Uinta Mountains

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Uinta Mountains
Kings Peak with Henry's Fork Basin.jpg
This view of Kings Peak and the Henry's Fork Basin shows the cliff bands and basins typical throughout the Uintas.
Highest point
Peak Kings Peak
Elevation 13,528 ft (4,123 m)
Coordinates 40°46′34″N110°22′22″W / 40.776111°N 110.372778°W / 40.776111; -110.372778
Geography
CountryUnited States
StatesUtah and Wyoming
Range coordinates 40°46′N110°35′W / 40.767°N 110.583°W / 40.767; -110.583 Coordinates: 40°46′N110°35′W / 40.767°N 110.583°W / 40.767; -110.583
Parent range Rocky Mountains
Geology
Age of rock Precambrian
Type of rock quartzite, shale and slate

The Uinta Mountains ( /jˈɪntə/ yoo-IN-tə) are an east-west trending chain of mountains in northeastern Utah extending slightly into southern Wyoming in the United States. As a subrange of the Rocky Mountains, they are unusual for being the highest range in the contiguous United States running east to west, [1] and lie approximately 100 miles (160 km) east of Salt Lake City. The range has peaks ranging from 11,000 to 13,528 feet (3,353 to 4,123 m), with the highest point being Kings Peak, also the highest point in Utah. The Mirror Lake Highway crosses the western half of the Uintas on its way to Wyoming.

Contents

Geology

Hayden Peak and Mount Agassiz seen from Bald Mountain Bald Mountain - Uintahs (CCBYSA).jpg
Hayden Peak and Mount Agassiz seen from Bald Mountain

The Uinta Mountains are Laramide uplifted metasedimentary rocks deposited in an intracratonic basin in southwest Laurentia during the time of the breakup of the supercontinent Rodinia. The marine and fluvial metasedimentary rocks in the core of the Uinta Mountains are of Neoproterozoic age [2] (between about 700 million and 800 million years old) and consist primarily of quartzite, slate, and shale. These rocks comprise the Uinta Mountain Group, and reach thicknesses of 13,000 to 24,000 feet (4.0 to 7.3 km). Most of the high peaks are outcrops of the Uinta Mountain Group. Many of the peaks are ringed with bands of cliffs, rising to form broad or flat tops. [3] The mountains are bounded to the north and south by reverse faults that meet below the range, on the north by the North Flank fault and on the south by the Uinta Basin boundary fault. [4]

The Uinta Mountain Group from oldest to youngest includes Uinta Mountain undivided quartz arenite, overlain by the Moosehorn Lake, Mount Watson, Hades Peak, and Red Shale formations. [5] The flanks of the east-west trending Uinta Mountains contain a sequence of Paleozoic and Mesozoic strata ranging from the Cambrian Lodore Formation to the Cretaceous Mancos Shale, all of which have been tilted during the uplift of the mountain range.

The uplift of the range dates to the Laramide orogeny, about 70 to 50 million years ago, when compressive forces produced high-angle reverse faults on both north and south sides of the present mountain range. The east-west orientation of the Uintas is anomalous compared to most of the ranges of the Rocky Mountains; it may relate to changing stress patterns and rotation of the Colorado Plateau. [6] The Green River used to flow into the Mississippi River to the Gulf of Mexico, but changed to the Colorado River by going through the Uintas in ways not fully understood. [7]

The high Uintas were extensively glaciated during the last ice age, and most of the large stream valleys on both the north and south sides of the range held long valley glaciers. [8] However, despite reaching to over 13,500 feet (4,110 m) in elevation, the climate today is sufficiently dry that no glaciers survived even before the rapid current glacial retreat began in the middle nineteenth century. The Uintas are the most poleward mountain range in the world to reach over 13,000 feet (4,000 m) without modern glaciers, and are in fact the highest mountain range in the contiguous United States with no modern glaciers. Permafrost occurs at elevations above 10,000 feet (3,000 m) [9] and at times forms large rock glaciers.

In between the summits and ridgelines are wide, level basins, with some 500 small lakes. One of the most popular lakes is Mirror Lake because of its good fishing, scenic views, and easy road access.

