Dinosaur National Monument

Last updated
Dinosaur National Monument entrance Dinosaur National Monument sign.jpg
Dinosaur National Monument entrance
Dinosaur National Monument
IUCN category V (protected landscape/seascape) [1]
Dinosaur National Monument Camarasaurus.jpg
A dinosaur skull embedded in rock at Dinosaur National Monument
Usa edcp location map.svg
Red pog.svg
Location in the United States
Location Moffat County, Colorado and Uintah County, Utah, U.S.
Nearest city Vernal, Utah
Coordinates 40°32′N108°59′W / 40.533°N 108.983°W / 40.533; -108.983 Coordinates: 40°32′N108°59′W / 40.533°N 108.983°W / 40.533; -108.983
Area210,844 acres (853.26 km2)
EstablishedOctober 4, 1915 [2]
Visitors304,468(in 2018) [3]
Governing bodyU.S. National Park Service
Website Dinosaur National Monument
Map showing the boundaries of Dinosaur National Monument NPS dinosaur-national-monument-map.jpg
Map showing the boundaries of Dinosaur National Monument

Dinosaur National Monument is an American national monument located on the southeast flank of the Uinta Mountains [4] on the border between Colorado and Utah at the confluence of the Green and Yampa rivers. Although most of the monument area is in Moffat County, Colorado, the Dinosaur Quarry is located in Utah, north of the town of Jensen, Utah at 40°26′29″N109°18′04″W / 40.44139°N 109.30111°W / 40.44139; -109.30111 . The nearest Colorado town is Dinosaur while the nearest city is Vernal, Utah.


Originally preserved in 1915 to protect its famous Dinosaur Quarry, [5] 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 dinosaurs including Allosaurus , Deinonychus , Abydosaurus , and various sauropods. [5] 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 and is the holotype for the description.

Paleontologist Earl Douglass of the Carnegie Museum discovered eight vertebra of an Apatosaurus on August 17, 1909, [2] 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. [2] The International Dark-Sky Association designated Dinosaur National Monument an International Dark Sky Park in April 2019. [6]


Multicolored beds of the Brushy Basin Member of the Morrison Formation DNM Morrison.jpg
Multicolored beds of the Brushy Basin Member of the Morrison Formation
The Quarry Visitor Center in context to the landscape. View is from the west. DNM strata.jpg
The Quarry Visitor Center in context to the landscape. View is from the west.

The rock layer enclosing the fossils is a sandstone and conglomerate bed of alluvial or river bed origin known as the Morrison Formation from the Jurassic 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 Uinta Mountains [4] during the Laramide orogeny. [5] The relentless forces of erosion exposed the layers at the surface to be found by paleontologists.


Fremont people

Petroglyphs at McKee Spring in Dinosaur National Monument Matriarch - Petroglyphs in Dinosaur National Monument.jpg
Petroglyphs at McKee Spring 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 c. 200 to c. 1300. Archaeologists first studied and named the Fremont culture along the Fremont River in south-central Utah and have since traced it through much of the Green and Colorado River drainages. [8]

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 nuts, berries, and cactus fruits, as well as wild game, including mule deer, bighorn sheep, smaller mammals, and birds. They also grew corn, beans, and squash, sometimes using irrigation techniques. [8]

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. [8] They left evidence of their presence in the form of petroglyphs and pictographs of human and animal figures, and abstract designs. Human figures typically have trapezoidal bodies and elaborate decorations that suggest headdresses, 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. [9]

Early scientific explorations

Paleontologist chips rock matrix from a column of vertebrae in the Dinosaur Quarry. Dino vertebrae.jpg
Paleontologist chips rock matrix from a column of vertebrae in the Dinosaur Quarry.

The dinosaur fossil beds (bone beds) were discovered in 1909 by Earl Douglass, a paleontologist working and collecting for the Carnegie Museum of Natural History. [10] He and his crews excavated thousands of fossils and shipped them back to the museum in Pittsburgh, Pennsylvania for study and display.

