Dinosaur National Monument 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2006/008 

National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 

Dinosaur National Monument 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2006/008 

Geologic Resources Division 

Natural Resource Program Center 

P.O. Box 25287 

Denver, Colorado 80225 

March 2006 

U.S. Department of the Interior 

Washington, D.C.
The Natural Resource Publication series addresses natural resource topics that are of interest and 

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Printed copies of reports in these series may be produced in a limited quantity and they are only 

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sending a request to the address on the back cover. 

Please cite this publication as: 

Graham, J. 2006. Dinosaur National Monument Geologic Resource Evaluation Report. Natural Resource 

Report NPS/NRPC/GRD/NRR—2006/008. National Park Service, Denver, Colorado. 

NPS D-217, March 2006 
 DINO Geologic Resource Evaluation Report iii 

Table of Contents 

List of Figures .............................................................................................................. iv

Executive Summary ...................................................................................................... 1

Introduction ................................................................................................................... 3

Purpose of the Geologic Resource Evaluation Program ............................................................................................3

General Information....................................................................................................................................................3

Early Explorations.......................................................................................................................................................3

General Geologic Setting ...........................................................................................................................................4

Geologic Issues............................................................................................................. 8

Potential Geologic Hazards ........................................................................................................................................8

Other issues at Dinosaur............................................................................................................................................8

Mineral Resources......................................................................................................................................................9

Potential Geologic Research ......................................................................................................................................9

Interpretive Needs ....................................................................................................................................................10

Geologic Features and Processes............................................................................. 11

Dinosaur Quarry .......................................................................................................................................................11

Canyons ...................................................................................................................................................................11

Weber Sandstone and Steamboat Rock ..................................................................................................................11

Type Localities..........................................................................................................................................................11

Laramide Structures .................................................................................................................................................12

Geologic Association with Pikeminnow ....................................................................................................................12

Map Unit Properties .................................................................................................... 13

Map Unit Properties Table........................................................................................................................................14

Geologic History.......................................................................................................... 17

Precambrian .............................................................................................................................................................17

Paleozoic Era ...........................................................................................................................................................17

Mesozoic Era............................................................................................................................................................18

Cretaceous-Tertiary Laramide Orogeny ...................................................................................................................18

Cenozoic Era............................................................................................................................................................18

References................................................................................................................... 25

Appendix A: Geologic Map Graphic .......................................................................... 27

Appendix B: Scoping Summary................................................................................. 29

Attachment 1: Geologic Resource Evaluation Products CD
iv NPS Geologic Resources Division 

List of Figures 

Figure 1. Location Map of Dinosaur National Monument.. .............................................................................................5

Figure 2. Laramide tectonic map....................................................................................................................................6

Figure 3. Geologic time scale.........................................................................................................................................7

Figure 4. Precambrian orogenic belts ..........................................................................................................................20

Figure 5. Paleogeographic map of the Early Mississippian..........................................................................................21

Figure 6. Major uplifts and basins of the Pennsylvanian Period...................................................................................22

Figure 7. Paleogeographic map of the Late Triassic....................................................................................................22

Figure 8. Paleogeographic map of the Late Jurassic ...................................................................................................23

Figure 9. Cretaceous Interior Seaway..........................................................................................................................24
 DINO Geologic Resource Evaluation Report 1 

Executive Summary 

This report has been developed to accompany the digital geologic map produced by Geologic 

Resource Evaluation staff for Dinosaur National Monument. It contains information 

relevant to resource management and scientific research. 

Dinosaur National Monument (NM) is internationally 

known as a repository of significant fossil resources. 

Located on the Utah- Colorado border, Dinosaur NM is 

one of eight national park units established primarily for 

the protection of significant fossil resources. At Dinosaur 

these resources include the thousands of dinosaur bones 

that are now housed in the Dinosaur Visitor Quarry. 

These bones were entombed about 150 Ma during the 

Late Jurassic Period. They became part of the flat- lying 

strata that were later uplifted and tilted during the 

Laramide Orogeny to an angle of about 67o

. Today the 

bones form a spectacular display on one wall of the 

quarry. 

The Dinosaur Quarry is world- renown not only for the 

quantity of fossil material (over 350 tons of fossils and 

attached rock were removed from 1909 to 1924) but also 

for the quality of the dinosaur remains found there. 

Eleven different types of dinosaurs, from giant 

herbivorous Sauropods to voracious carnivores, have 

been discovered at the quarry. Several relatively 

complete, articulated skeletons have been removed from 

the quarry. The 21.79 m (71.5 ft) skeleton of Apatosaurus 

louisae (formerly known as Brontosaurus), for example, 

is one of the most complete dinosaur skeletons ever 

found. Bones found at Dinosaur NM come in a variety of 

sizes and shapes from the thick, dense thighbones of 

Sauropods to delicate, intact skulls, teeth, and tail tip 

vertebrae. The Dinosaur Quarry is a not only a 

remarkable sight for dinosaur enthusiasts but it also 

provides scientists new insights into dinosaur behavior 

and the ecosystem in which they lived. 

Dinosaur National Monument encompasses more area 

than just the Dinosaur Quarry, containing spectacular 

canyons cut by the Green and Yampa Rivers. Rather than 

flowing around the nose of the east- west trending Uinta 

Mountains, these rivers flow through the mountains 

exposing strata deformed during the Laramide Orogeny 

about 70- 40 Ma. Canyon walls reveal textbook examples 

of folded and faulted rocks formed during the past 2 

billion years. 

During the Late Jurassic and Cretaceous, volcanoes 

erupted on the western margin of the North American 

continent and ejected volcanic ash into the atmosphere. 

When the ash settled, it mixed with fine sediments and 

groundwater to form a type of clay called bentonite 

consisting mostly of the clay mineral montmorillonite. 

Bentonite has the capacity to accept water into its 

structure and swell when wet and to expel water from its 

structure and shrink upon drying. This shrink and swell 

capacity of bentonite can cause havoc with roads, 

buildings, and infrastructures such as pipelines and 

septic systems, presenting challenges to park managers. 

Current fluvial processes associated with the Green and 

Yampa Rivers may also present challenges due to erosion 

and flash flooding. Cliffs carved into the Weber 

Sandstone may be undercut, causing cliff collapse. Cliff 

collapse, erosion, and sediment influx from tributary 

streams create ever- changing fluvial geomorphic 

landscapes that demand the attention of park resource 

management. 

A Geologic Resources Inventory workshop held at 

Dinosaur in 1998 identified issues of primary importance 

to resource managers. These issues included: 

• Slumps in existing Morrison Formation landslide 

materials along the Harpers Corner road creating 

maintenance and traffic hazards 

• Green River cutbank erosion into the Mancos Shale 

along the quarry entrance road near the park 

boundary 

• Cub Creek incision of several meters into older valley 

fill deposits where the road crosses the stream 

• Green River cutbank erosion and the relocation 

options for the Echo Park campground 

• Expanding, contracting, and shifting Morrison 

Formation substrate causing damage to the Quarry 

Visitor Center 

• Foundation movement issues at the Headquarters 

building in Colorado 

• The need for a geologic hazards map 

Research needs and potential research projects were also 

discussed at the workshop and included: 

• Association of rare plants with certain geologic strata 

and geomorphic surfaces 

• Comprehensive, multidisciplinary study of the Cedar 

Mountain Formation to gain significant understanding 

of the paleoenvironments of that time period 

• Long- term preparation and curation of specimens 

• Hydrogeology and geomorphology of Cub Creek and 

other stream restoration projects 

• Juniper tree age dating and correlation to the past 

climate record 
2 NPS Geologic Resources Division 

Geologic features of importance to staff at Dinosaur NM 

include the following: 

• Dinosaur quarry 

• Other localities of type specimens of fossils 

• The canyons of Dinosaur 

• Weber Sandstone and Steamboat Rock 

• Type Localities of the Lodore Formation and Brown’s 

Park Formation 

• Laramide Structures 

From Split Mountain to Lodore Canyon and the Yampa 

Plateau, the strata in Dinosaur display a record of 

geologic time that spans about 2 billion years. Dinosaur 

National Monument contains one of the most complete 

stratigraphic columns exposed in the National Park 

System. The Uinta Mountains contain significant clues to 

the structural history of the Rocky Mountains as well. 

The rocks are primarily sedimentary and they contain 

significant information that reveals and helps unravel the 

complex and dynamic history of Earth. 
 DINO Geologic Resource Evaluation Report 3 

Introduction 

The following section briefly describes the regional geologic setting and the National Park 

Service Geologic Resource Evaluation Program. 

Purpose of the Geologic Resource Evaluation Program 

Geologic resources serve as the foundation of park 

ecosystems and yield important information for park 

decision making. The National Park Service Natural 

Resource Challenge, an action plan to advance the 

management and protection of park resources, has 

focused efforts to inventory the natural resources of 

parks. The geologic component is carried out by the 

Geologic Resource Evaluation (GRE) Program 

administered by the NPS Geologic Resources Division. 

The goal of the GRE Program is to provide each of the 

identified 270 “Natural Area” parks with a digital 

geologic map, a geologic evaluation report, and a 

geologic bibliography. Each product is a tool to support 

the stewardship of park resources and each is designed to 

be user friendly to non- geoscientists. 

The GRE teams hold scoping meetings at parks to review 

available data on the geology of a particular park and to 

discuss the geologic issues in the park. Park staff are 

afforded the opportunity to meet with the experts on the 

geology of their park. Scoping meetings are usually held 

for individual parks although, some meetings address an 

entire Vital Signs Monitoring Network. 

General Information 

Dinosaur National Monument straddles the UtahColorado border in northwest Colorado and northeast 

Utah (figure 1). The Monument covers about 210,278 

acres (328 sq. mi. or 852 sq. km.). Visitation in fiscal year 

2002 was 299,622. Dinosaur NM is both a park with a 

world- famous dinosaur quarry that most people come to 

visit, and also a park with spectacular canyons of the 

Green and Yampa rivers. 

The Dinosaur Quarry Visitor Center is located north of 

the Green River in Utah. The Quarry is 11 km (7 mi) north 

of Jensen, Utah, on Utah State Highway 149. Thousands 

of dinosaur bones that were entombed 150 Ma during the 

Late Jurassic Period have been discovered in this area of 

the park. Dinosaur NM is one of eight National Park 

Service units established primarily to protect significant 

fossil resources. 

Monument Headquarters and Visitor Center are located 

1.6 km (1 mi) east of the town of Dinosaur, Colorado, just 

off U.S. Highway 40. There are no dinosaur bones in this 

part of the park. The Visitor Center provides information 

to the public about the quarry and about the canyon 

country of the park. 

Early Explorations 

At least 7,000 and perhaps 10,000 years ago, paleoIndians hunted big game in the Dinosaur region. About 

1,800 years ago, the Fremont culture entered the area and 

grew corn, beans, and squash as well as engaging in 

hunting and gathering. They stayed until drought and 

crop failures drove them out about 700 years ago (Kiver 

and Harris, 1999). In addition to rock shelters and 

numerous other artifacts in the monument, the Fremont 

people left spectacular pictographs and petroglyphs on 

rock walls in the monument. 

The Shoshone, who also practiced a hunting and 

gathering lifestyle, were the first people to reoccupy the 

area a few hundred years ago. In 1825 William Ashley 

floated through the dangerous canyons of the Green 

River with a small party of trappers. They were the first 

individuals known to do so. Major John Wesley Powell 

repeated the feat in 1869 and continued down the Green 

River to its confluence with Colorado River. He and his 

men were the first to navigate both canyons of the Green 

and Colorado rivers. 

