Dinosaur National Monument is an American national monument located on the southeast flank of the

Uinta Mountains The Uinta Mountains ( ) 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 c ...

on the border between

Colorado Colorado (, other variants) is a state in the Mountain West subregion of the Western United States. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of t ...

and

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

at the confluence of the

Green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...

and

Yampa Yampa is a Colorado municipalities#Statutory town, statutory town in Routt County, Colorado, Routt County, Colorado, United States. The population was 429 at the United States Census, 2010, 2010 census. City name is the Ute dialect, Northern U ...

rivers. Although most of the monument area is in

Moffat County, Colorado Moffat County is a county located in the U.S. state of Colorado. As of the 2020 census, the population was 13,292. The county seat is Craig. With an area of 4,751 square miles, it is the 2nd largest county by area in Colorado, behind Las An ...

, the Dinosaur Quarry is located in Utah, north of the town of

Jensen, Utah Jensen is a census-designated place in eastern Uintah County, Utah, United States. The population was 412 at the 2010 census. It lies along the Green River and U.S. Route 40, southeast of the city of Vernal, the county seat of Uintah County, an ...

. The nearest Colorado town is

Dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

while the nearest city is

Vernal, Utah Vernal, the county seat and largest city in Uintah County is in northeastern Utah, approximately east of Salt Lake City and west of the Colorado border. As of the 2010 census, the city population was 9,089. The population has since grown to ...

. Originally preserved in 1915 to protect its famous Dinosaur Quarry, the monument was greatly expanded in 1938 to include its wealth of natural history. The park's wild landscapes, topography, geology, paleontology, and history make it a unique resource for both science and recreation. The park contains over 800 paleontological sites and has fossils of

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

s including ''

Allosaurus ''Allosaurus'' () is a genus of large carnosaurian theropod dinosaur that lived 155 to 145 million years ago during the Late Jurassic epoch ( Kimmeridgian to late Tithonian). The name "''Allosaurus''" means "different lizard" alludin ...

'', ''

Deinonychus ''Deinonychus'' ( ; ) is a genus of dromaeosaurid theropod dinosaur with one described species, ''Deinonychus antirrhopus''. This species, which could grow up to long, lived during the early Cretaceous Period, about 115–108 million ye ...

'', '' Abydosaurus'', and various

sauropods Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their b ...

. The ''Abydosaurus'' consists of a nearly complete skull, the lower jaw, and first four neck vertebrae. The specimen was found at the base of the Mussentuchit Member of the

Cedar Mountain Formation The Cedar Mountain Formation is the name given to a distinctive sedimentary geologic formation in eastern Utah, spanning most of the early and mid-Cretaceous. The formation was named for Cedar Mountain (Utah), Cedar Mountain in northern Emery Coun ...

and is the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

for the description. Paleontologist Earl Douglass of the Carnegie Museum discovered eight vertebra of an Apatosaurus on August 17, 1909, which became the first dinosaur skeleton discovered and excavated at the new Carnegie Quarry. The area around the quarry was declared a national monument on October 4, 1915. The

International Dark-Sky Association The International Dark-Sky Association (IDA) is a United States-based non-profit organization incorporated in 1988 by founders David Crawford, a professional astronomer, and Tim Hunter, a physician/amateur astronomer. The mission of the IDA is " ...

designated Dinosaur National Monument an International Dark Sky Park in April 2019.

Geology

The rock layer enclosing the fossils is a

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

and conglomerate bed of

alluvial Alluvium (from Latin ''alluvius'', from ''alluere'' 'to wash against') is loose clay, silt, sand, or gravel that has been deposited by running water in a stream bed, on a floodplain, in an alluvial fan or beach, or in similar settings. Alluv ...

or river bed origin known as the

Morrison Formation The Morrison Formation is a distinctive sequence of Late Jurassic, Upper Jurassic sedimentary rock found in the western United States which has been the most fertile source of dinosaur fossils in North America. It is composed of mudstone, sandsto ...

from the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

Period some 150 million years old. The dinosaurs and other ancient animals were carried by the river system which eventually entombed their remains in Utah. The pile of sediments were later buried and lithified into solid rock. The layers of rock were later uplifted and tilted to their present angle by the mountain building forces that formed the

during the

Laramide orogeny 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 o ...