Hydrology

Weber River Weber River.png
Weber River

The south and east sides of the range are largely within the Colorado River watershed, including the Blacks Fork and the Duchesne River, which are tributaries of the Green River. The Green is the major tributary of the Colorado River and flows in a tight arc around the eastern side of the range. (Indeed, John Wesley Powell said the Green was the "master stream" where it and the Colorado came together.)

The Bear and Weber rivers, the two largest tributaries of Great Salt Lake, are born on the west slope of the range. The Provo River, the largest tributary to Utah Lake, begins on the southern side of the range and flows west to Utah Lake, which itself drains via the Jordan River into Great Salt Lake.

Large portions of the mountain range receive over 40 inches (100 cm) of precipitation annually. [10] The high Uintas are snowcapped most of the year except for late July through early September. The Uinta Mountains have more than 400 miles (640 km) of streams and 1,000 lakes and ponds. [11]

Ecology

Gilbert Peak seen from lake 151 Gilbert Peak.jpg
Gilbert Peak seen from lake 151

The Uinta Mountains are part of the Wasatch and Uinta montane forests ecoregion. Nearly the entire range lies within Uinta-Wasatch-Cache National Forest (on the north and west) and Ashley National Forest (on the south and east). The highest peaks of the range are protected as part of the High Uintas Wilderness. The forests contain many species of trees, including lodgepole pine, subalpine fir, Engelmann spruce, Douglas-fir, and quaking aspen. There are also many species of grasses, shrubs, and forbs growing in the Uinta Mountains. Fauna are typical of central Rocky Mountains. Large grazing and browsing animals include Rocky Mountain Elk, Mule Deer, Moose, Pronghorn Antelope, mountain goats, and Rocky Mountain Bighorn Sheep. Mammalian predators include Black Bear, Mountain Lion, Coyotes, Red Fox, Badger, Wolverine, Marten, and Long-tailed Weasel. A Gray Wolf pack has been observed at the eastern end of the range, in Moffat County, Colorado. Raptors include Bald And Golden Eagles, Turkey Vulture, various hawks and harriers, and owls including Great Horned, Great Grey and Barn Owls. Other notable large birds include Sage Grouse and White-tailed Ptarmigan.

Points of interest

The Uintas is home to Camp Steiner, the highest Boy Scout camp in the United States at 10,400 feet (3,200 m). The camp is near mile marker 33 of the Mirror Lake Highway.

The Uinta Highline Trail traverses the entire range and is a popular backpacking trail.

Dinosaur National Monument is located on the southeast flank of the Uinta Mountains on the border between Colorado and Utah.

See also

Related Research Articles

Rocky Mountains Major mountain range in western North America

The Rocky Mountains, also known as the Rockies, are a major mountain range in western North America. The Rocky Mountains stretch 3,000 mi (4,800 km) in straight-line distance from the northernmost part of British Columbia, in western Canada, to New Mexico in the Southwestern United States. The northern terminus is located in the Liard River area east of the Pacific Coast Ranges, while the southernmost point is near the Albuquerque area adjacent the Rio Grande Basin and north of the Sandia–Manzano Mountain Range. Located within the North American Cordillera, the Rockies are distinct from the Cascade Range and the Sierra Nevada, which all lie farther to the west.

Laramide orogeny A period of mountain building in western North America, which started in the Late Cretaceous

The Laramide orogeny was a time period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. The exact duration and ages of beginning and end of the orogeny are in dispute. The Laramide orogeny occurred in a series of pulses, with quiescent phases intervening. The major feature that was created by this orogeny was deep-seated, thick-skinned deformation, with evidence of this orogeny found from Canada to northern Mexico, with the easternmost extent of the mountain-building represented by the Black Hills of South Dakota. The phenomenon is named for the Laramie Mountains of eastern Wyoming. The Laramide orogeny is sometimes confused with the Sevier orogeny, which partially overlapped in time and space.

Wasatch Range Mountain range in Utah, United States

The Wasatch Range is a mountain range in the western United States that runs about 160 miles (260 km) from the Utah-Idaho border south to central Utah. It is the western edge of the greater Rocky Mountains, and the eastern edge of the Great Basin region. The northern extension of the Wasatch Range, the Bear River Mountains, extends just into Idaho, constituting all of the Wasatch Range in that state.

