Colorado National Monument 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2006/007 

National Park Service 

U.S. Department of the Interior 

Natural Resource Program Center 
THIS PAGE: 

Independence Monument , Colorado NM. 

Photos by: NPS 
Colorado National Monument 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2006/007 

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 

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general, diverse audience, and may contain NPS policy considerations or address sensitive 

issues of management applicability. Examples of the diverse array of reports published in this 

series include vital signs monitoring plans; "how to" resource management papers; 

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

only available as long as the supply lasts. This report is also available from the Geologic 

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gre_publications) on the internet, or by sending a request to the address on the back cover. 

Please cite this publication as: 

KellerLynn, K. 2006. Colorado National Monument Geologic Resource Evaluation Report. 

Natural Resource Report NPS/NRPC/GRD/NRR—2006/007. National Park Service, Denver, 

Colorado. 

NPS D-86, March 2006 
 COLM 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

Geologic Setting .........................................................................................................................................................3

Geologic Issues............................................................................................................. 5

Abandoned Mine Lands..............................................................................................................................................5

Biological and Physical Soil Crusts.............................................................................................................................5

Erosion .......................................................................................................................................................................6

Expansive Soils and Clays .........................................................................................................................................6

Flash Floods...............................................................................................................................................................6

Groundwater Level and Quality ..................................................................................................................................7

Hydrocompaction........................................................................................................................................................7

Mineral Resources......................................................................................................................................................7

Outdoor Classroom ....................................................................................................................................................7

Paleontological Resources .........................................................................................................................................8

Seismicity and Eolian Sediments................................................................................................................................8

Slope Failure ..............................................................................................................................................................9

Urban Development....................................................................................................................................................9

Wetlands ..................................................................................................................................................................10

Geologic Features and Processes............................................................................. 14

Alluvial Fans .............................................................................................................................................................14

Eolian Processes......................................................................................................................................................14

Erosional Features ...................................................................................................................................................14

Flash Floods.............................................................................................................................................................14

Hydrogeology ...........................................................................................................................................................15

Late Cenozoic Uplift .................................................................................................................................................15

Paleontology and Fossils..........................................................................................................................................16

Tectonic Structures...................................................................................................................................................17

Unconformities..........................................................................................................................................................17

Valley-Fill Deposits...................................................................................................................................................17

Map Unit Properties .................................................................................................... 19

Map Unit Properties Table........................................................................................................................................20

Geologic History.......................................................................................................... 23

References Cited......................................................................................................... 26

Appendix A: Geologic Map Graphic .......................................................................... 29

Appendix B: Scoping Summary................................................................................. 31

Appendix C: Geoindicators Report............................................................................ 33 

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

List of Figures 

Figure 1. Physiographic Provinces of the Conterminous United States. ........................................................................2 

Figure 2. Polyurethane foam used for mitigating hazardous mine openings................................................................11 

Figure 3. Bat in Kodel Gold Mine. ................................................................................................................................11 

Figure 4. Flash Flood Deposit.. ....................................................................................................................................12 

Figure 5. Monocline......................................................................................................................................................13 

Figure 6. Rockfall Area.................................................................................................................................................13 

Figure 7. Map of Colorado National Monument. ..........................................................................................................24 

Figure 8. Geologic Time Scale.....................................................................................................................................24 
 COLM Geologic Resource Evaluation Report 1

Executive Summary 

This report has been developed to accompany the digital geologic map of Colorado National 

Monument, which was produced by Geologic Resource Evaluation staff. It contains 

information relevant to resource management and scientific research. 

The brightly colored cliff- walled canyons and towering 

monoliths of Colorado National Monument are part of 

the canyonlands region of the Colorado Plateau province 

that stretches hundreds of miles to the west and south of 

the monument. The eastern margin of the monument 

and the Uncompahgre Plateau is marked by a great 

monocline—a textbook example of a Laramide structure. 

Many such spectacular geologic structures extend for 

miles across the Colorado Plateau of Colorado, Utah, 

Arizona, and New Mexico (fig. 1). The uppermost 

sedimentary strata that cap the plateau bend across the 

monoclinal hinge line and plunge nearly 2,000 feet (610 

m) to the valley below. These strata display an 

exceptional record of Mesozoic rocks. Wind, water, and 

frost action have carved the variegated sedimentary 

rocks into pinnacles and massive rock spires that rise 

from the floors of the canyons. Scoured rocks “balance” 

atop tall columns of sandstone. Erosion has formed 

natural bridges and arches, and shear- walled canyons. 

Colorado National Monuments is one of the only places 

on the Colorado Plateau to view Precambrian rocks. 

Exposed on the floors of the canyons, Triassic rocks 

overlie the ancient basement, marking an unconformity 

in the geologic record of about 1.17 billion years. 

Geologic processes that began millions of years ago are 

ongoing today. Recognition of these active processes will 

aid the park in planning for rapid urban development 

near and up to the boundary of the park, as well as 

planning for an expected increase in visitation as a result 

of local population growth. Planning and resource 

management benefit from an awareness of geologic 

features and processes when working to preserve or 

restore them as appropriate. Some of the geologically 

significant issues for Colorado National Monument are: 

• Flash Floods—Flash floods are one of the principal 

agents that form and modify the landscape of the 

monument. They are natural process that is of concern 

to homeowners at the mouths of the canyons just 

outside the park boundary. Because the park is often 

held responsible for the destruction property near the 

park boundary, it behooves park staff to educate local 

residents about the long history of flash flooding in the 

area and help them to make informed decisions with 

respect to the location of their homes. 

• Slope Failure—Slope failure happens continuously 

throughout the park and is a constant maintenance 

issue along Rim Rock Drive. Slope failure is a concern 

for park management, particularly with respect to 

potential road failure. In addition, rockfalls are also a 

concern for visitor safety, especially along Rim Rock 

Drive and at overlooks. 

• Erosion—The process of erosion, which created many 

of the landforms of Colorado National Monument, is a 

fundamental natural process that has been operating 

for millions of years. The present- day ecosystem was 

developed through the process of erosion. However, 

erosion may also expose paleontological resources 

increasing the potential for fossil theft and vandalism. 

• Groundwater—Decrease in groundwater level could 

have a direct effect on seeps and springs in the 

monument and the plants and animals that depend on 

them. In addition, a decrease in groundwater could 

affect wetlands in the monument. Quantifying 

groundwater levels is important for management 

planning and future decision making as it relates to 

development outside of the monument boundary. 

• Soil Crusts—Biological and physical soil crusts are a 

distinctive and fragile resource that require protection 

because they protect underlying fine material from 

wind erosion; fix atmospheric nitrogen vascular plants; 

provide carbon to the interspaces between vegetation; 

secrete metals that stimulate plant growth; capture 

dust (i.e., nutrients) on their rough, wet surfaces; and 

decrease surface albedo. Also, depending on soil 

characteristics, biological crusts may either increase or 

reduce rates of water infiltration; by increasing surface 

roughness. Biological and physical soil crusts often 

reduce runoff, thus increasing infiltration and the 

amount of water stored for plant use. 