. The relentless forces of

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

exposed the layers at the surface to be found by paleontologists.

History

Fremont people

Matriarch - Petroglyphs in Dinosaur National Monument

The Fremont people lived in the area of what is now Dinosaur National Monument before the 14th century, with archaeological evidence dating from 200 to 1300.

Archaeologists Archaeology or archeology is the scientific study of human activity through the recovery and analysis of material culture. The archaeological record consists of artifacts, architecture, biofacts or ecofacts, sites, and cultural landscap ...

first studied and named the Fremont culture along the

Fremont River The Fremont River is a long river in southeastern Utah, United States that flows from the Johnson Valley Reservoir, which is located on the Wasatch Plateau near Fish Lake, southeast through Capitol Reef National Park to the Muddy Creek near Ha ...

in south-central Utah and have since traced it through much of the Green and Colorado River drainages. The Fremont did not build large permanent dwellings; instead, they lived in small bands within natural shelters, such as rock overhangs or shallow caves, or small villages. They consumed plant foods, such as

pine nut Pine nuts, also called piñón (), pinoli (), pignoli or chilgoza (), are the edible seeds of pines (family Pinaceae, genus ''Pinus''). According to the Food and Agriculture Organization, only 29 species provide edible nuts, while 20 are trade ...

s, berries, and

cactus A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...

fruits, as well as wild game, including

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whit ...

bighorn sheep The bighorn sheep (''Ovis canadensis'') is a species of sheep native to North America. It is named for its large horns. A pair of horns might weigh up to ; the sheep typically weigh up to . Recent genetic testing indicates three distinct subspec ...

, smaller mammals, and birds. They also grew corn, beans, and squash, sometimes using irrigation techniques. The fate of the Fremont culture is unclear. Recent theories suggest that the Fremont’s lifestyle may have changed due to drought or other climate factors, dwindling natural resources, or the influence of other neighboring cultures. They left evidence of their presence in the form of

petroglyph A petroglyph is an image created by removing part of a rock surface by incising, picking, carving, or abrading, as a form of rock art. Outside North America, scholars often use terms such as "carving", "engraving", or other descriptions ...

s and

pictographs A pictogram, also called a pictogramme, pictograph, or simply picto, and in computer usage an icon, is a graphic symbol that conveys its meaning through its pictorial resemblance to a physical object. Pictographs are often used in writing and gr ...

of human and animal figures, and abstract designs. Human figures typically have

trapezoid A quadrilateral with at least one pair of parallel sides is called a trapezoid () in American and Canadian English. In British and other forms of English, it is called a trapezium (). A trapezoid is necessarily a Convex polygon, convex quadri ...

al bodies and elaborate decorations that suggest

headdresses Headgear, headwear, or headdress is the name given to any element of clothing which is worn on one's head, including hats, helmets, turbans and many other types. Headgear is worn for many purposes, including protection against the elements, d ...

, earrings, necklaces, or shields. The animal figures include bighorn sheep, birds, snakes, and lizards. Purely abstract or geometric designs, such as circles, spirals, and various combinations of lines, are common. Many designs in the monument are accessible for close viewing, along four trails in Utah, one of which is near the visitor center, and a fifth trail in Colorado.

Early scientific explorations

The dinosaur fossil beds (

bone bed A bone bed is any geological stratum or deposit that contains bones of whatever kind. Inevitably, such deposits are sedimentary in nature. Not a formal term, it tends to be used more to describe especially dense collections such as Lagerstätte. ...

s) were discovered in 1909 by Earl Douglass, a

paleontologist Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...

working and collecting for the

Carnegie Museum of Natural History The Carnegie Museum of Natural History (abbreviated as CMNH) is a natural history museum in the Oakland neighborhood of Pittsburgh, Pennsylvania. It was founded by Pittsburgh-based industrialist Andrew Carnegie in 1896. Housing some 22 million ...

. He and his crews excavated thousands of

fossils A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in ...

and shipped them back to the museum in

Pittsburgh, Pennsylvania Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...

for study and display.