Laramie Mountains

The Laramie Mountains are a range of moderately high peaks on the eastern edge of the Rocky Mountains in the U.S states of Wyoming and Colorado. The range is the northernmost extension of the line of the ranges along the eastern side of the Rockies, and in particular of the higher peaks of the Front Range directly to the south. North of the range, the gap between the Laramie range and the Bighorn Mountains provided the route for historical trails, such as the Oregon Trail, the Mormon Trail, and the Pony Express.

Green River Formation

The Green River Formation is an Eocene geologic formation that records the sedimentation in a group of intermountain lakes in three basins along the present-day Green River in Colorado, Wyoming, and Utah. The sediments are deposited in very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year. The sediments of the Green River Formation present a continuous record of six million years. The mean thickness of a varve here is 0.18 mm, with a minimum thickness of 0.014 mm and maximum of 9.8 mm.

Geology of the United States national geology

The richly textured landscape of the United States is a product of the dueling forces of plate tectonics, weathering and erosion. Over the 4.5 billion-year history of our Earth, tectonic upheavals and colliding plates have raised great mountain ranges while the forces of erosion and weathering worked to tear them down. Even after many millions of years, records of Earth's great upheavals remain imprinted as textural variations and surface patterns that define distinctive landscapes or provinces.

Geology of the Grand Canyon area Aspect of geology

The geology of the Grand Canyon area includes one of the most complete and studied sequences of rock on Earth. The nearly 40 major sedimentary rock layers exposed in the Grand Canyon and in the Grand Canyon National Park area range in age from about 200 million to nearly 2 billion years old. Most were deposited in warm, shallow seas and near ancient, long-gone sea shores in western North America. Both marine and terrestrial sediments are represented, including lithified sand dunes from an extinct desert. There are at least 14 known unconformities in the geologic record found in the Grand Canyon.

The exposed geology of the Bryce Canyon area in Utah shows a record of deposition that covers the last part of the Cretaceous Period and the first half of the Cenozoic era in that part of North America. The ancient depositional environment of the region around what is now Bryce Canyon National Park varied from the warm shallow sea in which the Dakota Sandstone and the Tropic Shale were deposited to the cool streams and lakes that contributed sediment to the colorful Claron Formation that dominates the park's amphitheaters.

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 of 336,700 km2 (130,000 mi2) within western Colorado, northwestern New Mexico, southern and eastern Utah, northern Arizona, and a tiny fraction in the extreme southeast of Nevada. 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.

Medicine Bow Mountains Mountain range in the Western United States

The Medicine Bow Mountains are a mountain range in the Rocky Mountains that extend for 100-mile (160 km) from northern Colorado into southern Wyoming. The northern extent of this range is the sub-range the Snowy Range. From the northern end of Colorado's Never Summer Mountains, the Medicine Bow mountains extend north from Cameron Pass along the border between Larimer and Jackson counties in Colorado and northward into south central Wyoming. In Wyoming, the range sits west of Laramie, in Albany and Carbon counties to the route of the Union Pacific Railroad and U.S. Interstate 80. The mountains often serve as a symbol for the city of Laramie. The range is home to Snowy Range Ski Area.

Sevier orogeny

The Sevier orogeny was a mountain-building event that affected western North America from northern Canada to the north to Mexico to the south.

North American Cordillera

The North American Cordillera is the North American portion of the American Cordillera which is a mountain chain (cordillera) along the western side of the Americas. The North American Cordillera covers an extensive area of mountain ranges, intermontane basins, and plateaus in western North America, including much of the territory west of the Great Plains. It is also sometimes called the Western Cordillera, the Western Cordillera of North America, or the Pacific Cordillera.

Brazos Mountains Mountain range in New Mexico

The Brazos Mountains is a range in far northern Rio Arriba County, in northern New Mexico in the southwestern United States. The range is part of the Tusas Mountains – the southern portion of the San Juan Mountains which are more well known in Colorado. A high crest runs from the border with Colorado for over 20 miles (32 km) in a south-southeasterly direction. The high point of the range at 11,405 feet (3,476 m) is on Grouse Mesa, at the Brazos Benchmark. Two miles (3 km) to the southeast is the more distinctive Brazos Peak, at 11,288 feet.