National monument

President Woodrow Wilson proclaimed the dinosaur beds as Dinosaur National Monument in 1915. The monument boundaries were expanded in 1938 from the original 80 acres (0.13 sq mi; 0.32 km2) surrounding the dinosaur quarry in Utah, to 210,844 acres (329 sq mi; 853 km2) in Utah and Colorado, encompassing the river canyons of the Green and Yampa. [2]

Echo Park Dam controversy

Confluence of the Green and Yampa Rivers Confluence of the Green and Yampa Rivers (17396238518).jpg
Confluence of the Green and Yampa Rivers

The plans made by the U.S. Bureau of Reclamation on a ten-dam, billion dollar Colorado River Storage Project began to arouse opposition in the early 1950s when it was announced that one of the proposed dams would be at Echo Park, in the middle of Dinosaur National Monument. The controversy assumed major proportions, dominating conservation politics for years. David Brower, executive director of the Sierra Club, and Howard Zahniser 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? [11]

On the other side of the argument were powerful members of Congress from western states, who were committed to the project in order to secure water rights, obtain cheap hydroelectric power and develop reservoirs as tourist destinations. After much debate, Congress settled on a compromise that eliminated Echo Park Dam 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." [12]

Historians view the Echo Park Dam controversy as signaling the start of an era that includes major conservationist political successes such as the Wilderness Act and the Wild and Scenic Rivers Act.[ citation needed ]

Historic places

Places on the list of National Register of Historic Places include: [13]

Prehistoric sites
Other sites
Green River Canyon in Dinosaur National Monument viewed west from Harper's Corner DinosaurNM1Panorama.jpg
Green River Canyon in Dinosaur National Monument viewed west from Harper's Corner
View east from Harpers Corner showing the local geology Harpers Corner view east.jpg
View east from Harpers Corner showing the local geology


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.

Climate data for Dinosaur National Monument
Average high °F (°C)33.0
Average low °F (°C)10.8
Average precipitation inches (mm)0.64
Average snowfall inches (cm)9.2
Source: The Western Regional Climate Center [15]


The quarry

The Quarry Exhibit Hall Dinosaur National Monument Quarry Exhibit Hall.jpg
The Quarry Exhibit Hall
Dinosaur bones on the quarry wall viewed east. This shows the bones lay three-dimensionally in the sandstone. Bones on Quarry.jpg
Dinosaur bones on the quarry wall viewed east. This shows the bones lay three-dimensionally in the sandstone.
Revised quarry map combining the original Douglass map, later historical data and current bones. DNM Quarry map.jpg
Revised quarry map combining the original Douglass map, later historical data and current bones.
The Green River in Dinosaur National Monument. Green River in DNM.jpg
The Green River in Dinosaur National Monument.

The "Wall of Bones" located within the Dinosaur Quarry building in the park consists of a steeply tilted (67° from horizontal) rock layer which contains thousands of dinosaur fossils. 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. [16] 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. [17] 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 era exhibit hall. [18] 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. [19] 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. [20] The Dinosaur Quarry was reopened in Fall 2011.

Fossils from Carnegie Quarry

Workers inside the Dinosaur Quarry building Dinosaur National Monument-inside the Dinosaur Quarry building.jpeg
Workers inside the Dinosaur Quarry building
Now enclosed by the Dinosaur Quarry building (Gilmore (1936), Foster (2003); Good (2004).
Unio sp.
Vetulonia sp.
Glyptops plicatus
Dinochelys whitei
Opisthias rarus
Goniopholis sp.
Hoplosuchus kayi (h)
Ceratosaurus sp.
Torvosaurus sp.
Allosaurus fragilis
Apatosaurus louisae (h)
Barosaurus lentus
Camarasaurus lentus
Diplodocus longus
Uintasaurus douglassi (h) (now Camarasaurus lentus)
Stegosaurus ungulatus
Camptosaurus aphanoecetes (h)
Dryosaurus elderae (h)
(h) = holotype

See also

Related Research Articles

Green River (Colorado River tributary)

The Green River, located in the western United States, is the chief tributary of the Colorado River. The watershed of the river, known as the Green River Basin, covers parts of Wyoming, Utah, and Colorado. The Green River is 730 miles (1,170 km) long, beginning in the Wind River Mountains of Wyoming and flowing through Wyoming and Utah for most of its course, except for 40 miles (64 km) into western Colorado. Much of the route is through the Colorado Plateau and through some of the most spectacular canyons in the United States. It is only slightly smaller than the Colorado when the two rivers merge, but typically carries a larger load of silt. The average yearly mean flow of the river at Green River, Utah is 6,121 cubic feet (173.3 m3) per second.