In the late 1800s, the American public became enamored 

with the remains of dinosaurs. Paleontologists eagerly 

explored the western United States looking for bones to 

take back to their respective colleges, universities, or 

museums. The treachery, competition, and frantic desire 

to find (and name) the next unique species during these 

“Dinosaur wars” make for interesting reading. 

In 1908 Earl Douglas and W.J. Holland, director of the 

Carnegie Museum, found a magnificent dinosaur 

thighbone and other evidence of dinosaurs in 

northeastern Utah. Douglas returned the following year 

to the Uinta Mountains and spent months scouring the 

countryside, but he found no extraordinary bone 

deposit. 

On August 19, 1909, Douglas found eight large, 

articulated dinosaur vertebrae in the exact position they 

had occupied in the living animal. These eight bones 

were the first of thousands that would eventually be 

removed from the greatest dinosaur quarry ever 

discovered. 

Prior to Douglas’ discovery, very few dinosaur bones had 

been found intact and even fewer complete skeletons 

had been uncovered. Douglas’ dinosaur proved to be an 

Apatosaurus of exceptional size and completeness. His 

discovery proved for the first time that Apatosaurus had a 

very long tail with a so- called “whip lash” on the end. 

This anatomical surprise was one of many that 

revolutionized dinosaur paleontology. 

Several years after operations began at the quarry, the 

government opened the area for settlement. To Douglas, 

Holland, and their associates, this meant that a 

speculator could locate a claim on the quarry property 
4 NPS Geologic Resources Division 

and acquire its vast bone deposits for private gain. 

Douglas filed a claim on behalf of the Carnegie Museum 

for the mineral rights to the land, but government 

officials disallowed the claim on the grounds that 

dinosaur bones could not be considered minerals in 

nature under the General Mining Law of 1872. Holland 

traveled to Washington, D.C., to confer with his old 

friend Charles Doolittle Walcott, a renowned 

paleontologist who also happened to be the Secretary of 

the Smithsonian Institution. 

Walcott brought this issue to the attention of President 

Woodrow Wilson and on October 4, 1915, President 

Wilson set aside 80 acres surrounding the quarry as a 

national monument. In 1938, the monument was 

expanded to include the rugged canyons of the Green 

and Yampa rivers. 

With the financial support of Andrew Carnegie, Douglas 

collected more than 350 tons of dinosaur bones and 

other fossils from the dinosaur quarry from 1909 to 1923. 

When the Carnegie operations ceased, the Smithsonian 

Institution was invited to remove some remaining 

important groups of bones, and in 1923, they shipped 33 

boxes of fossil bones to Washington. Also in 1923, 

Douglas supervised teams from the University of Utah 

that removed an Allosaurus skeleton, a partial skeleton of 

a juvenile Sauropod, parts of two Stegosaurus skeletons, 

and an excellent Barosaurus skeleton (McIntosh, 1977). 

Construction of the Dinosaur Quarry Visitor Center 

began in 1957 and it was opened to the public on June 1, 

1958. 

Technicians at the park, Jim Adams and Tobe Wilkins, 

uncovered and prepared the dinosaur bones that the 

visitors see today. Over 2000 bones stand out in relief on 

the quarry face, thanks in large part to the dedication and 

perseverance of these two individuals. 

General Geologic Setting 

Dinosaur National Monument is located on the eastern 

end of the Uinta Mountains, a broad anticline formed 

during the Laramide Orogeny (about 70- 40 Ma). The 

Uinta Mountains are the topographic expression of a 

regional anticline or arch, known as the Uinta arch. They 

contain abundant folds and faults that developed during 

the Laramide mountain building event (figure 2). The 

Uinta Mountains are also one of the few east- west 

trending mountain ranges in the western United States. 

Erosion by the Green and Yampa rivers cut the canyons 

in the monument and exposed folded and faulted rocks 

formed during the past 2 billion years (Kiver and Harris, 

1999). Seeming to defy logic, the Green and Yampa rivers 

converge at the east end of the Uinta Mountains and flow 

through the mountain structure rather than around the 

topographically lower east end of the mountains. 

The Green River is interpreted as a superposed stream 

(Hanson, 1986). The Green and Yampa rivers cut 

sinuous, meandering stream channels into the flat- lying 

Tertiary strata that had buried the older Uinta arch. 

When they encountered the folded strata in the anticline, 

the streams continued to cut down through the soft 

sedimentary rocks. Eventually the meanders became 

entrenched, and the rivers continued to cut down 

through the dense, hard rocks of the Precambrian core of 

the anticline. 

Precambrian, Paleozoic, and Mesozoic strata are found 

at Dinosaur National Monument. The billion- year- old 

Uinta Mountain Group, consisting of metasediments, are 

exposed in the core of the Uinta arch and the Paleozoic 

and Mesozoic strata are laid out like pages of a book on 

the flanks of the eroded anticline. Dinosaur bones are 

primarily found in the Jurassic- age (about 150 Ma) 

Morrison Formation. 
 DINO Geologic Resource Evaluation Report 5 

Figure 1. Location Map of Dinosaur National Monument. 
6 NPS Geologic Resources Division 

Figure 2. Laramide tectonic map showing the basement-cored arches and Thrust Belt that borders the Colorado Plateau to the west. 

Modified from Gregson and Chure (2000). 
 DINO Geologic Resource Evaluation Report 7 

Figure 3. Geologic time scale. Red lines indicate major unconformities between eras. Absolute ages shown are in millions of years. Scale is 

from the United States Geological Survey. 
8 NPS Geologic Resources Division 

Geologic Issues 

A Geologic Resource Evaluation scoping session was held for Dinosaur National 

Monument, August 10- 11, 1998, to discuss geologic resources, to address the status of 

geologic mapping, and to assess resource management issues and needs. The following 

section synthesizes the scoping results, in particular, those issues that may require 

attention from resource managers. 

Potential Geologic Hazards 

A geologic resources workshop held at Dinosaur 

National Monument in 1998 (Appendix B) identified the 

following geologic hazards that affect the monument. 

These hazards are especially significant with regards to 

maintenance of park roads and buildings. 

• Slumps 

• Stream bank erosion 

• Stream incision 

• Bentonitic soils 

Other issues at Dinosaur 

• Abandoned mine workings 

• Caves 

• Adjacent mineral development 

Slumps in existing landslide materials create 

maintenance and traffic hazards in several areas along 

the Harpers Corner road. Landslide material is mostly 

derived from the Jurassic Morrison Formation. To 

alleviate this problem, Dinosaur maintenance is 

considering relocating the roadways to the crests of 

associated ridges. 

Mancos Shale forms the relatively flat plain leading into 

the dinosaur quarry in Utah. The Green River is actively 

eroding its cutbank along the quarry entrance road near 

the park boundary. Maintenance staff at Dinosaur NM 

have been armoring the eroded areas with riprap in an 

attempt to stall further cutbank erosion, but only for a 

limited time. 

At the workshop, the “only permanent solution” 

discussed was to move the road to the opposite bank of 

the Green River, a solution with engineering and political 

issues. Stream restoration projects throughout the 

country, including one on the Yampa River in Steamboat 

Springs, Colorado, have shown that bank erosion can be 

controlled while sustaining the ecological health of a 

stream by relocating the channel of the river away from 

the cutbank, eliminating cutbank erosion. Park 

management may wish to consider a stream restoration 

project as a possible solution for Green River erosion. 

The existing campground at Echo Park is also located on 

a cutbank of the Green River just below its confluence 

with the Yampa River. Participants at the workshop 

discussed the possibility of relocating the campground 

away from the river on the west side of Pool Creek 

Canyon to take advantage of the tree cover. This 

location, however, has a greater risk of flash floods and 

debris flows. A second alternative site is available on the 

east side of the creek and canyon, but unfortunately, this 

second site has no tree cover. 

Cub Creek has incised its channel several meters into 

older valley fill deposits where the Cub Creek road 

crosses the stream. In the spring of 1998, high stream flow 

eroded around the end of a beaver dam upstream and 

flow was directed against the Cub Creek road 

embankment. Park maintenance redirected the flow back 

to the main channel through a culvert under the road and 

armored the upstream portion of the roadbed with 

riprap. Nevertheless, the stream rapidly silted- in 

upstream of the barrier, indicating that, although 

entrenched, the stream still carries a high sediment load. 

A comprehensive study of the hydrology and 

geomorphology of this area would aid in restoring the 

channel geometry and fluvial regime existing prior to 

entrenchment. 

Expanding, contracting, and shifting substrate beneath 

the Quarry Visitor Center has caused major damage to 

the building. Although the quarry face appears to be 

stable, the central part of the structure is sinking and has 

sustained offsets ranging from several inches to a foot or 

more. The obvious floor deformation and tilting of 

support beams and windows suggest that the structural 

integrity of the building has been compromised. The 

building is located on the Morrison Formation which 

contains bentonite, a clay that swells and contracts in 

response to changes in water content. 

Park maintenance has attempted to isolate the plumbing 

in the building and to keep the roof in good condition to 

limit the amount of water that can infiltrate under the 

building, but the problem persists. The spiral walkway 

has been reinforced but must continually be monitored 

for movement. Swelling clays have also deformed the 

parking lot and sidewalk outside the building. A 

comprehensive engineering study has never been 

undertaken. The quarry building is a historic structure, 

therefore approval must be obtained for any 

architectural modifications. Although less severe, similar 

foundation and movement issues exist at the 

headquarters building. 

A geologic hazards map is needed for park planning and 

maintenance staff. This was discussed at the workshop 

but not in detail. 
 DINO Geologic Resource Evaluation Report 9 

Two abandoned mines have been identified in Dinosaur. 

The Mantle Mine, an abandoned copper mine, had four 

adits and two shafts associated with it. These were 

blasted closed by the State of Colorado in 1988. There are 

two “outlier” openings. One is apparently a very short 

adit considered hazardous because of unstable rock. 

Another adit is near an access road. Although the area is 

in a remote part of the park with little visitation, both of 

these openings may need to be closed. 

Another mine opening, the Shepard Mine, was identified 

on a map as being west of and “several draws over from” 

the Mantle Mine (Burghardt, per. com). These should be 

examined for possible closure in the future. Bat habitat 

does not appear to be an issue at either mine. 

There are reports of several caves in Dinosaur NM. One 

cave has been explored to a distance of 1000 feet (300 m) 

but apparently it continues on. Access to another cave is 

deemed treacherous and at least one cave is known to 

contained archeological materials. One of the caves has 

been partially mapped in a cursory way. 

In spite of these reports and the acknowledged large 

exposures of limestone rock in the monument, there has 

been no systematic search to locate and evaluate the 

number, distribution, and significance of caves in 

Dinosaur. Present knowledge of the caves in the 

monument is spotty and anecdotal. Dinosaur National 

Monument has asked for technical assistance to develop 

a cave management plan for known cave resources and 

develop funding requests for a comprehensive inventory 

of caves in the monument. The need for a cave inventory 

and assessment of paleontological resources was 

identified in the 2005 draft Paleontological Resource 

Review, Management and Research Plan, for Dinosaur 

National Monument. 