• Wetlands—The scarcity of wetlands increases their 

importance to plants and wildlife as a source of water. 

Wetlands provide cooler temperatures and greater 

plant and animal diversity. These areas are sites of 

hanging gardens that provide habitat for threatened 

and endangered species. A significant human influence 

on wetlands in the monument has been the Fruita 

pipeline, which leaked and created artificial habitats 

ideal for exotic plants. Additionally, two reservoirs 

were constructed to provide water to the citizens of 

Fruita. These are no longer in use, but future demand 

could cause them to be restored. 

• Sand and Gravel Resources—Sand and gravel 

resources are abundant in the vicinity of Colorado 

National Monument (Scott and others, 2001a). These 

resources have been and are being developed in the 

Grand Valley to the north. Since sand and gravel are 

used for road maintenance in the park and for a variety 

of other needs, an awareness of nearby sources outside 

the park is important. As Grand Junction continues to 

grow, the demand for sand and gravel is increasing and 

availability is becoming more scarce in the vicinity of 

the monument. 
 NPS Geologic Resources Division 2 

Figure 1. Physiographic Provinces of the Conterminous United States. Colorado National Monument is part of the Colorado Plateau

physiographic province—an eroded desert landscape that covers parts of Colorado, Utah, Arizona, and New Mexico. Colorado National 

Monument stands as the province’s most visible beginnings on the western Grand Junction skyline. 
 COLM 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 features and processes serve as the foundation 

of park ecosystems and an understanding of geologic 

resources yields 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. Ultimately, the 

inventory and monitoring of natural resources will 

become integral parts of park planning, operations and 

maintenance, visitor protection, and interpretation. 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 27o 

“Natural Area” parks with a digital geologic map, a 

geologic resource evaluation report, and a geologic 

bibliography. Each product is a tool to support the 

stewardship of park resources and 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 specific geologic issues affecting the park. During 

these meetings park staff are afforded the opportunity to 

meet with experts on the geology of the park. Scoping 

meetings are usually held at each park, which permits a 

focused discussion and exploration of available 

information on a park’s resources. However, some 

scoping meetings have involved multiple parks or an 

entire Vital Signs Monitoring Network to expedite the 

inventory process. 

Geologic Setting 

The Colorado Plateau and its eroded desert landscape 

covers parts of Colorado, Utah, Arizona, and New 

Mexico, including the canyonlands of Utah and the 

Grand Canyon in Arizona (figure 1). Heading west, this 

spectacular region has its most visible beginnings on the 

western Grand Junction skyline in Colorado National 

Monument (Carpenter, 2002). 

Geologic processes have been creating the features of 

Colorado National Monument for nearly 2 billion years. 

These processes include volcanism in island arcs along 

the growing ancestral North American continental 

margin, high- grade metamorphism, several periods of 

mountain building and deep erosion, deposition of 

marine and non- marine sediments, more uplift, and 

finally erosion that carved the present- day landforms. 

Colorado National Monument lies along the 

northeastern flank of a large topographic feature known 

as the Uncompahgre Plateau—a high, relatively flat, 

elongated region that extends from Ridgeway, Colorado, 

northwestward to near Cisco, Utah. Metamorphosed 

crystalline rocks (1.7 billion years old) seen in the 

monument underlie the entire length of the plateau. The 

Triassic Chinle Formation rests directly (and 

unconformably) on these ancient basement rocks. 

Investigators have not found any rocks deposited on the 

eroded basement surface between Late Proterozoic 

(Precambrian) and Late Triassic time, a period of some 

1.5 billion years (Baars, 1998). 

During Precambrian time, island- arc volcanic rocks and 

related sediments accumulated along the continental 

margin as one lithospheric plate descended under 

another. Compressive mountain building and intrusion 

of granitic rocks and pegmatite dikes followed the 

formation of Earth’s early crust. From the Cambrian 

through Mississippian time (554–320 million years ago), 

relatively thin marine sandstone, limestone, dolomite, 

and shale were deposited, covering much of the North 

American craton. During Pennsylvanian and Permian 

time (320–251.4 million years ago), Colorado was subject 

to a second period of compression and uplift, which 

formed the Ancestral Rocky Mountains. During this 

period of mountain building, the previously deposited 

marine rocks—if ever present in the monument—were 

eroded, transported, and deposited away from the 

monument area in great thicknesses into the Paradox 

Basin. Today, the highly metamorphosed cores of 

ancient mountains lay exposed in Colorado National 

Monument, but remnants of Paleozoic rocks in the 

monument are gone. 

After the Paleozoic, deposition began again as evidenced 

by the impressive display of Mesozoic sedimentary rocks 

in the monument. Triassic- to Cretaceous- age 

sediments were deposited throughout Colorado, though 

this time under largely non- marine conditions until Late 

Cretaceous seas covered the area. During the Mesozoic, 

non- marine sandstone and shale were deposited on 

Precambrian basement rock. Most of the cross- bedded 

sandstone was deposited under desert conditions, and 

shale commonly was deposited in shallow non- marine 

lakes. Thick, marine Mancos Shale and younger near -

shore and non- marine sandstones, shales, and coal beds 

(Mesaverde Group) covered these strata. Although 

Mancos Shale has been eroded from the monument, it 

underlies the nearby Grand Valley. 

Beginning about 70 million years ago, mountain building 

once more affected Colorado. The Laramide orogeny 

began during the Late Cretaceous and continued into the 

middle Eocene Epoch (about 50 million years ago). This 

mountain- building episode caused uplift, folding, and 

faulting in the Colorado Plateau region. Most of the 
 NPS Geologic Resources Division 4 

present- day structural framework for Colorado 

National Monument was formed during the Laramide 

orogeny. 

After the Laramide orogeny, but during a significant part 

of the Cenozoic Era, great volumes of sedimentary 

rocks—particularly soft shales—were slowly eroded 

from the Colorado Plateau. During periods of relative 

tectonic quiescence, rivers in the area tended to meander 

and began to carve broad valleys into the areas underlain 

by Mancos Shale, such as Grand Valley. Regional 

uplift(s) in the late Cenozoic caused rivers to entrench 

their meanders into the more resistant rocks beneath the 

Mancos Shale, forming such notable features as the 

Grand Canyon, Westwater Canyon, and the Goosenecks 

of the San Juan River. 

This process of exhumation as a result of regional uplift 

continued during the Pleistocene Epoch and persists 

today. Erosion of the canyons on the northeastern edge 

of the Uncompahgre Plateau at Colorado National 

Monument is beginning to remove the Mesozoic rocks 

from the plateau. And for a fourth time, Precambrian 

rocks are being exposed. 

