claron Formation that forms the delicate hoodoos of Bryce Amphitheater and Cedar Breaks was then laid down as sediments in cool streams and lakes (see geology of the Bryce Canyon area for details). The flat-lying Chuska Sandstone was deposited about 34 million years ago; the sandstone is predominantly of eolian origin and locally more than 500 meters thick. The Chuska Sandstone caps the Chuska mountains, and it lies unconformably on Mesozoic rocks deformed during the Laramide orogeny.

Younger igneous rocks form spectacular topographic features. The Henry Mountains, La Sal Range, and Abajo Mountains, ranges that dominate many views in southeastern Utah, are formed about igneous rocks that were intruded in the interval from 20 to 31 million years: some igneous intrusions in these mountains form laccoliths, a form of intrusion recognized by Grove Karl Gilbert during his studies of the Henry Mountains. Ship Rock (also called Shiprock), in northwestern New Mexico, and Church Rock and Agathla, near Monument Valley, are erosional remnants of potassium-rich igneous rocks and associated breccias of the Navajo Volcanic Field, produced about 25 million years ago. The Hopi Buttes in northeastern Arizona are held up by resistant sheets of sodic volcanic rocks, extruded about 7 million years ago. More recent igneous rocks are concentrated nearer the margins of the Colorado Plateau. The San Francisco Peaks near Flagstaff, south of the Grand Canyon, are volcanic landforms produced by igneous activity that began in that area about 6 million years ago and continued until 1064 C.E., when basalt erupted in Sunset Crater National Monument. Mount Taylor, near Grants, New Mexico, is a volcanic structure with a history similar to that of the San Francisco Peaks: a basalt flow closer to Grants was extruded only about 3000 years ago (see El Malpais National Monument). These young igneous rocks may record processes in the Earth's mantle that are eating away at deep margins of the relatively stable block of the Plateau.

Tectonic activity resumed in Mid Cenozoic time and started to unevenly uplift and slightly tilt the Colorado Plateau region and the region to the west some 20 million years ago (as much as 3 kilometers of uplift occurred). Streams had their gradient increased and they responded by downcutting faster. Headward erosion and mass wasting helped to erode cliffs back into their fault-bounded plateaus, widening the basins in-between. Some plateaus have been so severely reduced in size this way that they become mesas or even buttes. Monoclines form as a result of uplift bending the rock units. Eroded monoclines leave steeply tilted resistant rock called a hogback and the less steep version is a cuesta.

The Three Patriarchs in Zion Canyon
Cliffs of Navajo Sandstone in Zion National Park

Great tension developed in the crust, probably related to changing plate motions far to the west. As the crust stretched, the Basin and Range province broke up into a multitude of down-dropped valleys and elongate mountains. Major faults, such as the Hurricane Fault, developed that separate the two regions. The dry climate was in large part a rainshadow effect resulting from the rise of the Sierra Nevada further west. Yet for some reason not fully understood, the neighboring Colorado Plateau was able to preserve its structural integrity and remained a single tectonic block.[5]

A second mystery was that while the lower layers of the Plateau appeared to be sinking, overall the Plateau was rising. The reason for this was discovered upon analyzing data from the USARRAY project. It was found that the asthenosphere had invaded the overlying lithosphere, as a result of an area of mantle upwelling stemming from either the disintegration of the descending Farallon Plate, or the survival of the subducted spreading center connected to the East Pacific Rise and Gorda Ridge beneath western North America, or possibly both. The asthenosphere erodes the lower levels of the Plateau. At the same time, as it cools, it expands and lifts the upper layers of the Plateau.[6] Eventually, the great block of Colorado Plateau crust rose a kilometer higher than the Basin and Range. As the land rose, the streams responded by cutting ever deeper stream channels. The most well-known of these streams, the Colorado River, began to carve the Grand Canyon less than 6 million years ago.[5]

The Pleistocene epoch brought periodic ice ages and a cooler, wetter climate. This increased erosion at higher elevations with the introduction of alpine glaciers while mid-elevations were attacked by frost wedging and lower areas by more vigorous stream scouring. Pluvial lakes also formed during this time. Glaciers and pluvial lakes disappeared and the climate warmed and became drier with the start of Holocene epoch.