Mineral Resources 

Federal mineral leasing is prohibited within the 

boundaries of Dinosaur National Monument as is the 

location of new mining claims. Approximately 4,500 

acres in the park are non- federally owned and could 

potentially be the subject of proposals to develop private 

mineral rights. If that occurred, the NPS would regulate 

that activity. However, no mineral production on this 

acreage is taking place at this time. 

Coal 

Coal is present in the vicinity of the park; however, there 

has been no federal coal leasing immediately adjacent to 

the park. In the late 1980’s several Preference Right 

Leases for coal were issued in an area located over 10 

miles south of the park, but information on the current 

status of these leases is unavailable. 

Oil and Gas 

Also in the late 1980’s, Conoco Inc., drilled the “Blue 

Mountain Unit #1- A” exploratory oil and gas well on 

BLM lands directly adjacent to the Harpers Corner Road 

scenic easement. The well did not produce and was 

subsequently plugged and abandoned. More recently, 

the Bureau of Land Management has been actively 

engaged in issuing oil and gas leases on BLM 

administered lands immediately west of the Harpers 

Corner Road and also south of the Monument 

headquarters near Dinosaur, Colorado. After consulting 

with the NPS, BLM indefinitely deferred oil and gas 

leasing within 1⁄2 mile of the park headquarters and 

further agreed to a 1200 foot setback for leases adjacent 

to the Harpers Corner Road scenic easement. The BLM 

agreed to enforce a “Visual Resource Management Level 

2” designation for this area. Numerous oil and gas wells 

have been drilled further west of the Harpers Corner 

Road in Utah, but are still in the viewshed of the park. 

Oil Shale 

The BLM is preparing to amend existing applicable 

Resource Management Plans to address oil shale and tar 

sands resources leasing in Wyoming, Colorado and Utah. 

Although tar sands do not occur in the vicinity of 

Dinosaur National Monument, the park is literally 

surrounded by oil shale basins. Oil shale leasing may 

occur to the northwest of Dinosaur in the Green River 

Basin (Wyoming), to the northeast in the Washakie Basin 

(Wyoming), to the southwest in the Uinta Basin (Utah), 

and to the Southeast in the Piceance Creek Basin 

(Colorado). 

Potential Geologic Research 

In addition to the need for a geologic hazards map, there 

is also a need for a hydrology and geomorphology study 

of Cub Creek, and a comprehensive geologic engineering 

study of the Morrison clays. The following research 

needs were discussed at the 1998 workshop: 

• Association of rare plants with certain geologic strata 

• Comprehensive, multidisciplinary study of the Cedar 

Mountain and correlative formations 

• Storage facilities for paleontological specimens 

Tamara Naumann, botanist at Dinosaur NM, noted the 

association of rare plants with certain geologic strata and 

geomorphic surfaces using the rare Ute Ladies- Tresses 

Orchid as an example. The rare orchids grow in Lodore 

Canyon and show a strong correlation with geomorphic 

surfaces formed under the flow regime established by 

discharge from Flaming Gorge dam. Increased flows 

from Flaming Gorge have been proposed to assist the 

endangered fish in the Green River. The affect of 

increased flow on the orchid population is unknown. In 

1998, further research was needed to determine the effect 

of flooding on the existing surfaces and plants, as well as, 

how and if these flows might create new habitat for the 

orchid. 

In recent years, dinosaur fossils have been found in the 

Lower Cretaceous Cedar Mountain Formation. A 

comprehensive, multidisciplinary study of the Cedar 

Mountain Formation and its correlative formations 

would help define the paleoenvironments of that time 

period. Research into the sedimentology, stratigraphy, 

palynology, pedology, invertebrate paleontology and 

paleobotany of the Cedar Mountain Formation would 

greatly enhance the understanding of the new quarry. 
10 NPS Geologic Resources Division 

Although not discussed in the 1998 meeting, other issues 

of interest to Dinosaur staff include: a need for geological 

and paleontological studies of the Lower Cretaceous 

Dakota Sandstone, and the Upper Cretaceous Mowry 

Shale and Frontier Sandstone; geological studies of the 

Triassic Moenkopi Formation and of the Lower Jurassic 

Glen Canyon Formation; and an inventory of the Upper 

Jurassic Chinle Formation. 

Fossil specimens are prepared in the Quarry Visitor 

Center. The ever- growing collection of fossils has put a 

strain on this storage facility. There have been a number 

of engineering studies of the structural problems 

discussed above, but the building continues to 

deteriorate. Plans are underway to either rehabilitee or 

rebuild all or part of the structure to provide the 

infrastructure for preparation, curation, research, 

resource management, and inventory and monitoring of 

the fossil collections. Other fossils are stored in sheds or 

the basement of the headquarters building more than 20 

miles away. These storage facilities are improperly 

ventilated creating a hazard by the buildup of radon gas, 

a product of the radioactivity associated with many 

specimens. 

Interpretive Needs 

Specific interpretive issues were not discussed in detail at 

the workshop, but several resources associated with 

geology included: 

• The Morrison Initiative: Christine Turner and Fred 

Peterson of the USGS worked on the Morrison 

Initiative. Their comprehensive report is complete and 

available to Dinosaur staff. 

• Christine Turner and Fred Peterson also discussed the 

need for a geologic guidebook and road log linking 

Permian formations among various parks and other 

sites on the Colorado Plateau. 

• Several interpretive publications related to the geology 

of Dinosaur NM are available in the monument 

bookstores and mentioned in the workshop scoping 

report (Appendix B). 
 DINO Geologic Resource Evaluation Report 11 

Geologic Features and Processes 

This section provides descriptions of the most prominent and distinctive geologic features 

and processes in Dinosaur National Monument. 

Dinosaur Quarry 

Preservation of the dinosaur quarry was the impetus for 

the creation of Dinosaur National Monument. The eight 

articulated tail vertebrae of Apatosaurus that Dr. Earl 

Douglas saw projecting from the Morrison ridge led to 

the discovery of the remains of over 400 individuals, 

making this quarry one of the greatest dinosaur localities 

ever found. 

There are three layers of bones at Dinosaur NM. Bones 

in the first layer were generally extracted for museums 

and exhibits. The second layer is mostly what exposed at 

the quarry and cliffs at Dinosaur. The third layer has not 

been as fully developed as the others. The orientation of 

the bones as well as the sedimentology of the layers 

indicates that the dinosaurs were preserved in a fluvial 

environment. Much like bison carcasses that collected in 

the meanders of the Missouri and Platte Rivers during 

flooding season, dinosaurs were log- jammed in the 

rivers in Morrison time - either caught in floods or 

drowned in some other way. Sediment carried by the 

floods rapidly buried the bones, resulting in the excellent 

preservation seen today. The femurs, vertebrae, and 

other large limb bones are oriented parallel to flow and 

there is segregation of large bones from smaller digit 

bones. These smaller bones (like twigs) were transported 

farther down stream than the larger bones. This 

segregation of bone size can be seen in the quarry. 

Some of the bones are very small, such as the ear bone 

that proved dinosaurs could actually hear (first found at 

Dinosaur NM). Yet some of them are in close 

approximation to larger bones, which may or may not 

have been from the same animal. The wear on some 

bones looks as though they traveled some distance while 

others appear fresh, as if the animals drowned and were 

buried on the spot. For more information on the history 

of Dinosaur Quarry and the paleontology of the 

monument please refer to the Paleontology section of 

Gregson and Chure (2000) and to the paleontology 

summary paper by Santucci (2000). 

Canyons 

Recognized as two of the great river gorges of western 

North America, the canyons of the Green and Yampa 

Rivers each possess their own unique character. The 

Canyon of Lodore, cut by the Green River, exposes red 

rocks of the Precambrian Uinta Mountain Group for 

most of its length. These reddish cliffs tower 600 m 

(2,000 ft) above the surface of the river. Exposures of 

Weber Sandstone dominate the precipitous walls of 

Yampa Canyon. One cliff, called the Grand Overhang by 

river runners, is 330 m (1,100 ft) high and exposes the 

entire thickness of the Weber. The cliff is an undercut, 

overhanging wall of sandstone located within the deeply 

entrenched gooseneck meanders of the Yampa River 

below Harding Hole (Hansen, 1996; Gregson and Chure, 

2000). 

Other unique and spectacular canyons include Split 

Mountain Canyon, Whirlpool Canyon, and Jones Hole. 

As the name implies, Split Mountain is split by the Green 

River, which has exposed a unique cross- sectional 

perspective of the Split Mountain anticline. As it flows 

through Split Mountain, the Green River drops an 

average of 3.7 m per km (19.5 ft per mi.), the steepest 

gradient of any other canyon in Dinosaur. The contact 

between the Uinta Mountain Group and the overlying 

Lodore Sandstone is exposed in Whirlpool Canyon, a 

canyon that the Green River has cut through the uplifted 

Mitten Park structural block, exposing the Mitten Park 

and Island Park faults as well. At this contact, are fossil 

sea stacks about 55 m (180 ft) high which were buried by 

the sediments of the Cambrian Lodore sea more than 

500 Ma (Hansen, 1996). 

Downstream lies Jones Hole, an extended, steep- walled 

canyon. Jones Creek emerges abruptly from openings in 

the Round Valley Limestone about 6.5 km (4 miles) 

above its confluence with the Green River in Whirlpool 

Canyon. Upper Jones Hole follows the Island Park fault 

trace from the Jones Creek springs down to its 

confluence with Ely Creek, a smaller tributary stream. 

The fault places Cambrian- age Lodore strata against 

Pennsylvanian- age rocks. 

Weber Sandstone and Steamboat Rock 

The Weber Sandstone almost always forms towering 

landforms where it is exposed. The best known of these 

is Steamboat Rock in Echo Park. This enormous 

sandstone monolith towers 320 m (1,050 ft) above the 

Green River and is more than a mile long (Hansen, 1996). 

Erosion by the Green River on the inner side of an 

entrenched meander formed Steamboat Rock and 

carved the outer canyon walls of Echo Park (Gregson 

and Chure, 2000). The Weber Sandstone also forms the 

hogbacks, flatirons, and box canyons that are a part of 

Split Mountain and the south side of Blue Mountain. 

Although exposed at the surface in the monument, the 

Weber Sandstone dips into the subsurface south of Blue 

Mountain outside of the monument. In the subsurface, 

the Weber Sandstone is the primary reservoir rocks of 

the giant Rangely Oil Field southeast of the monument. 

Type Localities 

A type locality is an area where exposed strata are first 

definitively described and documented by geologists. 

Two formations have their type localities within or near 

Dinosaur National Monument. The type locality of the 

Lodore Formation is located at the southern end of 
12 NPS Geologic Resources Division 

Lodore Canyon near Limestone Draw. This site is about 

4 km (2.5 mi) upstream from Echo Park and the 

confluence of the Green and Yampa Rivers. Major John 

Wesley Powell first named the formation as the Lodore 

Group in 1876. The Browns Park Formation has its type 

locality in Browns Park, Colorado and Utah. In 1876 John 

Wesley Powell also was the first to use the name Browns 

Park Formation. 

Laramide Structures 

“The Dinosaur area contains some of the best exposures 

of Laramide- age faults and folds found anywhere within 

the Rocky Mountains,” (Gregson and Chure, 2000). 

Exposures of Laramide- age structures range from highangle normal faults to classic low- angle thrust faults. 

Fold shapes range from classic cylindrical to quite 

angular and kink- like folds. Thrust faults are exposed at 

Hells Canyon and Mitten Park. Cylindrically- folded 

strata at Mitten Park become tight, kink- like folds just a 

few miles south at the Ruple Point- Red Rock anticline. 