Today, canyon- cutting processes, including flash 

flooding, are creating the magnificent scenery of 

Colorado National Monument. Geologic features are a 

result of the process of erosion, which creates both its 

beauty and its hazardous conditions. Intense summer 

thunderstorms are common and quickly produce large 

volumes of water that rush through the canyons of the 

monument. These flash floods erode the canyons, and 

flood buildings and roads in their paths. Another 

erosional process, mass wasting, works on unstable cliffs 

such as the Wingate Sandstone, producing rockfalls that 

pose safety hazards in areas where visitors travel, notably 

at overlooks and along Rim Rock Drive where 

undercutting during construction of the road has 

destabilized the cliffs. In addition, expansive clays, 

present in rocks in the monument, swell when wetted, 

and increase the probability of landslides in the area. 
 COLM Geologic Resource Evaluation Report 5

Geologic Issues 

On June 23 and 24, 1998, a geologic resources inventory scoping session was held at 

Colorado National Monument to discuss geologic resources, address the status of 

geologic mapping, and assess resource management issues and needs. In addition, on 

September 9 and 10, 2002, a geoindicators scoping meeting was held to identify active 

geologic processes and human impacts on these processes. The following section 

synthesizes these scoping results, in particular, those issues that may require attention 

from resource managers. 

Abandoned Mine Lands 

In the early 1990s, as part of an inventory effort, staff 

from the NPS Geologic Resources Division (GRD – 

previously known as Mining and Minerals Branch) 

investigated five sites at Colorado National Monument: 

(1) Kodel Gold Mine, located at the north end of the 

monument in Kodels Canyon; (2) Ella Lode, a vertical 

mine shaft located 50 feet (15 m) below Rim Rock Drive 

near the southeast boundary of the monument; (3) Red 

Canyon Overlook borrow pit, noticeable from a bluff just 

west of Red Canyon Overlook; (4) Columbus Canyon 

borrow pit, located northwest of the head of Columbus 

Canyon but not visible from any nearby vantage points; 

and (5) Columbus Canyon drainage diversion, a mined 

tunnel underneath Rim Rock Drive that diverts 

intermittent drainage at the head of Columbus Canyon. 

The first two sites appear to have been mined for 

precious metals (e.g., gold and silver). Material from 

borrow pits was used for road maintenance (John 

Burghardt, NPS Geologic Resources Division, written 

communication, 2003). 

Upon investigation, GRD staff determined that one of 

the five sites, Kodel Gold Mine, merited further 

mitigation because of moderate visitation to the site and 

its close proximity to a residential area. Park staff 

constructed a locked gate at the entrance of the mine in 

1987. In 1989, three teenagers died in a nearby mine, not 

far from the park, as a result of breathing oxygendeficient air when they bypassed a vandalized gate. 

Similarly, the winzes (deeply inclined passageways) in 

Kodel’s mine could be potential air traps. Park managers 

were concerned that if curious, but unaware, visitors 

breached the gate at the mine, a fall into one of the 

winzes could result in a life- threatening injury or 

entrapment in bad air. 

Park and GRD staff decided that, though neatly installed, 

a hacksaw or portable torch would easily cut the 1- inch 

(2.5- cm) steel tubing of the gate at Kodel’s mine, leaving 

two particularly hazardous winzes accessible to the 

public. In order to preserve the historical integrity of the 

site, staff agreed that the safest alternative for mitigation 

was to backfill the winzes and leave the gate in its present 

condition. Backfilling the winzes would remove the 

primary hazards, leaving only a gated 18- feet (5.5- m) 

deep, nearly horizontal adit in very stable rock, which 

would allow visitors to look through the gate and still get 

the sensation of being in a mine. 

The winzes at Kodel’s mine afforded an excellent 

opportunity to test the use of polyurethane foam for 

plugging mine openings in a remote area (figure 2). The 

components of the plugging operation were backpacked 

to the site where they were hand mixed, as opposed to 

using conventional mechanized methods where 

vehicular access is not an issue. The success of this 

project had far- reaching implications for portable, 

economic closures in other remote and environmentally 

sensitive areas in the National Park System. Polyurethane 

foam is now the primary closure method where backfill 

is not feasible (John Burghardt, NPS Geologic Resources 

Division, written communication, 2003). 

As a side note, although NPS staff had previously 

inventoried Kodel’s Gold Mine for endangered species, 

partway though the closure (on January 8, 1991), two bats, 

believed to be Townsend’s big- eared bats (Plecotus 

townsendii), emerged from one of the winzes. At the 

completion of the project, one bat remained in the upper 

portion of the mine (figure. 3). 

Biological and Physical Soil Crusts 

Biological and physical soil crusts are a distinctive 

resource in Colorado National Monument and should be 

preserved because of their potential to protect 

underlying fine material from wind erosion; fix 

atmospheric nitrogen for vascular plants; provide carbon 

to the interspaces between vegetation; secrete metals that 

stimulate plant growth; capture dust (i.e., nutrients) on 

their rough, wet surface areas; and decrease surface 

albedo. Also, depending on soil characteristics, biological 

crusts may either increase or reduce rates of water 

infiltration. By increasing surface roughness, soil crusts 

reduce runoff, thus increasing infiltration and the 

amount of water stored for plant use. 

In order to protect and preserve soil crusts, it would be 

beneficial to identify the locations of these crusts and 

incorporate this information into the GIS of the park. A 

spatial inventory of crusts would enable park managers 

to plan the placement of trails and educate visitors 

appropriately. Since these crusts are more abundant in 

areas that are predominately piñon and juniper, there is 

concern that without proper consideration, fire 
 NPS Geologic Resources Division 6 

management plans related to prescribed burns or 

mechanical fuel reduction could have a negative impact 

on soil crusts. Linking the locations of these crusts to the 

fire management plan could address these concerns. 

Human impacts on biological and physical soil crusts 

have been intense in some of the canyon areas in the 

monument. For example, starting in the 1930s, a herd of 

bison (up to 60 head) grazed throughout the canyon 

areas and disturbed soil crusts. The herd was an attempt 

by the first custodian of the park, John Otto, to 

encourage visitors to come to Colorado National 

Monument however, this practice ended in the 1980s. In 

addition, damage to crusts occurred in CCC camps and 

along major trail corridors. 

Visitor use disturbs soils and biological soil crusts, 

resulting in compaction or increasing the susceptibility of 

the soils to erosion and the invasion of nonnative plants. 

These impacts occur on trails; in areas adjacent to trails, 

roads, and overlooks; during cross- country travel, 

including access to climbing areas; through proliferation 

of visitor- created trails (social trails); at backcountry 

campsites; around developed areas; and by off- road 

vehicle use. 

One method of addressing visitor use impacts would be 

to develop an educational program about biological and 

physical soil crusts. To maximize effectiveness the 

program should emphasize “hotspot” areas and target 

hikers and climbers. 