National monument

President

Woodrow Wilson Thomas Woodrow Wilson (December 28, 1856February 3, 1924) was an American politician and academic who served as the 28th president of the United States from 1913 to 1921. A member of the Democratic Party, Wilson served as the president of ...

proclaimed the dinosaur beds as Dinosaur National Monument in 1915. The monument boundaries were expanded in 1938 from the original surrounding the dinosaur quarry in Utah, to in Utah and Colorado, encompassing the river canyons of the

and

Echo Park Dam controversy

Confluence of the Green and Yampa Rivers (17396238518)

The plans made by the U.S. Bureau of Reclamation on a ten-dam, billion dollar

Colorado River Storage Project The Colorado River Storage Project is a United States Bureau of Reclamation project designed to oversee the development of the upper Colorado River basin. The project provides hydroelectric power, flood control and water storage for participat ...

began to arouse opposition in the early 1950s when it was announced that one of the proposed dams would be at

Echo Park Echo Park is a neighborhood in the east-central region of Los Angeles, California. Located to the northwest of Downtown, it is bordered by Silver Lake to the west and Chinatown to the east. The culturally diverse neighborhood has become known f ...

, in the middle of Dinosaur National Monument. The controversy assumed major proportions, dominating conservation politics for years.

David Brower David Ross Brower (; July 1, 1912 – November 5, 2000) was a prominent environmentalist and the founder of many environmental organizations, including the John Muir Institute for Environmental Studies (1997), Friends of the Earth (1969), Eart ...

, executive director of the

Sierra Club The Sierra Club is an environmental organization with chapters in all 50 United States, Washington D.C., and Puerto Rico. The club was founded on May 28, 1892, in San Francisco, California, by Scottish-American preservationist John Muir, who be ...

, and

Howard Zahniser Howard Clinton Zahniser (February 25, 1906 – May 5, 1964) was an American environmental activist. For nearly 20 years, he helped lead The Wilderness Society as executive secretary, executive director, and editor of ''The Living Wilderness'', fr ...

of The Wilderness Society led an unprecedented nationwide campaign to preserve the free-flowing rivers and scenic canyons of the Green and Yampa Rivers. They argued that if a national monument was not safe from development, how could any wildland be kept intact? On the other side of the argument were powerful members of

Congress A congress is a formal meeting of the representatives of different countries, constituent states, organizations, trade unions, political parties, or other groups. The term originated in Late Middle English to denote an encounter (meeting of a ...

from western states, who were committed to the project in order to secure water rights, obtain cheap

hydroelectric power Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

and develop

reservoirs A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including control ...

as tourist destinations. After much debate, Congress settled on a compromise that eliminated

Echo Park Dam Echo Park Dam was proposed in the 1950s by the U.S. Bureau of Reclamation as a central feature of the Colorado River Storage Project. Situated on the Green River, a major tributary of the Colorado River, the dam was proposed for the Echo Park distr ...

and authorized the rest of the project. The Colorado River Storage Project Act became law on April 11, 1956. It stated, "that no dam or reservoir constructed under the authorization of the Act shall be within any National Park or Monument."

Historic places

Places on the list of National Register of Historic Places include: : Prehistoric sites :* Castle Park Archeological District, a prehistoric residential site with inhabition during 1500 - 1000 BC and again from AD 1000 - 1899 by the Prehistoric Fremont culture,

Ute Ute or UTE may refer to: * Ute (band), an Australian jazz group * Ute (given name) * ''Ute'' (sponge), a sponge genus * Ute (vehicle), an Australian and New Zealand term for certain utility vehicles * Ute, Iowa, a city in Monona County along ...

and

Shoshone people The Shoshone or Shoshoni ( or ) are a Tribe (Native American), Native American tribe with four large cultural/linguistic divisions: * Eastern Shoshone: Wyoming * Northern Shoshone: southern Idaho * Western Shoshone: Nevada, northern Utah * Goshu ...

. :* Mantle's Cave is a prehistoric Fremont culture residential site from 499 BC - AD 1749. :Other sites :*

Josie Bassett Morris Ranch Complex The Josie Bassett Morris Ranch Complex comprises a small complex of buildings in what is now Dinosaur National Monument in northeastern Uintah County, Utah, United States. The complex is listed as a historic district on the National Register of ...