Analysis of structures in Dinosaur NM has supported a 

variety of tectonic theories and models through the 

years. See Gregson and Chure (2000) for a list of 

references. 

Geologic Association with Pikeminnow 

The spawning sites of the Colorado Pikeminnow 

(formerly called squawfish) in the Lower Yampa Canyon 

appear to be associated with geologic structure and 

lithology. The bedrock- incised channel bottom of the 

Lower Yampa has formed in response to downstream 

folding. The pikeminnow spawn on bank- attached and 

mid- channel bars at three locations in the canyon, which 

is located on the east- dipping flank of a northeasttrending anticline. Furthermore, the contact between the 

Weber Sandstone and the limestone of the underlying 

Morgan Formation are the discharge sites of carbonate –

rich seeps and springs. Water conductivity is higher 

where these spawning bars are located (Mussetter and 

Harvey, 1999). 
 DINO Geologic Resource Evaluation Report 13 

Map Unit Properties 

This section provides a description for and identifies many characteristics of the map 

units that appear on the digital geologic map of Dinosaur National Monument. The table 

is highly generalized and is provided for informational purposes only. Ground 

disturbing activities should not be permitted or denied on the basis of information 

contained in this table. More detailed unit descriptions can be found in the help files that 

accompany the digital geologic map or by contacting the NPS Geologic Resources 

Division. 

This section explains specific properties associated with 

the geologic formations that have been identified and 

mapped in the park. The properties of specific units may 

be informative when making management decisions. 

Geologic features and processes are often specific to a 

particular stratigraphic unit (group, formation, or 

member). 

Dinosaur NM offers one of the most complete 

stratigraphic columns exposed within the National Park 

System (Untermann and Untermann, 1969; Hansen, 1977; 

Gregson and Chure, 2000). Except for the Ordovician, 

Silurian, and Devonian, all of the geologic periods (figure 

3) are represented in the Dinosaur NM area. Almost all 

of the rocks exposed in the area are sedimentary and 

range in age from Precambrian (about 1,100 Ma) to 

Miocene (about 25 to 10 Ma) (Hansen and others, 1983; 

Hansen, 1986a, 1986b; Gregson and Chure, 2000). The 

Quaternary Period is represented by unconsolidated 

alluvium. 

Precambrian strata are exposed in the northern part of 

the monument, in the Lodore Canyon area. Upper 

Paleozoic strata form the core of the Split Mountain and 

Red Rock anticlines. Mesozoic rocks flank these 

anticlines. 

The following Map Unit Properties Table identifies 

properties specific to each unit present in the 

stratigraphic column including: map symbol, name, 

description, topographic expression, resistance to 

erosion, suitability for development, hazards, potential 

paleontologic resources, mineral resources, and global 

significance.
Map Unit Properties Table 

Age Unit Name (Symbol) Lithology and Description Topographic Expression Erosion Resistance Suitability for Development Ha

Quaternary Unconsolidated material (Q) Highly variable; includes alluvial, landslide, terrace and gravel deposits, eolian sand, talus, and debris fan deposits; variable thickness Variable Low Variable Debris 

potenti

Major Regional Unconformity 

Browns Park Formation (Tbp) 

Variable; primarily sandstones and unconsolidated tuffs with minor chert, limestone, siltstone, conglomerate, and mudstone; 600 ft (490 m) thick 

Forms Browns Valley north of Gates of Ladore Variable 

Some lake clay and volcanic deposits; some floodplain 

Tertiary Bishop 

Conglomerate (Tb) 

Light gray to pinkish- gray to tan, poorly sorted, loosely cemented, pebble, cobble, boulder conglomerate and coarse- grained sandstone; 200-500 ft (60- 150 m) thick to very thin due to postBishop erosion 

Local outcrops on Blue Mountain, Yampa Plateau, Ruple Ridge, trail to Harpers Corner, near Jones Hole, and drainages of Diamond Gulch and Pot Creek 

Loosely cemented 

Isolated deposits; probably not an issue with regards to development 

Major Regional Unconformity 

Mesaverde Group  (Kmv) 

Transitional from marine and near- shore sandstone and shale to lagoon, swamp, and continental sandstone with coal in upper part: 2600 ft (800 m) thick 

Ridge former; Not exposed in Dinosaur Variable Not exposed in Dinosaur Not ex

Sego Sandstone  (Kmvs) 

Gray marine shale with fossiliferous (Baculites) dolomite concretions; 0- 250 ft (0- 75 m) thick 

Ridge former; Not exposed in Dinosaur Moderate Not exposed in Dinosaur Not ex

Buck Tongue, Mancos Shale  (Kmb) 

Thickness: 200- 500 ft (60- 150 m) Slope former; Not exposed in Dinosaur Low Not exposed in Dinosaur Not ex

Castlegate Sandstone  (Kc) 

Gray marine shale with fossiliferous (Baculites) dolomite concretions; thickness: 0- 100 ft (0- 30 m) 

Ridge former; not exposed in Dinosaur Moderate Not exposed in Dinosaur Not ex

Mancos Shale  (Km) 

Dark gray, silty to clayey, marine shale that weathers light gray to light yellow; minor siltstone and sandstone in upper part with layered bentonite and a few limestone beds in the lower part; locally fossiliferous; thickness : 4800- 5600 ft (1450- 1700 m) 

Slope and valley former 

Low: landslide potential; cutbank erosion along streams and rivers 

Bentonite clay may cause problems 

Slippery Swellin

Frontier Sandstone (Kmf) 

Upper part: light- brown to light- greenish- gray, thin- bedded to massive, fine- grained calcareous sandstone; locally cross- bedded with ripple marks; Lower part: dark- gray, fossiliferous, calcareous shale, silty shale, and siltstone; 100- 300 ft (30- 90 m) thick 

Upper part: hogbacks & flatirons; Lower unit: slopes & saddles 

Upper part: resistant to erosion; Lower part: low resistance 

Development on hogbacks will impact viewscape 

Pot

Upper Cretaceous 

Mowry Shale  (Kmm) 

Hard, gray, fissile, siliceous shale; 33- 220 ft (10- 65 m) thick 

Forms narrow strike valley between Dakota Sandstone and Frontier Sandstone 

Low: forms valleys Bentonitic soils Slippery 

Dakota Sandstone  (Kd) 

Light- gray to yellow, cross- bedded, medium- to coarse- grained to pebbly sandstone and minor pebble conglomerate with subordinate black carbonaceous shale; 40- 100 ft (12- 30 m) thick 

Forms hogbacks Highly resistant 

Development on hogbacks will impact viewscape 

Pot

Lower 

Cretaceous Cedar Mountain 

Formation  (Kcm) 

Colorful clay- and siltstone, some sandstone; local conglomerate (Buckhorn Conglomerate); 0- 200 ft (0- 60 m) thick 

Erodes with Morrison to form strike valleys & low ridges 

Mudstone & siltstone have a lower resistance than sandstones 

Similar to Morrison Fm. Similar 
Age Unit Name (Symbol) Lithology and Description Topographic Expression Erosion Resistance Suitability for Development Ha

Morrison Formation  (Jm) 

Multi- colored mudstone and siltstone, with bentonite, sandstone, and conglomerate; dinosaur fossils; 650- 1000 ft (200- 300 m) thick 

Mudstones form slopes; sandstones tilted into hogbacks 

Mudstones have a low resistance & landslide potential; sandstones are more resistant to erosion 

Shifting substrate; bentonite in mudstone 

Mudstowhen wbentoni

Stump Formation  (Js) 

Redwater mbr: light- green to olive- green, fissile, 

glauconitic siltstone and shape with sparse interbeds of tan, lavender, or greenish- gray crossbedded, glauconitic, oolitic, fossiliferous limestone and sandstone; thins from about 130 ft (40 m) in the western part to 70 to 90 ft (22- 27 m) in the east. Curtis mbr: light- gray to light- greenish- gray, 

thin- to medium- bedded, cross- bedded, medium- to coarse- grained sandstone; ripple marks locally and fossiliferous; thins from about 50- 100 ft (15- 30 m) in western Dinosaur to about 23 ft (7 m) at Deerlodge Park 

Redwater mbr: forms slopes; Curtis mbr: forms ledges 

Redwater mbr: softer, less 

resistant to erosion. Curtis mbr: more resistsnt 

None 

documented 

Entrada Sandstone  (Je) 

Pink to yellow- gray, fine- to medium- grained quartz sandstone with eolian cross- bedding; thins eastward from 165 ft (50 m) at Dinosaur Quarry to 40 ft (12 m) at Deerlodge Park 

Cliff former but outcrops are more subdued than Glen Canyon Sandstone 

High 

Development on Entrada will impact viewscape 

Carmel Formation  (Jca) 

Dark- red sandy siltstone and mudstone; thickens westward and pinches out toward the east, ranging from about 130 ft (40 m) thick near Island Park, about 110 ft (33 m) south of Cub Creek, to about 60 ft (19 m) at Plug Hat Rock 

Forms a narrow ribbon of subdued, easily eroded red rocks and strike valleys 

Low None documented 

Jurassic 

Glen Canyon Sandstone (Navajo/Nugget equivalent  (JTRg) 

Pink to gray- yellow eolian cross- bedded quartz sandstone; thickness 600- 650 ft (180- 200 m) 

Strike ridges, hogbacks, cuestas flanking Split Mt. & Blue Mt. High 

Development on hogbacks will impact viewscape 

Chinle Formation  (TRc) 

Red to gray siltstone, sandstone, and shale with local basal conglomerate (Gartra member); 200-460 ft (60- 140 m) thick 

Garta mbr. forms cliffs, 

benches, caprocks, hogbacks; main body of Chinle forms slopes and narrow strike valleys 

Low: erodes easily except for Garta member Unknown 

Triassic Moenkopi 

Formation  (TRm) 

Mostly red to brown, green, and gray siltstone and shale and fine- grained sandstone; gypsiferous siltstone and shale near base; ripple marks; thickness: 500- 800 ft (150- 240 m) 

Forms floor of many strike valleys and colorful flatirons at Split Mt. gorge 

Low Unknown 

Major Regional Unconformity 

Park City Formation  (Pp) 

Phosphatic marine sandstone, siltstone, dolomite, and limestone with fossils; 100- 430 ft (30- 130 m) thick 

Green and yellow flatirons; forms protective cap on Weber 

Resistant lower ss and cherty limestone; Upper shale, siltstone, limestone, and sandstone more easily eroded 

Development on flatirons will impact viewscape 

Permian Weber 

Sandstone  (Pw) 

Light gray to yellow- gray sandstone with sweeping eolian cross- beds; locally interlayered limestone beds; 650- 1500 ft (200- 470 m) thick. 