Erosion 

The process of erosion, a fundamental natural process 

that has been operating for millions of years, created the 

landforms of Colorado National Monument and 

developed the foundation for of the present- day 

ecosystem. Erosion and the susceptibility of rocks to 

erosion are both variables in landscape evolution, 

exposing fossils to natural deterioration and possible 

vandalism. Depending on thickness, the least erodible 

rock formations in the monument form cliffs, canyons, 

and ledges. The more erodible formations tend to form 

slopes; they also contain the better part of the 

monument’s paleontological resources (table 1). 

Although erosion is a fundamental and complex natural 

process, it is strongly modified (generally increased) by 

human activities. Human influences on soil and sediment 

erosion in Colorado National Monument occur on a 

local scale, the primary influence being Rim Rock Drive 

(e.g., road cuts and increased runoff). The proliferation 

of social trails, which is tied to increasing visitation, also 

causes erosion on a local scale (e.g., in Monument 

Canyon, lower Liberty Cap Trail, No Thoroughfare 

Canyon, trail between the visitor center and Book Cliffs 

View, and Alcove Trail). Furthermore, the use of 

climbing equipment, such as bolts and pitons, results in 

erosion of rock faces; impacts are both aesthetically 

displeasing and physically damaging to the rocks. 

TABLE 1. Erodibility of Rocks at Colorado National 

Monument 

Erodibility Formation 

Precambrian 

Kayenta Formation 

Dakota Sandstone 

Wingate Sandstone 

Entrada Sandstone 

Burro Canyon Formation 

Morrison Formation 

Wanakah Formation 

Chinle Formation 

Least erodible 

Most erodible Mancos Shale 

Note: Mancos Shale is not exposed within the monument, but is 

present in the adjacent Grand Valley. Within the uplifted formations 

of the monument, it has been entirely eroded away. 

Expansive Soils and Clays 

The Brushy Basin Member of the Morrison Formation 

and some of the younger formations contain expandable 

clays that can swell when wet. For example, watering 

lawns in the Redlands area, outside but adjacent to the 

park, has locally caused the expansion of soils and clays 

damaging homes and roads. This is evident, throughout 

the area covered by the Grand Junction 7.5- minute 

quadrangle. 

Smectitic clays (e.g., bentonite) are alternation products 

of volcanic ash and therefore retain the radioactivity of 

the volcanic ash. In 1999 investigators used a portable 

gamma ray spectrometer to detect concentrations of 

gamma ray–producing radioactive elements in the strata 

that have the highest occurrence of expansive clays and, 

therefore, are those most prone to landsliding (Cole and 

others, 1999). 

Flash Floods 

Flash floods affect all park management divisions (e.g., 

maintenance, interpretation, and resource management). 

They present a serious geologic hazard not only to park 

visitors on foot in narrow canyons, but also to houses 

and roads north of the park close to flood- prone 

ephemeral streams that exit through narrow canyons 

into the Redlands area. 

Collaboration among park staff, the U.S. Geological 

Survey, Colorado Geological Survey, and local geologists 

and hydrologists could result in a long- term plan for 

educating the public about flash floods. These 

educational plans could be modeled after fire 

management plans, which have been successful in the 

past. 

Studies pertaining to flash- flood recurrence intervals are 

needed to help quantify the risks associated with flash 

flooding, particularly with respect to roads, buildings, 

and visitor safety. These studies in Colorado National 

Monument would benefit the Grand Junction area by 

determining the risks associated with external 

development at the mouths of canyons. 
 COLM Geologic Resource Evaluation Report 7

Repeat photography is an option for gathering baseline 

information on flash floods. Because floods leave debris, 

photography during flood events may not be necessary. 

Photos taken after the event could capture the extent and 

magnitude of flood events. 

Modeling flash flood processes for drainages in 

Colorado National Monument would also yield valuable 

information to park management and the surrounding 

community. In order to verify flash flood models, data 

collection that measures peak flow is needed. Installation 

of crest- stage gages and the rating of stream channels 

using the step- backwater method would provide the 

basic data needed to support flash- flood models. The 

U.S. Geological Survey and the local community may be 

interested in participating in flash flood modeling 

projects. 

Groundwater Level and Quality 

Water is scarce in Colorado National Monument, and 

wildlife and plants, including threatened and endangered 

species such as the Winkler cactus, depend upon it. 

Groundwater supplies seeps and springs, which are areas 

of high biodiversity. Groundwater levels are very 

important on a local scale, for example, in Ute Canyon, 

where groundwater discharge feeds plants on the 

southern side of the canyon. 

Groundwater level is significant for management because 

a decrease in groundwater level could have a direct effect 

on the monument’s seeps and springs. Quantifying 

groundwater level is important because park managers 

could use this information for planning and future 

decision making as it relates to development outside the 

monument’s boundary. 

Baseline data are needed in order to detect groundwater 

depletion caused by increased development in areas 

bordering Colorado National Monument, such as Glade 

Park. Increased extraction of groundwater could have a 

negative effect on seeps and springs and the organisms 

that rely on them. Upon determining a baseline 

groundwater level, periodic monitoring would be 

beneficial. At a minimum, a network of wells should be 

monitored at least annually, but preferably quarterly or 

even more frequently. Because the monument does not 

have a monitoring well, one option would be for park 

managers to attain permission from homeowners in 

Glade Park to monitor water levels in private wells. The 

U.S. Geological Survey has capabilities to advise or 

participate in this activity. 

Another significant source of information would be to 

identify the groundwater recharge area for Colorado 

National Monument. Determining the rate of 

groundwater withdrawal in the recharge area will be an 

important step in understanding the impacts of outside 

development on groundwater resources of Colorado 

National Monument. 

Baseline data should also include water chemistry at 

seeps and springs, and at selected wells in Glade Park. 

Groundwater from samples from the Entrada Sandstone 

or the Entrada–Wingate sandstones has a soft sodium 

bicarbonate water quality with hardness of less than 50 

ppm (parts per million) (Lohman, 1965). Groundwater 

from the Morrison Formation is soft sodium 

bicarbonate–sodium sulfate water. Water from these 

aquifers is good for domestic use, but the high sodium 

content may be harmful to certain plants or crops. The 

Burro Canyon–Dakota sandstone aquifer contains 

generally brackish or salty water. 

Changes in land use and water may pose threats to 

groundwater quality. For example, changes in 

groundwater chemistry could affect organisms at seeps 

and springs. Although the risk of contamination is 

probably not high at present, this could change in the 

next 50 to 100 years. As Glade Park grows, the chances of 

groundwater contamination will increase. The risk also 

depends on the kinds of changes that take place in land 

use and water use in the recharge area, as some changes 

will pose more serious threats than others 

(see Appendix C). Park staff have hand- drawn locations 

of seeps and springs on 7.5- minute topographical maps. 

These data are assumed to have been collected at the 

same time as a vegetation study in 1984. 