Yampa River river in northwestern Colorado, United States

The Yampa River flows 250 miles (400 km) through northwestern Colorado in the United States. Rising in the Rocky Mountains, it is a tributary of the Green River and a major part of the Colorado River system. The Yampa is one of the few free-flowing rivers in the western United States, with only a few small dams and diversions.

<i>Camarasaurus</i> Camarasaurid sauropod dinosaur genus from Late Jurassic Period

Camarasaurus was a genus of quadrupedal, herbivorous dinosaurs. It was the most common of the giant sauropods to be found in North America. Its fossil remains have been found in the Morrison Formation of Colorado and Utah, dating to the Late Jurassic epoch, between 155 and 145 million years ago.

Fossil Butte National Monument

Fossil Butte National Monument is a United States National Monument managed by the National Park Service, located 15 miles (24 km) west of Kemmerer, Wyoming, United States. It centers on an assemblage of Eocene Epoch animal and plant fossils associated with Fossil Lake—the smallest lake of the three great lakes which were then present in what are now Wyoming, Utah, and Colorado. The other two lakes were Lake Gosiute and Lake Uinta. Fossil Butte National Monument was established as a national monument on October 23, 1972.

<i>Barosaurus</i> Diplodocid sauropod dinosaur genus from Upper Jurrasic Period

Barosaurus was a giant, long-tailed, long-necked, plant-eating 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 Dakota. It is present in stratigraphic zones 2–5.

<i>Dryosaurus</i> Extinct genus of reptiles

Dryosaurus is a genus of an ornithopod dinosaur that lived in the Late Jurassic period. It was an iguanodont. Fossils have been found in the western United States and were first discovered in the late 19th century. Valdosaurus canaliculatus and Dysalotosaurus lettowvorbecki were both formerly considered to represent species of Dryosaurus.

Gates of Lodore Canyon entrance in Colorado

The Gates of Lodore is the scenic entrance to the Canyon of Lodore, a canyon on the Green River in northwestern Colorado, United States. The name Gates of Lodore has become synonymous with the canyon itself and the two names are used interchangeably. The Canyon commences as the Green River departs Browns Park and cuts through the Uinta Mountains meandering eighteen miles until its end at Echo Park (Colorado), the confluence of the Green and Yampa River. It was named by the Powell Expedition after the English poem Cataract of Lodore. It is located in Dinosaur National Monument.

<i>Brontosaurus</i> Diplodocid sauropod dinosaur genus from Late Jurassic Period

Brontosaurus is a genus of gigantic quadruped sauropod dinosaurs. Although the type species, B. excelsus, had long been considered a species of the closely related Apatosaurus, researchers proposed in 2015 that Brontosaurus is a genus separate from Apatosaurus and that it contains three species: B. excelsus, B. yahnahpin, and B. parvus.

Echo Park (Colorado)

Echo Park (Colorado) is a remote river bottom surrounded by canyon walls on the Green River, just downstream from the confluence with the Yampa River and across the stream from the dramatic southern end of Steamboat Rock in Dinosaur National Monument. It was first mapped and given its name by the Powell Geographic Expedition in 1869. A proposed dam at Echo Park turned into a nationwide environmental controversy in the early 1950s. The Sierra Club and other conservationist groups helped forge a compromise in Congress that eliminated the Echo Park Dam from the Colorado River Storage Project Act of 1956.

Charles W. Gilmore

Charles Whitney Gilmore was an American paleontologist who gained renown in the early 20th century for his work on vertebrate fossils during his career at the United States National Museum. Gilmore named many dinosaurs in North America and Mongolia, including the Cretaceous sauropod Alamosaurus, Alectrosaurus, Archaeornithomimus, Bactrosaurus, Brachyceratops, Chirostenotes, Mongolosaurus, Parrosaurus, Pinacosaurus, Styracosaurus ovatus and Thescelosaurus.