Energy generation

Coal Mine in Carbon County, Utah
Coal mine in Carbon County, UT.

Electrical power generation is one of the major industries that takes place in the Colorado Plateau region. Most electrical generation comes from coal fired power plants.

Natural resources

Petroleum

The rocks of the Colorado Plateau are a source of oil and a major source of natural gas. Major petroleum deposits are present in the San Juan Basin of New Mexico and Colorado, the Uinta Basin of Utah, the Piceance Basin of Colorado, and the Paradox Basin of Utah, Colorado, and Arizona.

Uranium

The Colorado Plateau holds major uranium deposits, and there was a uranium boom in the 1950s. The Atlas Uranium Mill near Moab has left a problematic tailings pile for cleanup, which is soon to happen.

Coal

Major coal deposits are being mined in the Colorado Plateau in Utah, Arizona, Colorado, and New Mexico, though large coal mining projects, such as on the Kaiparowits Plateau, have been proposed and defeated politically. The ITT Power Project, eventually located in Lynndyl, Utah, near Delta, was originally suggested for Salt Wash near Capitol Reef National Park. After a firestorm of opposition, it was moved to a less beloved site. In Utah the largest deposits are in aptly named Carbon County. In Arizona the biggest operation is on Black Mesa, supplying coal to Navajo Power Plant.

Gilsonite and uintaite

Perhaps the only one of its kind, a gilsonite plant near Bonanza, southeast of Vernal, Utah, mines this unique, lustrous, brittle form of asphalt, for use in "varnishes, paints,...ink, waterproofing compounds, electrical insulation,...roofing materials."[7]

Scenic beauty

The scenic appeal of this unique landscape had become, well before the end of the twentieth century, its greatest financial natural resource. The amount of commercial benefit to the four states of the Colorado Plateau from tourism exceeded that of any other natural resource.

Protected lands

Lake Powell Above Wahweap Marina
Erosional features within Glen Canyon National Recreation Area.

This relatively high semi-arid province produces many distinctive erosional features such as arches, arroyos, canyons, cliffs, fins, natural bridges, pinnacles, hoodoos, and monoliths that, in various places and extents, have been protected. Also protected are areas of historic or cultural significance, such as the pueblos of the Anasazi culture. There are nine U.S. National Parks, a National Historical Park, sixteen U.S. National Monuments and dozens of wilderness areas in the province along with millions of acres in U.S. National Forests, many state parks, and other protected lands. In fact, this region has the highest concentration of parklands in North America.[3]:365 Lake Powell, in foreground, is not a natural lake but a reservoir impounded by Glen Canyon Dam.

National parks (from south to north to south clockwise):

National monuments (alphabetical):

Wilderness areas (alphabetical):

Other notable protected areas include: Barringer Crater, Dead Horse Point State Park, Glen Canyon National Recreation Area, Goblin Valley State Park, Goosenecks State Park, the Grand Gulch Primitive Area, Kodachrome Basin State Park, Monument Valley, and the San Rafael Swell.

Sedona, Arizona and Oak Creek Canyon lie on the south-central border of the Plateau. Many but not all of the Sedona area's cliff formations are protected as wilderness. The area has the visual appeal of a national park, but with a small, rapidly growing town in the center.

See also

References

  1. ^ "Colorado Plateau | plateau, United States". Encyclopædia Britannica. Retrieved 2017-06-05.
  2. ^ Leighty, Robert D. (2001). "Colorado Plateau Physiographic Province". Contract Report. Defense Advanced Research Projects Agency (DOD) Information Sciences Office. Archived from the original on 2004-09-26. Retrieved 2007-12-25.
  3. ^ a b c d e f g h i j k l m Kiver, Eugene P.; Harris, David V. (1999). Geology of U.S. Parklands (5th ed.). John Wiley & Sons. ISBN 0-471-33218-6.
  4. ^ Crampton, Gregory (1964). Standing Up Country. New York: Alfred Knopf. pp. 43–46.
  5. ^ a b c  This article incorporates public domain material from the United States Geological Survey document: "Colorado Plateau Province". Geologic Provinces of the United States. Retrieved 2017-07-04.
  6. ^ "Why is the Colorado Plateau Rising?". Geology.com. Archived from the original on 2011-05-05. Retrieved 9 May 2011.
  7. ^ Utah: A Guide to the State. 1982. p. 590.