Monoliths and cliffs, most notable landforms 

High with well- cemented quartz sandstone 

Development on Weber will impact viewscape 

Pennsylvanian Morgan Formation (PNm) Upper: Red fine- grained sandstone with gray to pale lavender, cherty, fossiliferous marine limestone; thickness 500- 575 ft (150- 175 m) Lower: light- gray to red and green shale and siltstone; 130- 300 ft (40- 90 m) thick Upper: forms red cliffs Lower: forms gray slopes Upper part is resistant; Lower part is easily eroded 

Exposures in Yampa Canyon, Lodore Canyon, and Split Mountain anticline are unsuitable for development 

Rockfalupper punderculower pcollapse 
Age Unit Name (Symbol) Lithology and Description Topographic Expression Erosion Resistance Suitability for Development Ha

Pennsylvanian Round Valley Limestone (PNrv) Light gray to pale lavender, thick- bedded limestone, with thin partings of gray to red shale; pink to red chert; fossiliferous; 200- 300 ft (65- 90 m) thick at Split Mt. and 400 ft (120 m) at the head of Yampa Canyon Forms gray ledgy slopes and/or multi- tiered cliffs High Topographic position makes this formation unsuitable for development Rockfal

collapse 

Doughnut Shale/Humbug Formation  (Mdh) 

Humbug: light- gray to red, fine- to very fine 

grained sandstone interbedded with light- gray limestone and red to black shale. Doughnut: gray shale and gray to red sandstone. 

Combined thickness: 250- 300 ft (75- 90 m) 

Humbug: forms ledgy slopes 

Doughnut: forms slopes 

Humbug Fm is relatively high; Doughnut Shale is relatively low 

Doughnut Shale contains bentonite 

Doughnplastic wprone to 

Mississippian Madison Limestone (Leadville 

equivalent)  (Mm) 

Light- to dark- gray, thick and unevenly bedded, cherty limestone and dolomitic limestone, sparsely fossiliferous; 600- 680 ft (180- 200 m) thick 

Jagged cliffs and dip slopes High 

Dip slopes pose potential development problems 

Karst (s

Precambrian Uinta Mountain Group (Yu) Red fine- to coarse- grained, pebbly, quartzitic sandstone with occasional conglomerate; gray to green and red micaceous shale and siltstone. Thickness: 7000 ft (2100 m), bottom of formation is not exposed; up to 2400 ft (7000 m) thick in adjacent areas Prominent outcrops and cliffs in Canyon of Lodore High Low Rockfal

Major Regional Unconformity 

Cambrian Lodore Formation (Cl) Light brown to green sandstone and shale with basal coarse to pebbly transgressive marine sandstone; thickness: 230- 600 ft (70- 180 m) Ledge- forming sandstone; slope- forming shale Variable Low Rockfal

Major Regional Unconformity 
 DINO Geologic Resource Evaluation Report 17 

Geologic History 

This section highlights the map units (i.e., rocks and unconsolidated deposits) that occur 

in Dinosaur National Monument and puts them in a geologic context in terms of the 

environment in which they were deposited and the timing of geologic events that created 

the present landscape. 

Precambrian 

Continents evolve through a process called accretion 

wherein materials are added to a central continental 

core, known as a craton. By this process a continent 

grows in areal extent through time. Continents may also 

merge and later fragment, resulting in complex histories 

to unravel. 

About 2.5 billion years ago (Archean Eon) in the 

Precambrian, the area that is now Wyoming formed the 

southern margin of the North American craton. 

Sedimentary rocks were deposited and later 

metamorphosed in a broad continental shelf that 

extended to the south and west. As Archean time drew to 

a close, the North American craton experienced a 

growth spurt. Studies of folds and faults in the Red Creek 

Quartzite beneath the overlying Uinta Mountain Group 

indicate that a collisional event began to affect the area 

about 2.3 billion years ago (figure 4) (Hanson, 1975). 

About 1.5 billion years ago a broad, elongate east- west 

trough formed along the southern edge of the Wyoming 

area and filled with the sediments of the Uinta Mountain 

Group, now exposed in Uinta Mountains and in 

Dinosaur National Monument. The trough was probably 

a failed arm of a rifted continental margin (an aulacogen) 

(Gregson and Chure, 2000). Ripple marks, fossil mud 

cracks, and even rain prints suggest that sedimentation 

kept pace with subsidence and that the basin was not 

very deep (Hanson, 1975). Sediments thousands of feet 

thick were deposited, lithified, and then uplifted, tilted 

northeastward, and partially eroded forming the Unita 

Mountian Group (Hansen, 1986b; Gregson and Chure, 

2000). This period of erosion with little or no 

sedimentation created a hiatus (gap) in the stratigraphic 

record that lasted several hundred million years until 

Late Cambrian. The nature of this unconformity is 

described in Hanson (1977). 

Paleozoic Era 

Rare body fossils of trilobites have been found in the 

Cambrian Lodore Formation at Jones Hole (Hanson, 

1996). Sediments and body fossils suggest that the 

Lodore environment was one of warm, shallow marine 

water. 

Another break in sedimentation from the Late Cambrian 

to the Early Mississippian indicates the area must have 

remained relatively high for several million years from 

the Ordovician Period through the Devonian Period. 

While the western margin of North America was 

experiencing accretionary tectonic activity from the 

Antler Orogeny, extensive shallow seas repeatedly 

transgressed and regressed across the Dinosaur area 

depositing the Lower Mississippian Madison Limestone, 

the sandstone, limestone, and shale of the Upper 

Mississippian Humbug Formation, and the dark- gray 

Doughnut Shale. During the Early Mississippian, a 

shallow sea reached from the present day Arctic Ocean 

to the Gulf of Mexico (figure 5). 

Coal in the Doughnut Shale suggests brief intervals of 

non- marine conditions during the Upper Mississippian. 

Fresh or brackish water in vegetation- rich swamps 

mixed with marine environments that led to the 

deposition of coal (Gregson and Chure, 2000). 

Marine environments returned with deposition of the 

Round Valley Limestone of the Lower Pennsylvanian. 

The Round Valley Limestone marks a change in tectonic 

regime. Intermixed with the limestone are nodules of 

pink and red chert. The chert marks the initiation of a 

tectonic event that formed the Ancestral Rocky 

Mountains in Colorado (figure 6). 

Although deformation related to the PennsylvanianPermian Ancestral Rocky Mountain Orogeny has not 

been recognized in the Dinosaur area, the sedimentation 

rates of the late Paleozoic and Mesozoic were greatly 

affected by plate tectonic activity that was suturing South 

America onto the North American continent. Hundreds 

of feet of Middle Pennsylvanian Morgan Formation were 

deposited in beach and near- shore shallow marine 

environments that developed in the Uinta trough. 

Overlying the Morgan Formation is upwards of 470 m 

(1,500 ft) of Middle Pennsylvanian to Lower Permian 

Weber Sandstone. The sweeping cross- beds in the 

Weber indicate that most of the formation was deposited 

in a beach and sand dune environment. Local 

interlayered limestone beds containing marine fossils 

show a close marine association (Gregson and Chure, 

2000). 

A marine environment once again returned to the area 

and is recorded in the Lower Permian Park City 

Formation. Deposits of phosphate- rich sediment 

accumulated as cold, mineral- rich, marine waters welled 

up from the bottom into warmer zones or currents. 

These deposits are now mined for fertilizer in the Brush 

Creek area northwest of Dinosaur NM (Hansen and 

others, 1980, 1983; Maughan, 1979; Rowley, Dyni, and 

others, 1979; Rowley, Kinney, and others, 1979; Rowley 

and others, 1985). 
18 NPS Geologic Resources Division 

Mesozoic Era 

The Lower Triassic Moenkopi Formation rests 

unconformably above the Paleozoic strata. Continental 

environments became more widespread during the 

Mesozoic and dominated the landscape. Near- shore 

continental (possibly tidal flat) environments formed the 

distinctive Moenkopi red beds. Gypsum precipitated in 

times of high aridity. The basal Garta member of the 

Upper Triassic Chinle Formation was deposited in 

streams and rivers possibly in paleovalleys cut into the 

underlying Moenkopi Formation (figure 7). The red to 

gray siltstone, sandstone, and shale that makes up the 

main body of the Chinle represent channel, flood plain 

and lake deposits. 

Eolian environments are recorded in the Lower Jurassic 

Glen Canyon Sandstone and the Middle Jurassic Entrada 

Sandstone. The Glen Canyon Sandstone records an 

extensive sand sea (erg) that covered Utah, Wyoming, 

Colorado, and parts of Arizona and New Mexico. 

Between the Glen Canyon and Entrada Sandstones are 

shallow marine sandy shale, siltstone, sandstone, and 

evaporite deposits of the Middle Jurassic Carmel 

Formation. This formation records the encroachment 

from the north of a shallow sea into the southern 

Wyoming and northern Utah area. Consequently, the 

Entrada erg that formed following retreat of the shallow 

sea, was not as widespread as the Glen Canyon erg. 

Plate activity increased at the end of the Middle Jurassic 

resulting in a major transgression of an inland sea that 

destroyed the vast ergs that once covered the Colorado 

Plateau (Kocurek and Dott, 1983). Marine deposits of the 

Stump Formation record this transgressive event. 

The fluvial and overbank deposits of the Upper Jurassic 

Morrison Formation and the Lower Cretaceous Cedar 

Mountain Formation subsequently buried the Stump 

Formation during a regressive episode. Morrison 

environments were quite varied with sediments 

deposited in mudflats, overbank floodplains, stream 

channels, small eolian sand fields, and scattered lakes 

and ponds (figure 8) (Peterson, 1994). Dinosaur fossils at 

the Dinosaur NM quarry are found in a fluvial 

depositional system within the Salt Wash member of the 

Morrison. Bentonite in the Brushy Basin member of the 

Morrison records volcanic ash falls generated from 

distant volcanoes to the west. Dinosaurs roamed the 

Morrison environments that recent work documents as 

more arid with ephemeral streams than previously 

thought (Turner and Peterson, 1998). 

By Cretaceous time, marine and marginal marine 

environments dominated the area. Crustal loading of the 

east- directed thrust sheets of the Sevier Orogenic thrust 

belt (west of Dinosaur) probably extended the entire 

length of North America creating a continental scale 

foreland basin during the Cretaceous. As the mountains 

rose in the west and the roughly north- south trending 

Western Interior Basin expanded, the Gulf of Mexico 

separating North and South America continued to rift 

open in the south, and marine water advanced 

northward into the basin. At the same time, marine water 

advanced southward onto the continent from the Arctic 

region. As the sea transgressed, shore and near- shore 

sediments accumulated forming the Dakota Sandstone, 

Mowry Shale, and Frontier Sandstone. 

The seas advanced and retreated many times during the 

Cretaceous until the most extensive interior seaway ever 

recorded drowned much of western North America 

(figure 9). The Western Interior Seaway was an elongate 

basin that extended from today’s Gulf of Mexico to the 

Arctic Ocean, a distance of about 4827 km (3,000 mi) 

(Kauffman, 1977). The western margin of the seaway 

coincided with the active Cretaceous Sevier Orogenic 

belt, but the eastern margin was part of a low- lying, 

stable platform ramp in Nebraska and Kansas. The 

marine Mancos Shale and its equivalent to the east, the 

Pierre Shale, were deposited in this sea. Eventually, as the 

western highlands encroached on the western margin of 

the sea, sedimentation increased and multiple cycles of 

coastal bar, beach, lagoon, and swamp deposits 

prograded eastward, filling the seaway. These sediments 

became the formations found in the Mesaverde Group 

and equivalents. 

Cretaceous-Tertiary Laramide Orogeny 

In the Late Cretaceous, basement structures began 

forming in the western foreland basin. These structures 

are the initial structural response to the Laramide 

Orogeny, and as they grew into uplifts and sub- basins, 

the last great seaway of the western interior regressed 

from the continent. The Laramide Orogeny evolved into 

a complex set of thrusted uplifts (highlands) and basins. 