Hydrocompaction 

Surficial deposits that contain debris from the Brushy 

Basin Member of the Morrison Formation are 

particularly susceptible to shrinking, swelling, and 

hydrocompaction; these deposits make an unstable base 

for roads and buildings. Quaternary deposits, such as 

eolian sand, are probably susceptible to 

hydrocompaction and possibly piping. Cienaga deposits, 

which have been deposited by eolian or sheetwash 

processes in marshy areas, are poorly suited for 

supporting roads and structures or for the efficient 

operation of septic systems. Hazards commonly 

associated with these deposits include seasonal high 

water tables, low bearing capacity, and the presence of 

sulfate minerals, which deteriorate untreated concrete 

and steel. The Brushy Basin Member, which underlies 

Cienaga deposits, is relatively impermeable and contains 

abundant expansive clay (Scott and others, 2001a). 

Mineral Resources 

Federal mineral leasing is prohibited within the 

boundaries of Colorado National Monument as is the 

location of new mining claims. All lands within 

Monument boundaries are federally owned therefore 

there is no potential for private mineral development 

within Monument boundaries. 

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 

Colorado National Monument, the area is bordered on 

the northeast, east, and southeast by the Piceance Creek 

Basin which is a primary target for proposed oil shale 

leasing and development. The Uinta Basin is also 
 NPS Geologic Resources Division 8 

located somewhat farther to the northwest of the park 

and may also be subject to oil shale leasing. Therefore, 

the park could be impacted from such development. 

Coal 

The largest reserves of bituminous coals are found 

primarily in the Upper Cretaceous Dakota and 

Mesaverde Groups in western Colorado. A measured 

section of Dakota Sandstone in No Thoroughfare 

Canyon contained minor beds of lignite 1–4 inches (2.5–

10 cm) thick and a 6- inch (15- cm) bed of lignite at the 

top of a 58- foot (18- m) shale section. A 76- foot (23- m) 

measured section along old East Creek road contained a 

2- foot (0.6- m) and a 3- foot (0.9- m) layer of “lignitic” 

shale (Lohman, 1965). Some low- grade, thin coal seams 

exist along the Gunnison River valley, but mining ceased 

because better bituminous coal was abundant elsewhere 

(e.g., the Grand Mesa and the Book Cliffs coal fields) 

(Lohman, 1965). The Mesaverde Group, a major coal unit 

in southwestern Colorado, has been eroded from the 

Uncompahgre Plateau. 

Oil and Gas 

Colorado National Monument is located in Mesa 

County, Colorado. 2004 data show over 46,000 acres of 

mineral leases in Mesa County. Garfield and Rio Blanco 

Counties are two of the most productive gas areas in the 

state and are located to the north of Mesa County. 

Garfield County expects that the number of gas wells in 

the county will double in the next ten years with many 

western slope counties following suit. 

Sand and Gravel 

Abundant sand and gravel resources are in the vicinity of 

Colorado National Monument (Scott and others, 2001a) 

and have been and are being developed in the Grand 

Valley. Most of these deposits contain rounded, wellsorted pebble- cobble gravel composed of basaltic rocks, 

quartzite, micaceous red sandstone, fine- to mediumgrained granitic rocks, shale clasts of the Green River 

Formation, and other volcanic rocks. About 3.3 to 6.6 

feet (1 to 2 m) of sand, possibly of eolian origin, overlies 

the gravel. The gravels may be suitable for road base, but 

probably are not suitable as an aggregate for concrete 

and asphalt (Scott and others, 2001a). Drill- hole data 

suggests that the thickness of the gravel deposits may 

exceed 23 feet (7 m) locally. 

Other Mineral Deposits 

Attempts were made to mine copper ore in Unaweep 

Canyon to the south of the monument, but the mines 

were abandoned. In the past, Entrada Sandstone was 

quarried from several places in and near Colorado 

National Monument, providing building stone for some 

of the older buildings in the monument and curbstone 

for Rim Rock Drive (Lohman, 1965). Mica—a mineral 

used in paints, insulation, and greases—was mined until 

1950 from an operation about 6.5 miles (10 km) southwest 

of Grand Junction. This mine was known as the 

Williamson Mine (Lohman, 1965). 

Outdoor Classroom 

Colorado National Monument could serve as a premier 

outdoor classroom. Geologic features at the monument 

illustrate a long, dynamic history of Earth’s processes 

and their effects on the geology of the Colorado Plateau. 

Particularly notable are the rock layers, which visibly 

record geologic history, and the distinctive monoliths 

and canyon walls that inspired the establishment of the 

monument (Colorado National Monument GMP, draft, 

September 2003). 

The structural complexities of the Ancestral Rocky 

Mountains and the Laramide orogeny also are quite 

pronounced at Colorado National Monument. 

Monoclines, anticlines, synclines, faults, fractures, and 

joints all provide an excellent outdoor classroom for the 

structural geology students and professional geologists 

(figure 5). 

Colorado National Monument is a world class setting for 

the study of structural geology, sedimentology and 

stratigraphy. Communicating this to the scientific and 

academic community could generate a large amount of 

data and information for making management decisions 

regarding the natural resources of the monument. This 

information can also be used in preparing interpretive 

materials and exhibits at the visitors center, overlooks, 

and along trails. 

Paleontological Resources 

Because a park- wide fossil inventory has not been 

conducted and a monitoring program has not been 

established, the extent of risk, exposure, and fossil loss in 

the monument cannot be measured at present (Colorado 

National Monument GMP, draft, September 2003). 

Some data from preliminary inventories are available, 

however, and document the kinds of paleontological 

resources found at Colorado National Monument. For 

instance, during a paleontological resource inventory of 

the Morrison Formation, Callison (1977) documented 14 

fossil localities in the monument. Investigators 

introduced new discoveries of trace fossils at the 

geologic resources inventory workshop in 1998 

(Appendix B). Further studies of these trace fossils could 

provide additional clues to the paleo- ecosystem of the 

Uncompahgre Plateau and climate and habitat changes 

through time. Moreover, in 2001 Scott and colleagues 

presented a preliminary inventory of paleontological 

resources at the monument, which indicated the 

potential for future fossil discoveries (Scott and others, 

2001b). 

In 2000 G. F. Engelmann and A. R. Fiorillo resurveyed 

the sites documented by Callison (Engelmann and 

Fiorillo, 2000). Englemann indicated that the specimen 

at one of the localities had been removed (personal 

communication toVincent Santucci (chief ranger, 

GWMP), 2000). This incident illustrates the potential for 

loss of fossils at Colorado National Monument and 

highlights the need for a systematic inventory and 

monitoring program. 
 COLM Geologic Resource Evaluation Report 9

An inventory of fossil resources at Colorado National 

Monument may include identification of areas most 

susceptible to potential threats (e.g., vandalism and 

erosion), intervention thresholds for protecting and 

preserving fossils, and protocols for recovering and 

documenting fossils after intervention. An agreement 

with the Museum of Western Colorado, or other 

qualified institution, would aid in storing, protecting, and 

making available to researchers the paleontological 

specimens collected at Colorado National Monument. 