Uinta Basin

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

Duchesne River

The Duchesne River, located in the Uintah Basin region of Utah in the western United States, is a tributary of the Green River. The watershed of the river covers the Northeastern corner of Utah. The Duchesne River is 115 miles (185 km) long, and drains a total land area of 3,790 square miles (9,800 km2).

The geology of Wyoming includes some of the oldest Archean rocks in North America, overlain by thick marine and terrestrial sediments formed during the Paleozoic, Mesozoic and Cenozoic, including oil, gas and coal deposits. Throughout its geologic history, Wyoming has been uplifted several times during the formation of the Rocky Mountains, which produced complicated faulting that traps hydrocarbons.

The geology of Utah includes rocks formed at the edge of the proto-North American continent during the Precambrian. A shallow marine sedimentary environment covered the region for much of the Paleozoic and Mesozoic, followed by dryland conditions, volcanism and the formation of the basin and range terrain in the Cenozoic. Utah is a state in the western United States.

The geology of Colorado was assembled from island arcs accreted onto the edge of the ancient Wyoming Craton. The Sonoma orogeny uplifted the ancestral Rocky Mountains in parallel with the diversification of multicellular life. Shallow seas covered the regions, followed by the uplift current Rocky Mountains and intense volcanic activity. Colorado has thick sedimentary sequences with oil, gas and coal deposits, as well as base metals and other minerals.

Greater Green River Basin

The Greater Green River Basin (GGRB) is a 21,000 square mile basin located in Southwestern Wyoming. The Basin was formed during the Cretaceous period sourced by underlying Permian and Cretaceous deposits. The GGRB is host to many anticlines created during the Laramide Orogeny trapping many of its hydrocarbon resources. It is bounded by the Rawlins Uplift, Uinta Mountains, Sevier overthrust belt, Sieria Madre Mountains, and the Wind River Mountain Range. The Greater Green River Basin is subdivided into four smaller basins the Green River Basin, Great Divide Basin, Washakie Basin, and Sand Wash Basin. Each of which possesses hydrocarbons that have been economically exploited. There are 303 named fields throughout the basin the majority of which produce natural gas, the largest of these gas fields is the Jonah Field.

California River is the name of a northeastward flowing river system that existed in the Cretaceous-Eocene in the western United States. It is so named because it flowed from the Mojave region of California to the Uinta Basin of Utah, transporting sediments along this track towards Lake Uinta.

References

  1. "Kings Peak, Utah". Peakbagger.com. Retrieved 2008-02-23.
  2. Paleomagnetic results from the Neoproterozoic Uinta Mountain Group
  3. John McPhee, Basin and Range, New York: Farrar, Straus, and Giroux, 1981, pp.198-199.
  4. Nelson, S. T.; Keith, J. D.; Constenius, K. N.; Olcott, J.; Duerichen, E.; Tingey, D. G. (1 May 2008). "Genesis of fibrous calcite and emerald by amagmatic processes in the southwestern Uinta Mountains, Utah". Rocky Mountain Geology. 43 (1): 1–21. doi:10.2113/gsrocky.43.1.1.
  5. Condie, Kent C.; Dennis Lee; G. Lang Farmer (2001). "Tectonic setting and provenance of the Neoproterozoic Uinta Mountain and Big Cottonwood groups, northern Utah: constraints from geochemistry, Nd isotopes, and destrital modes". Sedimentary Geology . 141–142: 443–464. doi:10.1016/s0037-0738(01)00086-0.
  6. Hamilton, W.B., 1981, Plate-tectonic mechanism of Laramide deformation, in Boyd, D.W., and Lillegraven, J.A., eds., Rocky Mountain foreland basement tectonics: University of Wyoming Contributions to Geology, v. 19, p. 87–92.
  7. Davis, Jim. "Glad You Asked: Why Does A River Run Through It?". Utah Geological Survey. Archived from the original on 2019-02-09.
  8. Utah Geological Survey. "Are there glaciers in Utah's mountains?" . Retrieved 2008-04-11.
  9. Glacial Geology of the Northern Uinta Mountains
  10. WRCC.dri.edu
  11. Probst, Jeffrey, and Probst, Brad, Hiking Utah's High Uintas, pg. 3, Morris Book Publishing, LLC, 2006 ISBN   0-7627-3911-8

Further reading