Many of these uplifts, such as the Uinta, Wind River, and 

Sawatch, grew into immense mountain ranges, while 

others formed ridges within the intermontane basins, i.e., 

Douglas Creek, Rock Springs, and Moxa arches. 

The relationship between Laramide deformation and 

thrusting in the Sevier- Wyoming thrust belt to the west 

is not well understood. The Uinta uplift, however, 

overlapped both the Sevier and Laramide events in space 

as well as time so that both events must have influenced 

its development (Gregson and Chure, 200, and 

references therein). With contraction, “the old rift basin 

inverted the subsided structure and uplifted the Uinta 

Mountain Group and underlying Precambrian rocks well 

above much younger strata in the surrounding basins,” 

(Gregson and Chure, 2000, p. 174). Existing structures in 

the foreland were reactivated by Laramide compression 

that also generated multiple new structures. 

Cenozoic Era 

Erosion and sedimentation began almost simultaneously 

as Laramide foreland uplifts became positive features of 

the landscape. Most of the Laramide structures have long 

and complex histories. The Uinta uplift separated the 

greater Green River basin to the north from the Uinta 

Basin to the south. Large lakes filled these basins during 

the Eocene Epoch of the Tertiary Period. Lake Gosiute 

formed north of the arch and Lake Uinta formed to the 

south. The coarse boulders and gravel deposited near the 

mountain front became the Fort Union and Wasatch 

Formations. The finer sand and silt that traveled farther 
 DINO Geologic Resource Evaluation Report 19 

out into the basins became the Wasatch and Green River 

Formations. Fine calcareous and organic- rich muds 

accumulated as thick lakebed deposits and eventually 

became the marlstone and oil shale of the Green River 

Formation. None of these strata, however, are exposed 

in the Dinosaur area. 

Laramide deformation had ceased by Oligocene time. 

Streams had leveled the uplands and mantled the area 

with gravel derived from the crest of the Uinta Range. 

The Bishop Conglomerate (about 29 Ma) blanketed an 

extensive pediment surface known as the Gilbert Peak 

erosion surface. The conglomerate extended up all the 

major valleys and filled in around the high peaks and 

ridges of the Uinta Mountains (Gregson and Chure, 

2000; Hansen and others, 1980, 1983; Hansen, 1986a; 

Rowley, Dyni, and others, 1979; Rowley and others, 

1985). Following the tectonic quiescence of the 

Oligocene, deformation resulted in subsidence and a 

north down, south up rotation of the Uinta range and the 

formation of the Browns Park basin in the Miocene. 

After the Bishop Conglomerate was deposited, the Green 

and Yampa River drainages developed and evolved 

steadily during and after deposition of the Browns Park 

Formation (Gregson and Chure, 2000; Hansen, 1986a). 

The ancestral Yampa River flowed into the easternmost 

Dinosaur area and is responsible for the basal 

conglomerate of the Browns Park Formation. The 

ancestral Green River flowed eastward across the Rock 

Springs uplift in Wyoming. In middle Pleistocene, the 

Green River was captured by the present river drainage 

system. The re- entrenchment of the Green River 

continued after initial canyon development due to 

regional uplift and changes in river discharge. This 

entrenchment of the Green and Yampa Rivers is 

responsible for the spectacular canyons that dominate 

the landscape today. For more detailed information 

about Dinosaur’s Neogene historical geology, please 

refer to Hansen (1986a).
20 NPS Geologic Resources Division 

Figure 4. Precambrian orogenic belts that formed the western part of the North American craton. Ages are in billions of years. Thrust 

faults that sutured the landmasses together are marked by solid triangles with the triangles on the overthrust block of rock. The 

eastern limit of the north-south trending, Mesozoic Sevier thrust belt generally follows the eastern boundary of the Paleozoic passive 

margin and is shown here for reference (westernmost thrust trace). The North American crystalline basement is generally thought to 

extend to the Strontium isotope 0.706 or 0.704 line (dashed line). West of this line, oceanic crust prevails. Modified from Burchfiel and 

others, 1992. 
 DINO Geologic Resource Evaluation Report 21 

Figure 5. Paleogeographic map of the Early Mississippian Period of the western United States. While the lithofacies are complex in the 

foreland basin adjacent to the Antler orogenic highland, a broad carbonate platform spread over eastern Utah, depositing the Madison 

Limestone. Marine water also breached the Transcontinental Arch through the Paleozoic Strait. Any Mississippian rocks that were

deposited on the transcontinental Arch or ancestral Uncompahgre highland during this time have been eroded. Modified from Poole

and Sandberg, 1991. 
22 NPS Geologic Resources Division 

Figure 6. Major uplifts and basins present during the Pennsylvanian Period in the southwestern United States. Sediment eroded from 

the uplifts (gray) was deposited in the adjacent basins (yellow). Both the uplifts and basins resulted from compressional tectonics. 

Note the position of the South American Plate overriding the North American Plate. CCT: Central Colorado Trough. The trough formed 

between the Front Range and Uncompahgre Uplifts. Modified from Rigby, 1977. 

Figure 7. Paleogeographic map of the Late Triassic. UN: Uncompahgre uplift; SL: San Luis uplift; FR: Front Range uplift. Highlands are 

shaded a solid gray. Modified from Dubiel, 1994. 
 DINO Geologic Resource Evaluation Report 23 

Figure 8. Late Jurassic paleogeography. Thin arrows indicate fluvial dispersal. Thick arrows indicate wind directions. Solid triangles 

indicate the location of the subduction zone with the triangles on the overriding, upper lithospheric plate. Note the possible marine 

environment to the east where continental environments were previously established. The alluvial plain expanded to the east with time. 

Modified from Lawton, 1994. 
24 NPS Geologic Resources Division 

Figure 9. Location of the Cretaceous seaway. Shaded areas indicate land above sea level. “S.O.B.” and inverted “V”s indicate the 

Mesozoic Sevier Orogenic belt. North indicates the Cretaceous north. Modified from Rice and Shurr (1983). 
 DINO Geologic Resource Evaluation Report 25 

References 

This section provides a listing of references cited in this report. A more complete geologic 

bibliography is available and can be obtained through the NPS Geologic Resources 

Division. 

Burchfiel, B.C., Cowan, D.S., and Davis, G.A., 1992, 

Tectonic overview of the Cordilleran orogen in the 

western United States, in B.C. Burchfiel, P.W. Lipman, 

and M.L. Zoaback, eds., The Cordilleran Orogen: 

Conterminous U.S.: Geological Society of America, 

The Geology of North America, v. G- 3, p. 407- 480. 

Dubiel, R. F., 1994, Triassic deposystems, 

paleogeography, and paleoclimate of the Western 

Interior, in Mario V. Caputo, James A. Peterson, and 

Karen J. Franczyk, eds., Mesozoic Systems of the 

Rocky Mountain Region, USA: Rocky Mountain 

Section, SEPM (Society for Sedimentary Geology), 

Denver, CO., p. 133- 168. 

Gregson, J. D. and Chure, D. J., 2000, Geology and 

paleontology of Dinosaur National Monument, UtahColorado, in D.A. Sprinkel, T.C. Chidsey, Jr., and P.B. 

Anderson, eds., Geology of Utah’s Parks and 

Monuments: Utah Geological Association Publication 

28, p. 155- 189. 

Hansen, W.R., 1969, The Geologic Story of the Uinta 

Mountains: U.S.G.S. Bulletin 1291, 144 p. 

Hansen, W.R., 1977, Geologic map of the Canyon of 

Lodore South quadrangle, Moffat County, Colorado: 

U.S. Geological Survey Geologic quadrangle Map GQ1403, scale 1:24,000. 

Hansen, W.R., 1986a, Neogene tectonics and 

geomorphology of the eastern Uinta Mountains in 

Utah, Colorado, and Wyoming: U.S. Geological Survey 

Professional Paper 1356, 78 p. 

Hansen, W.R., 1986b, History of faulting in the eastern 

Uinta Mountains, Colorado and Utah, in Stone, D.S., 

ed., New Interpretations of Northwest Colorado 

Geology: Rocky Mountain Association of Geologists, 

p. 229- 246. 

Hansen, W.R., 1996, Dinosaur’s restless rivers and craggy 

canyon walls: Vernal, Dinosaur Nature Association, 

103 p. 

Hansen, W.R., Carrara, P.E., and Rowley, P.D., 1980, 

Geologic map of the Haystack Rock quadrangle, 

Moffat County, Colorado: U.S. Geological Survey 

Geologic Quadrangle Map GQ- 1535, scale 1:24,000. 

Hansen, W.R., Rowley, P.D., and Carrara, P.E., 1983, 

Geologic map of Dinosaur National Monument and 

vicinity, Utah and Colorado: W.S. Geological Survey 

Miscellaneous Investigations Series Map I- 1407, scale 

1:50,000. 

Kauffman, E. G., 1977, Geological and biological 

overview: Western Interior Cretaceous Basin: 

Mountain Geologist, v. 14, p. 75- 99. 

Kiver, E.P., and Harris, D.V., 1999, Geology of U.S. 

Parklands: John Wiley & Sons, Inc., New York, p. 601-

613. 

Kocurek, G. and Dott, R. H. Jr., 1983, Jurassic 

paleogeography and paleoclimate of the central and 

southern Rocky Mountain region, in Mitchell W. 

Reynolds and Edward D. Dolly, eds., Mesozoic 

Paleogeography of the West- Central United States: 

Rocky Mountain Section, SEPM (Society for 

Sedimentary Geology), Denver, CO., p. 101- 118. 

Lawton, T. F., 1994, Tectonic setting of Mesozoic 

sedimentary basins, Rocky Mountain region, United 

States, in Mario V. Caputo, James A. Peterson, and 

Karen J. Franczyk, eds., Mesozoic Systems of the 

Rocky Mountain Region, USA: Rocky Mountain 

Section, SEPM (Society for Sedimentary Geology), 

Denver, CO., p. 1- 26. 

Maughan, E.K., 1979, Petroleum source rock evaluation 

of the Permian Park City Group in the northeastern 

Great Basin, Utah, Nevada, and Idaho, in Newman, 

G.W. and Goode, H.D., eds., basin and Range 

Symposium: Rocky Mountain Association of 

Geologists – Utah Geological Association, p. 523- 530. 

McIntosh, J.S., 1977, Dinosaur National Monument: 

Constellation Press, Phoenix, 40 p. 

Mussetter,R.A., and Harvey, M.D., 1999, Geologic and 

geomorphic associations with Colorado pikeminnow 

spawning, lower Yampa River, Colorado, in 1999 

Geological Society of America Annual Meeting , 

Abstracts with Programs, v.31, no.7, p. 483. 

Peterson, F., 1994, Sand dunes, sabkhas, stream, and 

shallow seas: Jurassic paleogeography in the southern 

part of the Western Interior Basin, in Mario V. Caputo, 

James A. Peterson, and Karen J. Franczyk, eds., 

Mesozoic Systems of the Rocky Mountain Region, 

USA: Rocky Mountain Section, SEPM (Society for 

Sedimentary Geology), Denver, CO., p. 233- 272. 
26 NPS Geologic Resources Division 

Poole, F. G. and Sandberg, C. A., 1991, Mississippian 

paleogeography and conodont biostratigraphy of the 

western United States, in John D. Cooper and Calvin 

H. Stevens, eds., Paleozoic Paleogeography of the 

Western United States – II: Society of Economic 

Paleontologists and Mineralogists (SEPM), Pacific 

Section, p. 107- 136. 