Incorporating new knowledge of paleontology, resulting 

from an inventory, into interpretation, education, and 

outreach at the monument would enhance visitor 

enjoyment. In addition, the park could determine 

localities from which fossils have been found, document 

localities, fill out paleontology locality forms, and 

conduct condition assessment to meet GPRA goal 1A9. 

Seismicity and Eolian Sediments 

Although seismicity and eolian (wind- blown) sediments 

are of low management significance, having a seismic 

station and eolian sediment monitoring stations in the 

park would have scientific value and encourage 

collaboration between the park and the local academic 

community (see Appendix C). 

Slope Failure 

Slope failure includes landslides, rockfalls, and debris 

flows, which are an integral part of the landscape at 

Colorado National Monument. Slope failure occurs 

continuously throughout the monument, although not 

all rock units disintegrate at the same rate. In general 

slope failure creates piles of rubble that have greater 

permeability and porosity than the original surfaces, 

increasing water- infiltration potential and creating 

“new” land surfaces upon which habitats can evolve. 

Old landslide deposits partly veneer all sides of Black 

Ridge and have flowed across lower stratigraphic units 

onto the floor of Monument Canyon. They also locally 

cover the dip slope of the Morrison–Burro Canyon–

Dakota Formations. These old landslides may be found 

at about 0.6 to 0.9 miles (1 to 1.5 km) south of the 

northern park boundary and 2.5 to 3.1 miles (4- 5 km) 

south of the northern border of the map area. Although 

many of these landslides probably were generated during 

previous wetter climatic episodes and seem relatively 

stable now, bulges in road cuts along Rim Rock Drive 

suggest that these slides may have been reactivated after 

road construction (Scott and others, 2001a). 

Slope failure is a natural process, which is exacerbated by 

human activities, such as the construction of Rim Rock 

Drive and vibration from heavy vehicles (e.g., trucks, 

tour buses, and school buses) on the road. Slope failure is 

a constant maintenance issue along Rim Rock Drive 

(Appendix C). Rim Rock Drive is an important park 

resource, which facilitates public enjoyment and the 

ability to view the monument. Slope failure is a concern 

for park managers, particularly with respect to potential 

road failure. Rockfalls also are a concern because of 

visitor safety, particularly along Rim Rock Drive and at 

overlooks. 

A geologic assessment is needed along the Serpents Trail, 

a trail requiring “massive repair.” Public safety and 

geologic issues along the trail include rockfalls from 

climbing. Such impacts are a degradation of a natural 

resource and are an issue with respect to maintaining the 

monument’s viewshed. 

Unstable cliffs formed by Wingate Sandstone, the 

Kayenta Formation, and the Salt Wash Member of the 

Morrison Formation produce rockfalls that pose local 

geologic hazards. Where road construction has 

destabilized the rock, large rockfalls have occurred, 

damaging Rim Rock Drive. Such a rockfall occurred in 

January 2000 when automobile- size blocks of sandstone 

from the Salt Wash Member slid on thin clay layers and 

toppled onto the road, blocking traffic for at least a 

month (figure 6). 

An inventory of areas along Rim Rock Drive and 

overlooks with high potentials for slope failure would 

have value for inventory, monitoring, and planning. 

High- risk areas could be identified with GPS and 

incorporated into the monument’s GIS. Such an 

inventory would enable park managers to focus on 

particular areas, rather than the entire 23 miles (37 km) of 

road. Also, park staff should monitor cracks in the 

asphalt along Rim Rock Drive and the slow downhill 

movement (creep) of landslide material. 

In addition, fire plays a role in (and could indirectly 

trigger) landslides; therefore, slope failure should be part 

of the fire management plan. The potential to mitigate 

landslides with smaller, prescribed burns should be 

considered. 

Urban Development 

As discussed in the general management plan (draft, 

September 2003), urban development is occurring 

rapidly in areas adjacent to Colorado National 

Monument. How the monument is managed in light of 

this change is the main issue to be addressed in the 

general management plan. Residential areas directly 

adjoin the monument boundary, both in the Grand 

Valley to the north and east of the monument and at a 

lesser density in and near Glade Park to the south and 

west. Residential and other development is likely to 

continue on available private lands near the monument. 

Population growth has placed increasing local and 

regional demands on a national resource. Zoning on 

adjacent private lands is primarily residential but a 

change to commercial zoning could result in 

incompatible “gateway” development. 

Another impact arising from urban development is the 

increase in traffic on Rim Rock Drive, the shortest route 

from Grand Junction to Glade Park. Vibration from 

heavy trucks and busses may cause rockfalls and slope 

failure along the road. Heavy vehicles have some 

difficulty negotiating the sharp curves and the steep 
 NPS Geologic Resources Division 10 

grade. This means that they drive rather slowly and the 

result is traffic congestion from the automobile traffic of 

visitors. 

Recent history shows that a road closure is a reality, e.g., 

Rim Rock Drive was closed for one year when the area 

between the two tunnels was washed out. Park managers 

have a short- term plan for closure of Rim Rock Drive 

but not a long- term plan, in the event that large sections 

of the road are destroyed. A long- term plan for road 

closure, rerouting, maintenance, and visitor safety needs 

to be part of the monument’s general management plan. 

Park staff should work with geologists, engineers, and 

the Federal Highway Administration to plan alternatives. 

The plan for rerouting the road should take into 

consideration geologic strata, location of facilities, and 

wilderness. 

Wetlands 

In 2001, the U.S. Geological Survey collected and 

analyzed water samples from springs and other water 

sources from seven canyons in the monument. However, 

seeps, springs, and wetlands have not been systematically 

inventoried and mapped nor has a fundamental 

assessment been conducted. During the 2001 assessment, 

however, investigators identified locations of many 

wetlands in the monument. The Colorado Natural 

Heritage Program has identified three potential 

conservation areas within the monument that contain 

wetlands (see Appendix C). 

Lithology controls wetlands in Colorado National 

Monument. Groundwater, which feeds wetlands, is 

controlled by rock bedding layers in the underlying 

geologic formations and is recharged by meager 

precipitation. The monument’s drinking water supply is 

obtained from the Ute Water Conservancy District 

(Colorado National Monument GMP, draft, September 

2003), thereby not affecting the local groundwater 

system. The scarcity of wetlands increases their 

importance to plants and wildlife as a source of water. 

Wetlands also provide cooler temperatures. Investigators 

have identified greater plant and animal diversity in 

wetland areas than in other habitats in the monument. 

For example, wetlands are sites of hanging gardens, 

which provide habitat for threatened and endangered 

species (Appendix C). 

Riparian areas are ecologically important in the 

monument’s semi- desert environment, and are used by 

people who are drawn to the shade and occasional water 

found there. Trails in the canyons follow or run parallel 

to riparian areas. As a result, hikers, horses, and 

backcountry campers are prone to damage riparian areas 

and interfere with ecological interactions (Colorado 

National Monument GMP, draft, September 2003). 