Dinosaur Diamond Prehistoric Highway

The Dinosaur Diamond Prehistoric Highway is a 512-mile-long (824 km) National Scenic Byway in the U.S. states of Utah and Colorado. The highway forms a diamond-shaped loop with vertices at Moab, Helper, Vernal and Grand Junction.

Quarry Visitor Center United States historic place

Quarry Visitor Center, in Dinosaur National Monument in Utah was built as part of the National Park Service's Mission 66 program of modern architectural design in the US national parks. This visitor center exemplifies the philosophy of locating visitor facilities immediately at the resource being interpreted. The visitor center was closed from 2006 to 2011 due to structural damage from unstable soils. The rotunda structure was demolished and replaced with a new structure of different design, while the quarry section was being stabilized and repaired.

Utah Field House of Natural History State Park Museum

The Utah Field House of Natural History State Park Museum is a museum in Vernal, Utah, United States.

Mowry Shale

The Mowry Shale is a Late Cretaceous geologic formation. The formation was named for Mowrie Creek, northwest of Buffalo in Johnson County, Wyoming.

<i>Uteodon</i> Genus of reptiles (fossil)

Uteodon is a genus of herbivorous iguanodontian dinosaur. It is a basal iguanodontian which lived during the late Jurassic period in what is now Uintah County, Utah. It is known from the middle of the Brushy Basin Member, Morrison Formation. The genus was named by Andrew T. McDonald in 2011 and the type species is U. aphanoecetes.

Earl Douglass Workshop-Laboratory United States historic place

The Earl Douglass Workshop-Laboratory was used by Earl Douglass, the discoverer of the dinosaur bone deposits at the dinosaur quarry in Dinosaur National Monument, to preserve, study and prepare fossil specimens. Located next to the quarry adjacent to the Quarry Visitor Center, the workshop is a 10.5-foot (3.2 m) by 13.17-foot (4.01 m) stone shed with a flat soil roof, built into the hillside. It was built about 1920 by Carnegie Museum of Natural History personnel who were working at the site in eastern Utah.

Paleontology in Utah Paleontological research in Utah

Paleontology in Utah refers to paleontological research occurring within or conducted by people from the U.S. state of Utah. Utah has a rich fossil record spanning almost all of the geologic column. During the Precambrian, the area of northeastern Utah now occupied by the Uinta Mountains was a shallow sea which was home to simple microorganisms. During the early Paleozoic Utah was still largely covered in seawater. The state's Paleozoic seas would come to be home to creatures like brachiopods, fishes, and trilobites. During the Permian the state came to resemble the Sahara desert and was home to amphibians, early relatives of mammals, and reptiles. During the Triassic about half of the state was covered by a sea home to creatures like the cephalopod Meekoceras, while dinosaurs whose footprints would later fossilize roamed the forests on land. Sand dunes returned during the Early Jurassic. During the Cretaceous the state was covered by the sea for the last time. The sea gave way to a complex of lakes during the Cenozoic era. Later, these lakes dissipated and the state was home to short-faced bears, bison, musk oxen, saber teeth, and giant ground sloths. Local Native Americans devised myths to explain fossils. Formally trained scientists have been aware of local fossils since at least the late 19th century. Major local finds include the bonebeds of Dinosaur National Monument. The Jurassic dinosaur Allosaurus fragilis is the Utah state fossil.

Echo Park Dam Dam in Northwestern Colorado

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 district of Dinosaur National Monument, flooding much of the Green and Yampa river valleys in the monument. The dam was bitterly opposed by preservationists, who saw the encroachment of a dam into an existing national park as another Hetch Hetchy, to be opposed as an appropriation of protected lands for development purposes. The Echo Park project was abandoned in favor of Glen Canyon Dam on the main stem of the Colorado, in lands that were not at that time protected. This was eventually regarded as a strategic mistake by conservation organizations.