Further reading

Grandjunctionalpineloop 032
Prickly pear cactus are common throughout the Colorado Plateau region.
  • Baars, Donald L. (1972). Red Rock Country: The Geologic History of the Colorado Plateau. Doubleday. ISBN 0-385-01341-8.
  • Baars, Donald L. (2002). Traveler's Guide to the Geology of the Colorado Plateau. University of Utah Press. ISBN 0-87480-715-8.
  • Baldridge, W. Scott (2004). Geology of the American Southwest: A Journey Through Two Billion Years of Plate-Tectonic History. Cambridge University Press. ISBN 0-521-01666-5.
  • Fillmore, Robert (2011). Geological Evolution of the Colorado Plateau of Eastern Utah and Western Colorado. University of Utah Press. ISBN 978-1-60781-004-9.
  • Harris, Ann G.; Tuttle, Esther; Tuttle, Sherwood D. (1997). Geology of National Parks (Fifth ed.). Iowa: Kendall/Hunt Publishing. pp. 2–3, 19–20, 25. ISBN 0-7872-5353-7.
  • Plummer, Charles C.; McGeary, David; Carlson, Diane H. (1999). Physical Geology (Eighth ed.). Boston: McGraw-Hill. p. 320. ISBN 0-697-37404-1.
  • Stanley, Steven M. (1999). Earth System History. W.H. Freeman and Company. pp. 511–513, 537. ISBN 0-7167-2882-6.
  • Foos, Annabelle. Geology of the Colorado Plateau (PDF). National Park Service. Archived from the original (PDF) on 2004-06-10. Retrieved 2005-12-21.
  • Roylance, Ward (1982). Utah: A Guide to the State. Salt Lake City: Utah: A Guide to the State Foundation. OL 3508093M.
  • Look, Al (1947). A Thousand Million Years on the Colorado Plateau. Golden Bell Publications. OCLC 254673147.
  • Trimble, Stephen (1979). The Bright Edge: A Guide to the National Parks of the Colorado Plateau. Museum of Northern Arizona Press. OCLC 768218015.

Coordinates: 37°N 110°W / 37°N 110°W

Agathla Peak

Agathla Peak (Navajo: Aghaałą́, Spanish: El Capitan) is a peak south of Monument Valley, Arizona, which rises over 1500 feet (457 meters) above the surrounding terrain. It is 7 miles (11 km) north of Kayenta and is visible from U.S. Route 163. The English designation Agathla is derived from the Navajo name aghaałą́ meaning 'much wool', apparently for the fur of antelope and deer accumulating on the rock. The mountain is considered sacred by the Navajo.

Agathla Peak is an eroded volcanic plug consisting of volcanic breccia cut by dikes of an unusual igneous rock called minette. It is one of many such volcanic diatremes that are found in Navajo country of northeast Arizona and northwest New Mexico. Agathla Peak and Shiprock in New Mexico are the most prominent. These rocks are part of the Navajo Volcanic Field, in the southern Colorado Plateau. Ages of these minettes and associated more unusual igneous rocks cluster near 25 million years.

Arches National Park

Arches National Park is a national park in eastern Utah, United States. The park is adjacent to the Colorado River, 4 miles (6 km) north of Moab, Utah. More than 2,000 natural sandstone arches are located in the park, including the well-known Delicate Arch, as well as a variety of unique geological resources and formations. The park contains the highest density of natural arches in the world.The park consists of 76,679 acres (119.811 sq mi; 31,031 ha; 310.31 km2) of high desert located on the Colorado Plateau. The highest elevation in the park is 5,653 feet (1,723 m) at Elephant Butte, and the lowest elevation is 4,085 feet (1,245 m) at the visitor center. The park receives an average of less than 10 inches (250 mm) of rain annually.