Park managers have some information about wetlands in 

the monument from a completed tamarisk survey. To 

date, investigators have identified two wetland areas (i.e., 

upper Ute Canyon and upper No Thoroughfare 

Canyon), totaling about 20 acres (8 ha). Wetlands in the 

monument will be inventoried through the vegetation 

mapping program using GIS (see Appendix C). Locations 

of all wetlands need to be mapped, verified and classified 

during field investigations, and then digitized. 

A significant human influence on wetlands in the 

monument has been the Fruita pipeline, which leaked 

enough water to create artificial habitats ideal for exotic 

plants. In the future, if more water is needed for Fruita, 

reactivating this old water line is a possibility. According 

to the geoindicators report, intense damage to park 

resources would accompany reactivation of the water 

line largely as a result of associated reconstruction 

activities (Appendix C). 

Two reservoirs were constructed to provide water to the 

citizens of Fruita. Although no longer in use, future 

demand for water could result their being reactivated, 

this is a concern for park managers. It is likely that 

construction work (earthmoving) with associated 

impacts would be required for these reservoirs to 

become usable. Also the park may be libel in the event of 

a failure of these reservoirs. In addition, the Civilian 

Conservation Corp (CCC) camp members dammed the 

spring in Monument Canyon, and present- day trails pass 

through wetlands in many canyon areas. 
 COLM Geologic Resource Evaluation Report 11

Figure 2. Polyurethane foam used for mitigating hazardous mine openings. An abandoned mine land site, Kodel’s mine, provided an

excellent opportunity to test the use of polyurethane foam for plugging mine openings in a remote area. National Park Service staff 

tested the strength of the foam with hydraulic jacks placed between a plug and the roof of the adit. NPS photo by John Burghardt. 

Figure 3. Bat in Kodel Gold Mine. Although investigators had previously inventoried the mine for endangered species, partway though 

the closure, two bats, believed to be Townsend’s big-eared bats (Plecotus townsendii), emerged from one of the winzes. At the 

completion of the project, one bat remained in the upper portion of the mine. NPS photo by John Burghardt. 
 NPS Geologic Resources Division 12 

Figure 4. Flash Flood Deposit. Flash flooding is an ongoing process in Colorado National Monument that has occurred in the canyons 

for thousands of years. The deposit preserved in the canyon wall of No Thoroughfare Canyon is graded, which is an indication that the 

deposit was laid during flash flooding events, not debris flows. Photo by Katie KellerLynn. 
 COLM Geologic Resource Evaluation Report 13

Figure 5. Monocline. Colorado National Monument could serve as an outdoor classroom for structural geology. A classic example of a 

monocline (shown in photo), as well as anticlines, synclines, faults, fractures, and joints display the character of the structural 

complexities of the both the Ancestral Rocky Mountains and the Laramide orogeny. Photo by Katie KellerLynn. 

Figure 6. Rockfall Area. Wingate Sandstone, the Kayenta Formation, and the Salt Wash Member of the Morrison Formation produce 

rockfalls that pose local geologic hazards. For instance, a rockfall occurred in January 2000 when automobile-size blocks of sandstone 

from the Salt Wash Member slid on thin clay layers and toppled onto the road. Photo by Katie KellerLynn. 
 NPS Geologic Resources Division 14 

Geologic Features and Processes 

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

and processes in Colorado National Monument. 

Alluvial Fans 

In semiarid environments like that of Colorado National 

Monument, ephemeral streams and debris flows 

commonly deposit gravelly sediment in alluvial fans 

along steep mountain and plateau fronts. Alluvial fans are 

present in two depositional settings in the vicinity of 

Colorado National Monument: (1) A few alluvial fans 

presumably formed where steep- gradient, ephemeral 

streams deposited gravelly sediment along the northeast 

front of the Uncompahgre Plateau. However, overlying 

eolian sand and sheetwash deposits have so severely 

modified the fans that their fan- shaped landforms are no 

longer recognizable. Therefore, these presumed fans are 

called “younger alluvial- slope deposits” and “older 

alluvial- slope deposits” by Scott and others (2001a). (2) A 

few small fan- alluvium and debris- flow deposits of 

Holocene age formed on the floodplain of the Colorado 

River. These types of deposits are not common in the 

area mapped by Scott and others (2001a) because such 

deposits have been removed by the river. 

Eolian Processes 

The action of wind on exposed sediments and friable 

rock formations causes erosion (and abrasion) and 

entrainment of sediment and soil particles. Changes in 

wind- shaped surface morphology and vegetation cover 

that accompany desertification, drought, and 

aridification are important gauges of environmental 

change in arid lands (Berger and Iams, 1996). In the 

vicinity of the monument, eolian sand consists of silty, 

very fine to fine wind- blown sand that blankets areas of 

the Uncompahgre Plateau. Thin, discontinuous deposits 

of eolian sand mantle other surficial deposits and 

bedrock on the upland areas of the Uncompahgre 

Plateau and Redlands area near the Colorado River. In 

the upland areas, deposits of eolian sand locally form 

subdued, stabilized dunes and blankets of eolian sand. 

Eolian sand on the uplands is locally stabilized by piñon 

and juniper trees and in other areas by sage, rabbitbrush, 

bunch grass, and cheat grass (Scott and others, 2001a). 

Erosional Features 

The most important geologic resource in Colorado 

National Monument and vicinity is the beauty of the 

erosional features and rocks exposed at the margin of the 

Uncompahgre Plateau (Scott and others, 2001a). The 

fantastically eroded and vividly colored canyons are 

filled with arches, natural bridges, alcoves, pinnacles, and 

balanced rocks. The sweeping cross- beds of ancient 

sand dunes are preserved in the rock, and panoramic 

views inspire and delight visitors. Many of these features 

are carved into the thick Wingate Sandstone. For 

example, driving along Rim Rock Drive from the west 

entrance of the monument, the road loops past a 

balanced rock of Wingate Sandstone at the head of 

Fruita Canyon. 

From the overview of Fruita Canyon, visitors can see the 

dark- colored, 1.7- billion- year- old Proterozoic rocks; 

the red slopes of Chinle Formation; and the cliffs of 

Wingate Sandstone, which are capped by the resistant 

beds of the lower Kayenta Formation. Desert varnish 

adds to colors and covers many sandstone cliffs. 

Window Rock Nature Trail leads from the northeast 

corner of a campground near the visitor center and 

connects with the scenic Canyon Rim Trail from which 

hikers can see a “window” eroded along a vertical joint 

near the top of the Wingate Sandstone. Independence 

Monument, jutting up 450 feet (137 m) from the canyon 

floor, can also be seen from the Canyon Rim Trail. This 

monument, a thin erosional remnant of a narrow wall 

that once connected mesas to the northeast and 

southwest, separates the two entrances of Monument 

Canyon. 

From Pipe Organ Overlook, visitors can see erosional 

remnants in Monument Canyon that resemble pipe 

organs. And from the Coke Ovens Overlook, they can see 

alcoves forming in the Wingate Sandstone. A short trail 

leads from Artists Point to an overlook of both the Coke 

Ovens and the spires and pinnacles of Monument 

Canyon. 