:* Denis Julien Inscription :* Rial Chew Ranch Complex :* Upper Wade and Curtis Cabin Harpers Corner view east

Climate

The Dinosaur National Monument sits on a vast area of desert land in Northwestern Colorado and Northeastern Utah. Typical of high deserts, summer temperatures can be exceedingly hot, while winter temperatures can be very cold. Snowfall is common, but the snow melts rapidly in the arid and sunny climates of these states. Rainfall is very low, and the evaporation rate classifies the area as desert, even though the rainfall exceeds 10 inches.

Features

The quarry

Dinosaur National Monument Quarry Exhibit Hall

The "Wall of Bones" located within the Dinosaur Quarry building in the park consists of a steeply tilted (67° from horizontal)

rock Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

layer Layer or layered may refer to: Arts, entertainment, and media * ''Layers'' (Kungs album) * ''Layers'' (Les McCann album) * ''Layers'' (Royce da 5'9" album) *"Layers", the title track of Royce da 5'9"'s sixth studio album * Layer, a female Maveri ...

which contains thousands of

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

s. The preserved section is only a portion of what was originally present when Douglass made his discovery as seen on the map above. When work ceased in 1922, a portion of the quarry was left for future development. This work began as part of President Franklin Roosevelt's Civil Works Administration, which provided employment during the Depression under the Transient Relief Service and later under the Works Progress Administration. This work included constructing a road to the quarry, removal of overburden covering the bone-bearing strata, and building of a small, temporary museum. The War interrupted work but this was resumed in 1951 with the building of a small metal building over the east portion of the quarry to test whether bone was abundant enough to warrant a larger, more permanent building. This more permanent building was erected in the mid-1950s as part of the National Park Service Mission 66 plan. The architectural design was high controversial for its ultra-modern use of glass, steel and concrete ramp that spiraled around a cylindrical office tower. The building opened at the dedication ceremony on June 1, 1958. The design had two levels and abundant natural light so that visitors could watch technicians remove the hard rock to reveal the fossil bones in-situ. In July 2006, the Quarry Visitor Center was closed due to structural problems that since 1958 had plagued the building because it was built on unstable clay. The decision was made to build a new facility elsewhere in the monument to house the visitor center and administrative functions, making it easier to resolve the structural problems of the quarry building while still retaining a portion of the historic

Mission 66 Mission 66 was a United States National Park Service ten-year program that was intended to dramatically expand Park Service visitor services by 1966, in time for the 50th anniversary of the establishment of the Park Service. When the National P ...

era exhibit hall. It was announced in April 2009 that Dinosaur National Monument would receive $13.1 million to refurbish and reopen the gallery as part of the Obama administration's $750 billion stimulus plan. The Park Service successfully rebuilt the Quarry Exhibit Hall, supporting its weight on 70-foot steel micropile columns that extend to the bedrock below the unstable clay. The Dinosaur Quarry was reopened in Fall 2011.

Fossils from Carnegie Quarry

Dinosaur National Monument-inside the Dinosaur Quarry building

:Now enclosed by the Dinosaur Quarry building (Gilmore (1936), Foster (2003); Good (2004). ;Planta :Coniferophyta ;Mollusca :''Unio'' sp. :''Vetulonia'' sp. ;Reptilia :Testudines ::Amphichelydia :::''

Glyptops ''Glyptops'' (Greek for "grooved face") is an extinct genus of pleurosternid freshwater turtle known from the Late Jurassic of North America. Taxonomy The type species, ''Glyptops plicatulus'', was first described as ''Compsemys plicatulus'' by ...

plicatus'' :::''

Dinochelys ''Dinochelys'' (from Greek ''deinos'' -terrible- and ''chelys'' -turtle) is an extinct genus of paracryptodiran turtle from the Late Jurassic Morrison Formation. See also * Paleobiota of the Morrison Formation The Morrison Formation is a di ...

whitei'' :Rhynchocephalia :::''

Opisthias ''Opisthias'' is a genus of sphenodont reptile. The type species, ''Opisthias rarus'', is known from the Late Jurassic (Kimmeridgian-Tithonian) Morrison Formation of western North America, present in stratigraphic zones 2 and 4–6. Distributi ...

rarus'' :Crocodilia ::Mesosuchia :::Gonipholididae ::::''

Goniopholis ''Goniopholis'' (meaning "angled scale") is an extinct genus of goniopholidid crocodyliform that lived in Europe and Africa during the Late Jurassic and Early Cretaceous. Being semi-aquatic it is very similar to modern crocodiles. It ranged from ...