Rigby, J. K., 1977, Southern Colorado Plateau: Kendall/ 

Hunt Publishing Company, Dubuque, IA., 148 p. 

Rice, D. D. and Shurr, G. W., 1983, Patterns of 

sedimentation and paleogeography across the Western 

Interior Seaway during time of deposition of Upper 

Cretaceous Eagle Sandstone and equivalent rocks, 

northern Great Plains, in Mitchell W. Reynolds and 

Edward D. Dolly, eds., Mesozoic Paleogeography of 

the West- Central United States: Rocky Mountain 

Section, SEPM (Society for Sedimentary Geology), p. 

337- 358. 

Rowley, P.D., Dyni, J.R., Hansen, W.R., and Pipiringos, 

G.N., 1979, Geologic map of the Indian Water Canyon 

quadrangle, Moffat County, Colorado: U.S. Geological 

Survey Geologic Quadrangle Map GQ- 1516, scale 1: 

24,000. 

Rowley, P.D., Hansen, W.R., Tweto, O., and Carrara, 

P.E., 1985, Geologic map of the Vernal 1o

 X 2o

quadrangle, Colorado, Utah, and Wyoming: U.S. 

Geological Survey Map Miscellaneous Investigations 

Series I- 1526, scale 1:250,000. 

Rowley, P.D., Kinney, D.M., and Hansen, W.R., 1979, 

Geologic map of the Dinosaur Quarry quadrangle, 

Uintah County, Utah: U.S. Geologic Survey Geologic 

Quadrangle Map GQ- 1513, scale 1:24,000. 

Santucci, V.L., 2000, A survey of paleontologic resources 

from the National Parks and Monument sin Utah, in 

D.A. Sprinkel, T.C. Chidsey, Jr., and P.B. Anderson, 

eds., Geology of Utah’s Parks and Monuments: Utah 

Geological Association Publication 28, p. 535- 556. 

Turner, C.E., and Peterson, F., 1998, The Morrison 

Formation extinct ecosystems project – final report: 

National Park Service/U.S. Geological Survey 

Interagency Agreement No. 1443- IA- 1200- 94- 003, 

594 p. 

Untermann, G.E., and Untermann, B.R., 1969, A popular 

guide to the geology of Dinosaur National Monument: 

Dinosaur Nature Association, Jensen, 126 p.
 DINO Geologic Resource Evaluation Report 27 

Appendix A: Geologic Map Graphic 

The following page provides a preview or “snapshot” of the geologic map for Dinosaur 

National Monument. For a poster size PDF of this map or for digital geologic map data, 

please see the included CD or visit the GRE publications webpage: 

http://www2.nature.nps.gov/geology/inventory/gre_publications.cfm 

 DINO Geologic Resource Evaluation Report 29 

Appendix B: Scoping Summary 

The following excerpts are from the GRE scoping summary for Dinosaur National 

Monument. The scoping meeting occurred August 10- 11, 1998; therefore, the contact 

information and Web addresses referred to herein may be outdated. Please contact to 

the Geologic Resources Division for current information. 

Workshop Summary 

An inventory workshop was held at Dinosaur National 

Monument on August 10- 11, 1998 to discuss the 

monument’s geologic resources and associated issues 

and needs. In all, fifteen cooperators participated in the 

two- day workshop. The list of participants can be found 

at the end of this section. 

Field Trip 

In the morning of the first day of the workshop, Wallace 

Hansen, who mapped most of the Dinosaur area before 

retiring from the USGS, led a field trip for many of the 

cooperators. The group traveled to Harpers Corner to 

discuss the stratigraphy, structure, and geomorphology 

of the monument. Along the Harpers Corner road, the 

group stopped to discuss areas of unstable roadway due 

to slumps and landslides. 

In the afternoon, the field trip visited the Green River 

District of the monument. The Dinosaur NM Chief of 

Maintenance, explained stabilization work that will be 

done along the bank of the Green River near the park 

entrance, where the river has been actively eroding its cut 

bank into the road base that was constructed in the 

Mancos Shale slope. At Cub Creek, where the road 

crosses the stream, the group discussed the historic 

channel incision and recent high flows and 

sedimentation that create numerous problems for road 

maintenance. The trip ended with a hike from Josey 

Morris Ranch to Hog Canyon to view and discuss a 

stream restoration project that was done to benefit the 

Ute Ladies- Tresses Orchid, a federally listed rare plant. 

Steve Petersburg explained that the restoration project 

has raised the local water table in Hog Canyon, which is a 

relatively short box canyon eroded into the Weber 

Sandstone. The increased height of the water table and 

exclosure of cattle has allowed for recovery and thick 

riparian growth of vegetation on the canyon floor, but 

has given limited results for increasing the population of 

the rare orchid, which appears to grow best on 

periodically disturbed areas. 

Workshop Meeting 

After introductions by the participants, Bill Dye and Gary 

Mott of Dinosaur NM maintenance took the group on a 

tour of the Dinosaur Quarry Visitor Center to show the 

extent of the damage caused by movement of the 

substrate beneath the building. Issues with the visitor 

center building are discussed in more detail in the 

Hazards section. 

Joe Gregson, I&M geologist/information manager, 

presented an overview of the NPS I&M Program, the 

status of the natural resource inventories, and the 

geological resources inventory. Bruce Heise, NPS GRD 

geologist, followed with an overview of the organization 

of the Natural Resource Stewardship and Science 

Washington Office, GRD, and the Colorado pilot 

project. 

Dan Chure, park paleontologist, gave the group a tour of 

the Jurassic quarry and discussed the instability of the 

exposed Morrison Formation and fossils. Dan also took 

the group just east of the Quarry Visitor Center to show 

and discuss unstable mass wasting conditions associated 

with the historic quarry office that had been constructed 

by Earl Douglas. 

Christine Turner and Fred Peterson, USGS geologists, 

gave an overview and discussed important results of the 

Morrison Initiative, which was an intensive, 

multidisciplinary research project that comprehensively 

studied the Morrison Formation associated with 

paleontological sites throughout the west. Much of the 

Morrison Initiative work was done in NPS units, and 

Dan Chure played a key role in its success. 

After lunch, Ann Elder and Scott Madsen, park museum 

specialists/paleontologists, gave the group a tour of a new 

dinosaur quarry site (2 Sauropods) located west of the 

Quarry Visitor Center in the Lower Cretaceous Cedar 

Mountain Formation that is an important faunal locality 

for this time period. 

Tamara Naumann, park botanist, discussed the 

association of rare plants with certain geologic strata and 

geomorphic surfaces. Tamara shared issues about the 

Ute Ladies- Tresses Orchid, a federally listed threatened 

plant that occurs in the monument with significant 

populations in Lodore Canyon. 

The remainder of the meeting was devoted to discussing 

the status of geologic and paleontologic mapping at 

Dinosaur as well as resources that could contribute to a 

geologic report about the monument. 

Hazards 

Several hazards were discussed that affect the 

monument- - especially the maintenance of park roads 

and buildings. Most of the hazards were associated with 

slope or substrate instability and mass wasting events. 
30 NPS Geologic Resources Division 

1. Along the Harpers Corner road, slumps in existing 

landslide materials (mostly derived from the Jurassic 

Morrison Formation) create maintenance and traffic 

hazards in several areas. Dinosaur NM Maintenance is 

considering relocating the roadways to the crests of 

associated ridges to help alleviate the slumping 

problems. 

2. Along the quarry entrance road near the park 

boundary, the Green River has been actively eroding 

its cutbank into the road base that was constructed 

into the Mancos Shale slope. Dinosaur NM 

maintenance has a project in work that will fill in the 

eroded areas and armor the bank with riprap to 

protect the road for a time. The hazardous location of 

the road, unstable Mancos badlands above, and Green 

River erosion below, were discussed. The only 

permanent solution may be to move the road to the 

opposite bank of the Green River, which has its own 

set of engineering and political issues. 

3. At Cub Creek where the road crosses the stream, the 

creek has incised several meters into the older valley 

fill deposits. Upstream of the road crossing, recent 

beaver dams may be restoring the riparian zone and 

arresting the entrenchment, but this spring, high 

stream flow eroded around the end of a beaver dam 

and directed the stream against the road embankment. 

Dinosaur NM maintenance had to breach the beaver 

dam to get the stream flowing back into its main 

channel and through the culvert under the road. 

Subsequently, Dinosaur NM maintenance placed 

riprap to armor the upstream portion of the roadbed, 

but the stream rapidly silted in upstream of the barrier, 

indicating that although entrenched, the stream is still 

moving significant sediment. This problematic area 

could benefit from a comprehensive study of the 

hydrology and geomorphology with the goal of 

restoring the pre- entrenchment channel geometry and 

fluvial regime. 

4. The relocation of the Echo Park campground was 

discussed. The existing campground is located on the 

cutbank of the Green River just below its confluence 

with the Yampa River in the bend of the river around 

Steamboat Rock. Dinosaur NM maintenance 

personnel indicated that tentative plans were to 

relocate the campground back from the river on the 

west side of the Pool Creek canyon to take advantage 

of the tree cover. It was noted that the close proximity 

of a side canyon and Pool Creek to west side area has a 

greater risk for flash floods and debris flows than 

would a location on the east side of the creek and 

canyon (where, unfortunately, there is no tree cover). 

5. The Quarry Visitor Center has undergone major 

damage due to expanding, contracting, and shifting 

substrate beneath the building. Although the quarry 

face appears to be somewhat stable, the central part of 

the structure appears to be sinking and significant 

offsets of several inches to a foot or more are readily 

apparent in many areas of the building. The obvious 

floor deformation and tilting of support beams and 

windows suggest that the structural integrity of the 

building may be in jeopardy. The site location is on the 

Morrison Formation, which dips about 50 degrees 

toward the south. The Morrison contains abundant 

smectitic clays called bentonite, which swell and 

contract greatly with changes in fluid content. 

Dinosaur NM maintenance has isolated plumbing in 

the building and kept the roof in good condition to 

limit the amount of water that can infiltrate under the 

building, but the deformation continues. Also, 

Dinosaur NM maintenance has reinforced the spiral 

walkway but must also continually monitor the 

freestanding structure for movement. Deformation 

and ground movement are also readily apparent in the 

parking lot and sidewalk outside of the building. 

Dinosaur NM maintenance has received some 

engineering review from the Denver Service Center, 

but a comprehensive engineering study has never been 

undertaken. The quarry building is considered a 

historic structure, so approval must be obtained for 

any architectural modifications. Dinosaur staff 

expressed the need for major reconstruction of the 

quarry building, and all of the cooperators concurred. 

Although building renovation is well outside the scope 

of the geologic resources inventory, it is recommended 

that the ongoing deformation of the quarry building 

and surrounding area should be studied and that a 

major engineering review to address the structural 

problems is needed. 

6. Without discussing the details, Dinosaur staff noted 

that similar, but less severe, foundation- movement 

issues exist at the headquarters building. 

7. Although not specifically discussed, a geologic hazards 

map is needed for park planning and maintenance. 