Administered by the National Park Service, the area was originally named a national monument on April 12, 1929, and was redesignated as a national park on November 12, 1971. The park received more than 1.6 million visitors in 2018.

Beaver Dam Mountains Wilderness

The Beaver Dam Mountains Wilderness is a wilderness area located in northwestern Arizona and southwestern Utah, USA, within the arid Colorado Plateau region. The jagged mountains and gently sloping alluvial plain of the Beaver Dam Mountains straddle the border between the two states. The Wilderness contains some of the lowest elevation land in Utah, and includes a 13 miles (21 km) section of the Virgin River Gorge. The area comprises some 18,667 acres (7,554 ha), 15,000 acres (6,100 ha) of which in Arizona and approximately 3,667 acres (1,484 ha) in Utah. The area was designated Wilderness by the U.S. Congress in 1984 and is administered by the Bureau of Land Management.

The Mojave Desert landscape of the Beaver Dam Mountains features multitudes of Joshua trees (Yucca brevifolia). Notable wildlife include desert bighorn sheep, the threatened desert tortoise, and large numbers of raptors. South of Beaver Dam lies the Paiute Wilderness, on the other side of the Interstate 15 corridor and lying partially inside Grand Canyon-Parashant National Monument.

Book Cliffs

The Book Cliffs are a series of desert mountains and cliffs in western Colorado and eastern Utah, in the western United States. They are so named because the cliffs of Cretaceous sandstone that cap many of the south-facing buttes appear similar to a shelf of books.

Chuska Mountains

The Chuska Mountains are an elongate range on the southeast Colorado Plateau and within the Navajo Nation whose highest elevations approach 10,000 feet. The range is about 80 by 15 km (50 by 10 miles). It trends north-northwest and is crossed by the state line between Arizona and New Mexico. The highlands are a dissected plateau, with an average elevation of about 2,740 m (8,990 ft), and subdued topography. The highest point is Roof Butte (36.4601° N, 109.0929° W) at 2,994 m (9,823 ft), near the northern end of the range in Arizona. Other high points include the satellite Beautiful Mountain at 2,861 m (9,386 ft) and Lukachukai Mountains at 2,885 m (9,465 ft), both also near the northern end, and Matthews Peak at 2,911 m (9,551 ft). The San Juan Basin borders the Chuskas on the east, and typical elevations in nearby parts of that basin are near 1,800 m (5,900 ft). The eastern escarpment of the mountains is marked by slumps and landslides that extend out onto the western margin of the San Juan Basin. To the north, the Chuskas are separated from the Carrizo Mountains by Red Rock Valley, which is today commonly referred to as Red Valley.

Coconino Plateau

The Coconino Plateau is found south of the Grand Canyon and north-northwest of Flagstaff, in northern Arizona of the Southwestern United States.

Four Corners

The Four Corners is a region of the United States consisting of the southwestern corner of Colorado, southeastern corner of Utah, northeastern corner of Arizona, and northwestern corner of New Mexico. The Four Corners area is named after the quadripoint at the intersection of approximately 37° north latitude with 109° 03' west longitude, where the boundaries of the four states meet, and are marked by the Four Corners Monument. It is the only location in the United States where four states meet. Most of the Four Corners region belongs to semi-autonomous Native American nations, the largest of which is the Navajo Nation, followed by Hopi, Ute, and Zuni tribal reserves and nations. The Four Corners region is part of a larger region known as the Colorado Plateau and is mostly rural, rugged, and arid. In addition to the monument, commonly visited areas within Four Corners include Monument Valley, Mesa Verde National Park, Chaco Canyon, Canyons of the Ancients National Monument and Canyon de Chelly National Monument. The most populous city in the Four Corners region is Farmington, New Mexico, followed by Durango, Colorado.