'' sp. :::Atoposauridae ::::'' Hoplosuchus kayi'' (h) ;Dinosauria :Saurischia ::Theropoda :::''

Ceratosaurus ''Ceratosaurus'' (from Greek κέρας/κέρατος, ' meaning "horn" and σαῦρος ' meaning "lizard") was a carnivorous theropod dinosaur in the Late Jurassic period ( Kimmeridgian to Tithonian). The genus was first described in 1 ...

'' sp. :::''

Torvosaurus ''Torvosaurus'' () is a genus of carnivorous megalosaurid theropod dinosaur that lived approximately 165 to 148 million years ago during the late Middle and Late Jurassic period (Callovian to Tithonian stages) in what is now Colorado, Portuga ...

'' sp. :::''

fragilis'' ::Sauropoda :::''

Apatosaurus ''Apatosaurus'' (; meaning "deceptive lizard") is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, ''A. ajax'', in 1877, an ...

louisae'' (h) :::''

Barosaurus ''Barosaurus'' ( ) was a giant, long-tailed, long-necked, plant-eating sauropod dinosaur closely related to the more familiar ''Diplodocus''. Remains have been found in the Morrison Formation from the Upper Jurassic Period of Utah and South Da ...

lentus'' :::'' Camarasaurus lentus'' :::''

Diplodocus ''Diplodocus'' (, , or ) was a genus of diplodocid sauropod dinosaurs, whose fossils were first discovered in 1877 by S. W. Williston. The generic name, coined by Othniel Charles Marsh in 1878, is a neo-Latin term derived from Greek δι� ...

hallorum'' :::''

Uintasaurus ''Camarasaurus'' ( ) was a genus of quadrupedal, herbivorous dinosaurs and is the most common North American sauropod fossil. Its fossil remains have been found in the Morrison Formation, dating to the Late Jurassic epoch (Kimmeridgian to Titho ...

douglassi'' (h) (now ''Camarasaurus lentus'') :Ornithischia ::Stegosauria :::''

Stegosaurus ''Stegosaurus'' (; ) is a genus of herbivorous, four-legged, armored dinosaur from the Late Jurassic, characterized by the distinctive kite-shaped upright plates along their backs and spikes on their tails. Fossils of the genus have been foun ...

'' ungulatus ::Ornithopoda :::Iguanodontia ::::''

Camptosaurus ''Camptosaurus'' ( ) is a genus of plant-eating, beaked ornithischian dinosaurs of the Late Jurassic period of western North America and possibly also Europe. The name means 'flexible lizard' ( Greek (') meaning 'bent' and (') meaning 'li ...

aphanoecetes'' (h) :::Dryosauridae ::::''

Dryosaurus ''Dryosaurus'' ( , meaning 'tree lizard', Greek ' () meaning 'tree, oak' and () meaning 'lizard'; the name reflects the forested habitat, not a vague oak-leaf shape of its cheek teeth as is sometimes assumed) is a genus of an ornithopod dinosaur ...

elderae'' (h) :(h) = holotype

References

External links

* * * {{authority control National Park Service National Monuments in Colorado National Park Service National Monuments in Utah Fossil parks in the United States Dinosaur museums in the United States Natural history museums in Utah Museums in Uintah County, Utah Features of the Uinta Mountains Green River (Colorado River tributary) Protected areas of Moffat County, Colorado Protected areas of Uintah County, Utah Paleontological protected areas in the United States Paleontology in Colorado Paleontology in Utah Morrison Formation Jurassic Colorado Jurassic geology of Utah Jurassic paleontological sites of North America Environmental controversies Sierra Club Protected areas established in 1915 1915 establishments in Colorado 1915 establishments in Utah 1915 establishments in the United States Badlands of the United States