Earl Douglass

Earl Douglass was an American paleontologist who discovered the dinosaur Apatosaurus, playing a central role in one of the most important fossil finds in North America. By 1922 Earl had unearthed and shipped more than 700,000 pounds of material including nearly 20 complete skeletons of Jurassic dinosaurs such as Diplodocus, Dryosaurus, Stegosaurus, Barosaurus, Camarasaurus and Brontosaurus.

Steamboat Rock (Colorado)

Steamboat Rock is a 6,074-foot (1,851-meter) elevation cape located in the Uinta Mountains, in Moffat County of northwest Colorado, United States. This iconic landmark of Dinosaur National Monument is situated at the confluence of the Green River and Yampa River. Precipitation runoff from this feature drains into the Green River. This geographical formation was originally named "Echo Rock" in John Wesley Powell's 1875 report, The Exploration of the Colorado River and Its Canyons. The Steamboat name first appeared on a 1941 United States Geological Survey map of Dinosaur National Monument. The area around it still retains the Echo Park name applied by Powell during the Powell Geographic Expedition of 1869.


  1. "Protected Area Profile for Dinosaur from the World Database of Protected Areas". protectedplanet.net. UN World Conservation Monitoring Centre and the IUCN . Retrieved September 7, 2021.
  2. 1 2 3 4 "Dinosaur National Monument Statistics". NPS. January 11, 2008. Retrieved 2009-03-21.
  3. "NPS Annual Recreation Visits Report". National Park Service. Retrieved 2017-05-09.
  4. 1 2 Hansen, Wallace (1969). The Geologic Story of the Uinta Mountains (USGS Bulletin 1291 ed.). U.S. Geological Survey.
  5. 1 2 3 Gregson, J.D., Chure, D.J., Sprinkle, D.A. (2010). "Geology and Paleontology of Dinosaur National Monument". Geology of Utah's Parks and Monuments. UGA Publication 28 (third edition) (Utah Geological Association): 161–192.
  6. April 22, on; 2019 (2019-04-22). "Dinosaur National Monument Designated as an International Dark Sky Park". International Dark-Sky Association. Retrieved 2019-07-05.CS1 maint: numeric names: authors list (link)
  7. "Rainbow and Island Parks". Dinosaur National Monument. National Park Service. Retrieved 14 December 2020.
  8. 1 2 3 PD-icon.svg This article incorporates  public domain material from the National Park Service document: "Fremont Culture". October 7, 2018. Retrieved January 29, 2020.
  9. PD-icon.svg This article incorporates  public domain material from the National Park Service document: "Viewing Petroglyphs and Pictographs". December 19, 2017. Retrieved January 29, 2020.
  10. Douglass, G.E. (2009). Iverson, Diane Douglass (ed.). Speak to the earth and it will teach you : the life and times of Earl Douglass, 1862-1931. Charleston, S.C.: BookSurge. ISBN   9781439244371.
  11. McPhee, John (1971). Encounters with the Archdruid. New York: Farrar, Straus and Giroux. p. 245. ISBN   0-374-51431-3.
  13. National Register of Historic Places in Moffat County American Dreams, Inc. Retrieved 2011-10-6.
  14. "Josie Bassett Morris Ranch Complex". National Archives Catalog. U.S. National Archives. Retrieved 13 December 2020.
  15. "Seasonal Temperature and Precipitation Information". Western Regional Climate Center. Retrieved May 3, 2013.
  16. Carpenter, K. 2018. Rocky Start of Dinosaur National Monument (USA), the World's First Dinosaur Geoconservation Site. Geoconservation Research 1(1)1-20.
  17. "Dinosaur National Monument Visitor Center Official Dedication Program Section". Vernal Express. May 29, 1958. Retrieved March 28, 2021.
  18. "Draft Environmental Impact Statement for Quarry Visitor Center, Part 1" (PDF). National Park Service. March 2007. Archived from the original (PDF) on 2007-06-11. Retrieved 2008-02-11.
  19. "$13.1M in stimulus cash revives dino monument". Salt Lake Tribune. April 2009. Archived from the original on 2012-03-22. Retrieved 2009-04-23.
  20. "Visiting The Quarry In Fall And Winter". National Park Service. November 2011. Archived from the original on 2011-12-29. Retrieved 2012-03-21.

Further reading