Grand Valley (Colorado-Utah)

The Grand Valley is an extended populated valley, approximately 30 miles (48 km) long and 5 miles (8.0 km) wide, located along the Colorado River in Mesa County (and slightly into Garfield County) in western Colorado and Grand County in eastern Utah in the Western United States. The valley contains the city of Grand Junction, as well as other smaller communities such as Fruita, and Palisade. The valley is noted as a major fruit-growing region, with a large number of orchards. It takes its name from the "Grand River", the historical name of the Colorado River upstream from its confluence with the Green River that was used by locals in the late 19th and early 20th century. The valley is the most densely populated area on the Colorado Western Slope, with Grand Junction serving as an unofficial capital of the region, as a counterpoint to Denver on the eastern slope of the Rocky Mountains in the Colorado Front Range. Interstate 70 and U.S. Highway 6 run through the valley from west-to-east. The Grand Valley is part of the larger Colorado Plateau desert lands.

Kaibab Plateau

The Kaibab Plateau is located in northern Arizona in the United States. The plateau, part of the larger Colorado Plateau, is bordered on the south by the Grand Canyon and reaches an elevation of 9200 feet (2817 m) above sea level. The plateau is divided between Kaibab National Forest and the "North Rim" portion of Grand Canyon National Park. Tributary canyons of the Colorado River form the plateau's eastern and western boundaries, and tiers of uplifted cliffs define the northern edges of the land form. Winter snowfall is often heavy (sometimes exceeding 200 in (5,100 mm)), and this creates opportunities for backcountry Nordic skiing and snow camping.This broad feature is heavily forested with aspen, spruce-fir, ponderosa pine, and pinyon-juniper woodland, and stands in sharp contrast to the arid lowlands encircling it. The cool forests of the plateau are home to the Kaibab squirrel, which is endemic to the region. Other fauna includes deer, turkey, cougar, and bobcat. The Kaibab deer are particularly important because of the changes in their population during the early 1900s. This particular fluctuation is a great example of population engineering and the effects humans can have on nature.

Kokopelli Trail

The Kokopelli's Trail is a 142-mile (229 km) multi-use trail in the Western U.S. states of Colorado and Utah. The trail was named in honor of its mythic muse, Kokopelli. The trail was created by the Colorado Plateau Mountain Bike Trail Association (COPMOBA) in cooperation with the United States Bureau of Land Management (BLM) and the United States Forest Service (NFS) in 1989.

Moenkopi Formation

The Moenkopi Formation is a geological formation that is spread across the U.S. states of New Mexico, northern Arizona, Nevada, southeastern California, eastern Utah and western Colorado. This unit is considered to be a group in Arizona. Part of the Colorado Plateau and Basin and Range, this red sandstone was laid down in the Lower Triassic and possibly part of the Middle Triassic, around 240 million years ago.

Mogollon Plateau

The Mogollon Plateau or Mogollon Mesa ( or ) is a pine-covered southern plateau section of the larger Colorado Plateau in east-central Arizona and west-central New Mexico, United States. The southern boundary of the plateau is the Mogollon Rim. The Mogollon Plateau is 7,000–8,000 feet (2,100–2,400 m) high. The plateau lends its name to the Mogollon tribe, part of the Cochise-Mogollan peoples who inhabited this and nearby areas from 5,000 to 2,500 years ago. Their descendants are believed to include the Anasazi.

Mogollon Rim

The Mogollon Rim ( or or ) is a topographical and geological feature cutting across the U.S. state of Arizona. It extends approximately 200 miles (320 km), starting in northern Yavapai County and running eastward, ending near the border with New Mexico. It forms the southern edge of the Colorado Plateau in Arizona.

Monument Valley

Monument Valley (Navajo: Tsé Biiʼ Ndzisgaii, pronounced [tsʰépìːʔntsɪ̀skɑ̀ìː], meaning valley of the rocks) is a region of the Colorado Plateau characterized by a cluster of vast sandstone buttes, the largest reaching 1,000 ft (300 m) above the valley floor. It is located on the Arizona–Utah border (around 36°59′N 110°6′W), near the Four Corners area. The valley lies within the territory of the Navajo Nation Reservation and is accessible from U.S. Highway 163.