Research Needs 

1. Tamara Naumann, Dinosaur NM botanist, discussed 

the association of rare plants with certain geologic 

strata and geomorphic surfaces. The Uinta Basin has 

30- 40 endemic plant species of which 15- 20 occur 

within Dinosaur NM. Tamara shared issues about the 

Ute Ladies- Tresses Orchid, a federally listed 

threatened plant that occurs in the monument with 

significant populations in Lodore Canyon. In the 

canyon, the rare orchids grow somewhat abundantly 

and show a strong correlation with geomorphic 

surfaces formed under the flow regime established by 

discharge from the Flaming Gorge dam. J.C. Schmidt 

and Paul Grams (who mapped the geomorphic 

surfaces in Dinosaurs canyons) of Utah State 

University assisted with the orchid inventory. A 

significant issue is that increased flows from Flaming 

Gorge have been proposed to assist the recovery of 

endangered fish in the Green River, but the increased 

flows might endanger the new- found orchid 

population. Analysis of existing data is in progress, and 

further research is needed to determine the effect of 

flooding on the existing surfaces and plants, as well as, 

how and if higher flows might create new habitat for 

the orchid in areas such as Brown’s Park. The research 
 DINO Geologic Resource Evaluation Report 31 

will assist with the preparation of a mitigation plan that 

could help both the orchids and fish. 

2. During the discussion of the Morrison Initiative and 

while visiting the Lower Cretaceous dinosaur dig, it 

was noted that a comprehensive, multidisciplinary 

study of the Cedar Mountain and correlative 

formations would give significant understanding of the 

paleoenvironments of that time period. New research 

might include detailed sedimentology, stratigraphy, 

palynology, pedology, as well as invertebrate and floral 

paleontology. Understanding of the new quarry site in 

the Cedar Mountain Formation and its fossils would 

be greatly enhanced by such a study. 

3. Although the present quarry preparation facilities are 

quite good, several problems exist for long- term 

preparation and curation of specimens. The present 

facility is located in the Quarry Visitor Center with its 

structural building problems discussed earlier. In 

addition, specimen storage facilities are inadequate for 

the ever- growing collection. Working collections are 

stored at the quarry site, but others are stored in sheds 

or the basement of the headquarters building more 

than 20 miles away. Improperly ventilated storage 

facilities make working with radioactive specimens 

(that contribute to the buildup of radon gas) a 

hazardous task. Dinosaur NM staff proposed that a 

new building should be constructed at another, more 

stable site. The new building would provide 

infrastructure for collection preparation and curation, 

scientific research, resource management, as well as 

inventory and monitoring activities—all under one 

roof. 

4. As mentioned above, a study of the hydrology and 

geomorphology of Cub Creek in conjunction with 

planning for a stream restoration project would assist 

with continual road maintenance problems in that 

area. 

5. Wallace Hansen suggested that two very large juniper 

trees in Yampa Canyon, that may be record trees 

measuring 144” and 120” in circumference, should be 

cored to get their age and a climate record. Trees of 

this size may be 2000 or more years old. Tamara 

Naumann agreed to do the project. Wallace also 

suggested that vandalized rock art could be retouched, 

and the group concurred. 

Interpretation 

Although specific interpretive issues were not discussed 

in detail, several resources associated with geology 

were noted. 

1. Christine Turner and Fred Peterson of the USGS are 

working with other researchers on a comprehensive 

report for the Morrison Initiative. They think that after 

completion of the comprehensive scientific report that 

a summary report of the important results will be 

written for Dinosaur NM and the general public. 

2. Christine Turner and Fred Peterson also discussed 

earlier work for a professional society geologic 

guidebook and road log that linked Permian 

formations among various parks and other sites for the 

Colorado Plateau. Geologic guidebook road logs have 

also been discussed at other workshops as an 

overarching interpretive theme among parks. 

3. Several interpretive publications related to geology are 

available for Dinosaur NM. A comprehensive geologic 

map of Dinosaur NM has been compiled and 

published (Hansen, Rowley, and Carrara, 1983) and is 

for sale in the monument bookstores. A river runner’s 

guide (Hansen, 1993), that is published by the Dinosaur 

Nature Association and that explains the general 

geology of the monument quite well, is also for sale. A 

USGS Professional Paper and Rocky Mountain 

Association of Geologists paper about the Eastern 

Uinta Mountains (both by Hansen, 1986) are available 

but not for sale. Other resources by the Untermanns 

and Don Stone are also available but not sold in the 

bookstores. A generalized geology publication for 

Dinosaur NM would make a useful interpretive 

addition to the existing publications. 

Maps 

1. Geologic Maps. Due to the extensive work by Wallace 

Hansen and his colleagues, the geology of the 

Dinosaur area has been well mapped. Fifteen 1:24,000 

and several smaller scale maps, including a 1:50,000 

scale Dinosaur National Monument map (Hansen, 

Rowley, and Carrara, 1983), exist for the area. At the 

subsequent map evaluation meeting at the USGS in 

Denver, stable- base source maps will be sought for 

developing a digital geologic coverage for the park. 

Several in the group had heard about the existence of 

scanned versions of the Dinosaur NM maps, but no 

one knew of their status. Michele Gudorf of the 

Intermountain Region GIS group was contacted, and 

only part of the existing map coverage is available and 

that is probably in an old version of GRASS GIS and 

will not be useable for the inventory map products. 

Michele is sending a copy of the data to the I&M 

Program in Fort Collins for evaluation. 

2. Paleontologic Maps. Dan Chure discussed the fact that 

no complete maps showing the locations of the quarry 

sites and fossil locations currently exist. Source maps 

of the Carnegie, Smithsonian, and University of Utah 

quarry activities are available, and a National Science 

Foundation grant has been acquired to compile a 

comprehensive map and database of the fossil 

attributes and locations. A contractor(?) in Salt Lake 

City is compiling the map and database of more than 

4000 records that document more than 400 fossil 

animals. A multimedia demonstration project is also in 

work that will combine photos, drawings, literature, 

citations, etc. into an interactive visitor display. The 

Carnegie Museum wants to publish the completed 

map for sale. 

3. GIS Data. The cooperators discussed that some GIS 

data had been developed for the monument and that 

other base cartographic data should be available from 

the I&M Program, the Intermountain Region GIS staff, 
32 NPS Geologic Resources Division 

and Moffat County (DOQQs). The I&M Program has 

DLG, DEM, DRG, and DOQ data available on CDROM, so Moffat will not be contacted. The 

Intermountain Region GIS staff has the partial geologic 

raster map(s) and a coarse vegetation coverage 

available. The geomorphic surfaces coverage may be 

available from Paul Grams of Utah State University. 

4. GIS Needs. Dinosaur NM does not currently have an 

operational GIS. Since Dinosaur does not have a FTE 

to dedicate for a GIS Specialist position, the best 

alternative is to acquire a desktop GIS system (i.e., 

Arcview GIS) that the scientific and resource 

management staff could use to support their research, 

inventory, and monitoring activities. The I&M and 

Intermountain Region GIS Programs should be able to 

assist Dinosaur NM staff with setting up a GIS system 

for the park. 

Report 

Several geologic reports already exist that cover the 

Dinosaur area quite well as discussed in 3 under 

Interpretation above. The consensus of the group was 

that a synopsis of the existing material could be compiled 

for the geologic inventory report. Paleontology (Dan 

Chure), hazards, data, and other sections will be 

compiled and written by GRD and I&M staff as needed. 

ACTION ITEMS 

1. Joe Gregson will check for available digital base 

cartographic and other GIS data that is available for 

Dinosaur NM (DONE, 9/18/98). 

2. Obtain stable- base geologic map masters from USGS 

for digitizing. 

3. Digitize, attribute, and develop GIS for Dinosaur NM 

geologic maps. 

4. Compile, edit, and distribute a Dinosaur NM geologic 

report. 

5. Establish a GIS system for Dinosaur NM (I&M and 

IMR will assist with data). Dinosaur NM staff should 

propose an Arcview GIS system for funding by the 

IMR GIS FTSC (Teresa Ely). (**Need to identify at 

least one Dinosaur NM NR staffer to take the lead for 

this desktop GIS.) 

6. Geologic hazards map. Check with states of Colorado 

and Utah for any existing data. Assess feasibility of 

developing hazards map for park GIS. 

7. Abandoned mine lands inventory. Review topographic 

maps for locations of mine adits and shafts. Develop 

GIS coverage and AML data records if possible. 

8. Develop paleontological themes for park GIS 

(DINO/USGS/IMR projects). 

9. Archive Dinosaur NM research library materials into 

NRBIB Procite database. Vince Santucci has contacted 

Scott Palowski, archivist at Yellowstone N.P. about a 

detail to assist with this project. 

10. Conduct a cave inventory (unique geologic features). 

Inverviews with Dinosaur NM staff provided 

information about several caves in the monument. 

Identified caves include Whispering, Signature, 

Mantell, Interstate, and Cave of Logs. Copies of 

reports were forwarded to Ron Kerbo of NPS GRD.

Workship Cooperators 

Dan Chure, Dinosaur NM Park Paleontologist 

Ann Elder, Dinosaur NM Museum SpecialistPaleontologist 

Scott Madsen, Dinosaur NM Museum SpecialistPaleontologist 

Tamarra Naumann, Dinosaur NM Botanist 

Steve Petersburg, Dinosaur NM Resource Management 

Bill Dye, Dinosaur NM Maintenance 

Gary Mott, Dinosaur NM Maintenance 

Joe Gregson, NPS I&M Program 

Bruce Heise, NPS GRD 

Vince Santucci, NPS GRD – FOBU 

Tim Connors, NPS GRD 

Wallace Hansen, USGS (retired) 

Christine Turner, USGS Denver 

Fred Peterson, USGS Denver (GIP) 
The Department of the Interior protects and manages the nation’s natural resources and cultural heritage; provides scientific and other information about 

those resources; and honors its special responsibilities to American Indians, Alaska Natives, and affiliated Island Communities. 

Dinosaur National Monument 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2006/008 

NPS D-217, March 2006 

National Park Service 

Director • Fran P. Mainella 

Natural Resource Stewardship and Science 

Associate Director • Michael A. Soukup 

Natural Resource Program Center 

The Natural Resource Program Center (NRPC) is the core of the NPS Natural Resource Stewardship and Science 

Directorate. The Center Director is located in Fort Collins, with staff located principally in Lakewood and Fort 

Collins, Colorado and in Washington, D.C. The NRPC has five divisions: Air Resources Division, Biological 

Resource Management Division, Environmental Quality Division, Geologic Resources Division, and Water 

Resources Division. NRPC also includes three offices: The Office of Education and Outreach, the Office of 

Inventory, Monitoring and Evaluation, and the Office of Natural Resource Information Systems. In addition, Natural 

Resource Web Management and Partnership Coordination are cross-cutting disciplines under the Center Director. The 

multidisciplinary staff of NRPC is dedicated to resolving park resource management challenges originating in and 

outside units of the national park system. 

Geologic Resources Division 

Chief • David B. Shaver 

Planning Evaluation and Permits Branch Chief • Carol McCoy 

Credits 

Author • Dr. John Graham

Editing • Sid Covington, and Bruce Heise 

Digital Map Production • Stephanie O’Meara, Jenny Adams, Jerome Walker, Abbey Abbley, and Eileen Ernenwein 

Map Layout Design • Melanie Ransmeier 
Geologic Resources Division 

Natural Resource Program Center 

P.O. Box 25287 

Denver, CO 80225 

http://www.nature.nps.gov/geology/inventory/ 

(303) 969-2090 

EXPERIENCE YOUR AMERICATM 

National Park Service 

U.S. Department of the Interior