Monument Valley has been featured in many forms of media since the 1930s. Director John Ford used the location for a number of his best-known films and thus, in the words of critic Keith Phipps, "its five square miles [13 square kilometers] have defined what decades of moviegoers think of when they imagine the American West."

Natural Bridges National Monument

Natural Bridges National Monument is a U.S. National Monument located about 50 miles (80 km) northwest of the Four Corners boundary of southeast Utah, in the western United States, at the junction of White Canyon and Armstrong Canyon, part of the Colorado River drainage. It features the thirteenth largest natural bridge in the world, carved from the white Permian sandstone of the Cedar Mesa Formation that gives White Canyon its name.

The three bridges in the park are named Kachina, Owachomo, and Sipapu (the largest), which are all Hopi names. A natural bridge is formed through erosion by water flowing in the stream bed of the canyon. During periods of flash floods, particularly, the stream undercuts the walls of rock that separate the meanders (or "goosenecks") of the stream, until the rock wall within the meander is undercut and the meander is cut off; the new stream bed then flows underneath the bridge. Eventually, as erosion and gravity enlarge the bridge's opening, the bridge collapses under its own weight. There is evidence of at least two collapsed natural bridges within the Monument.

San Francisco volcanic field

The San Francisco volcanic field is an area of volcanoes in northern Arizona, north of Flagstaff, USA. The field covers 1,800 square miles (4,700 km²) of the southern boundary of the Colorado Plateau. The field contains 600 volcanoes ranging in age from nearly 6 million years old to less than 1,000 years (Miocene to Holocene), of which Sunset Crater is the youngest. The highest peak in the field is Humphreys Peak, at Flagstaff's northern perimeter: the peak is Arizona's highest at 12,633 feet (3,851 m) and is a part of the San Francisco Peaks, an extinct stratovolcano complex.

San Rafael Swell

The San Rafael Swell is a large geologic feature located in south-central Utah about 30 miles (48 km) west of Green River, Utah. The San Rafael Swell, measuring approximately 75 by 40 miles (121 by 64 km), consists of a giant dome-shaped anticline of sandstone, shale, and limestone that was pushed up during the Paleocene Laramide Orogeny 60–40 million years ago. Since that time, infrequent but powerful flash floods have eroded the sedimentary rocks into numerous valleys, canyons, gorges, mesas, and buttes. The swell is part of the Colorado Plateau physiographic region.

Uinta Basin

The Uinta Basin (also known as the Uintah Basin) is a physiographic section of the larger Colorado Plateaus province, which in turn is part of the larger Intermontane Plateaus physiographic division. It is also a geologic structural basin in eastern Utah, east of the Wasatch Mountains and south of the Uinta Mountains. The Uinta Basin is fed by creeks and rivers flowing south from the Uinta Mountains. Many of the principal rivers (Strawberry River, Currant Creek, Rock Creek, Lake Fork River, and Uintah River) flow into the Duchesne River which feeds the Green River—a tributary of the Colorado River. The Uinta Mountains forms the northern border of the Uinta Basin. They contain the highest point in Utah, Kings Peak, with a summit 13,528 feet (4123 metres) above sea level.

The climate of the Uinta Basin is semi-arid, with occasionally severe winter cold.

White Mountains (Arizona)

The White Mountains of Arizona are a mountain range and mountainous region in the eastern part of the state, near the border with New Mexico; it is a continuation from the west of the Arizona transition zone–Mogollon Rim, with the Rim ending in western New Mexico. The White Mountains are a part of the Colorado Plateau high country of Northeast Arizona, the Navajo Nation, with the rest of the Plateau in eastern Utah, northwest New Mexico, and southwestern Colorado. Nearby communities include Show Low, Pinetop-Lakeside, Greer, Springerville, Eagar, and McNary. Much of the range is within the Fort Apache Indian Reservation.

The highest summit is Mount Baldy, with an elevation of 11,400 feet (3,475 m).

The mountains are drained to the south by several tributaries of the Salt River, and to the north by the Little Colorado River. There are several small lakes.

The part of the White Mountains outside the reservation is in the Apache-Sitgreaves National Forests.

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