At the Ute Canyon Overlook, cliffs of mottled salmonand- white Slick Rock Member of the Entrada Sandstone 

and overlying “board beds” unit are visible. Other 

distinctive features carved by erosion include Cold 

Shivers Point, a toadstool- shaped rock balanced on a 

Wingate cliff, and the Devils Kitchen, erosional columns 

of Wingate Sandstone capped by the Kayenta Formation 

in No Thoroughfare Canyon. 

Flash Floods 

Intense summer thunderstorms are common on the 

Uncompahgre Plateau. These storms supply large 

volumes of water in a short period time to canyons of 

Colorado National Monument, where constrictions in 

the canyons increase both the rate of flow and the flood 

heights (Scott and others, 2001a). A single thunderstorm 

may produce enough rain to trigger a flash flood, turning 

a dry creek bed into a ranging, sediment- laden river. 

Flash floods are the principal agent that form and modify 

the present- day canyons and are significant for the 

monument’s ecosystem because of the role they play in 

the formation of the landscape. Boulders more than 6.6 

feet (2 m) in diameter have been moved during historic 

and prehistoric flash floods (Scott and others, 2001a). In 

addition, the Colorado River floods each spring 
 COLM Geologic Resource Evaluation Report 15

following the period of maximum melting of thick snow 

packs in mountainous areas upstream from the 

monument (Scott and others, 2001a). 

Hydrogeology 

Water is a precious commodity to the plants and animals 

living in the semiarid climate of the Uncompahgre 

Plateau. Pinon Mesa, the crest of the Uncompahgre 

Plateau, receives about 25 inches (64 cm) of annual 

precipitation while the slopes and mesa at lower altitudes 

receive between 10 and 25 inches (25 to 64 cm) (Lohman, 

1965). In contrast, Grand Valley is an arid climate, 

receiving less than 10 inches (25 cm) of precipitation 

annually. Most of the precipitation is in the form of 

summer thunderstorms primarily during the highevaporation months of August and September. 

Thunderstorms on the Colorado Plateau are usually 

intense events of short duration. The erosive power of 

flash floods cannot be matched by any other process in 

this desert climate. Where vegetation is scarce, surface 

runoff is rapid and higher drainages often have large 

temporary flows during thunderstorms. The streams that 

drain the plateau are ephemeral, that is, they are typically 

dry except after a sudden rainstorm when runoff fills and 

erodes their banks moving large boulders as well as red 

fine- grained sediment from the Chinle Formation. 

At Colorado National Monument, the ephemeral 

streams flow northeastward towards the Colorado and 

Gunnison Rivers that drain the Grand Valley. Control of 

the drainage patterns on the Colorado Plateau has been 

tied to basement faults in some areas (Maarouf, 1983), but 

at Colorado National Monument, the canyons and 

associated streams do not seem to be influenced by 

faulting (Scott and others, 2001a). The dendritic drainage 

patterns of the canyons are perpendicular to the 

Redlands fault and monocline that form the northeast 

margin of the Uncompahgre Plateau. The canyon 

spacing and thus, drainage pattern, is similar to the 

pattern formed on non- vegetated slopes during initial 

rill and gully formation. Probably, the drainage pattern is 

a composite geometry developed because of the rate of 

uplift, the differential rates of erosion of the sedimentary 

rocks, and the past and present climate. A detailed study 

of the fracture patterns in the Precambrian rocks that 

underlie the canyons and the geometry of the drainages 

may shed additional light on the origin of the drainage 

patterns at Colorado National Monument. 

The sedimentary rocks at Colorado National Monument 

serve as important recharge areas for confined or 

artesian aquifers. Four aquifers provide groundwater in 

the Grand Junction area. In order of importance and 

productivity, these include (1) the Entrada Sandstone, (2) 

Wingate Sandstone, (3) lenses of sandstone in the Salt 

Wash Member of the Morrison Formation, and (4) 

Dakota Sandstone and sandstones in the Burro Canyon 

Formation (Lohman, 1965). These artesian aquifers are 

found northeast of the Redlands fault and monocline 

where they are overlain by younger, relatively 

impermeable strata that serve as confining beds. Because 

of its depositional environment, Entrada Sandstone is 

distributed over a broad areal extent in contrast to 

lenticular, fluvial sandstones in the Morrison Formation 

whose consistency is not predictable. Sedimentary 

structures, unconformity contacts, and pore- restricting 

cement all play roles in defining vertical and horizontal 

permeability in these sandstones. Fractures also increase 

fluid flow through the sandstone. 

The Summerville and Morrison Formations do not yield 

significant quantities of groundwater to wells in the area. 

They do, however, act as confining layers to artesian 

water in the Entrada and Wingate Sandstones. 

The relatively thin sandstone lenses in the Dakota 

Sandstone and Burro Canyon Formation yield small 

quantities of water to a few non- flowing artesian wells 

(Lohman, 1965). Groundwater quantities are limited and 

the water may be salty or brackish. Some areas even 

contain pockets of natural gas. 

The Mancos Shale in the Redlands area serves as a 

confining layer above the Burro Canyon and Dakota 

Sandstone. Generally, the Mancos Shale is not a source 

of water but some weathered zones contain meager 

amounts of highly mineralized water (Lohman, 1965). 

Because of their low permeability, all of these aquifers 

have small yields. For example, most of the wells 

reported by Lohman (1965) operated at rates of 5 to 40 

gallons per minute (gpm). In effect, the wells would be 

considered dry holes in more humid regions. However, 

in the arid Grand Valley where good quality water is 

scarce, these wells are highly valued. 

The artesian aquifers are recharged on the Uncompahgre 

Plateau mainly in areas where streams cross the 

outcrops. A small amount of recharge also will take place 

from precipitation on the outcrop. Recharge is 

dependant primarily on precipitation as all streams on 

the plateau are ephemeral. The rate of recharge to the 

aquifers is probably very small owing to the low 

permeability of the aquifers. The average linear velocity 

of groundwater flow in the Entrada is only about 5 feet 

(1.5 m) per year. At that rate, about 6,500 years are 

required for groundwater to flow from the recharge area 

on the northeastern margin of the Uncompahgre Plateau 

to Grand Junction, and about 3,000 years to flow to the 

large group of wells in the eastern part of the Redlands 

and the western part of Orchard Mesa. In other words, 

groundwater wells are, in effect, “mining” (i.e., depleting) 

groundwater that has been stored in the aquifers. 

Late Cenozoic Uplift 

The Colorado Plateau serves as a classic example of the 

interaction between uplift and erosion. The region was at 

sea level during the Late Cretaceous, but now the deeply 

eroded land surface is at about 1.2 miles (2 km) in 

elevation. The path of the landscape between these two 

endpoints is not clear and geologists have long debated 

the mechanisms, amounts, and timing of uplift and 

erosion. 
 NPS Geologic Resources Division 16 

Recent studies using geographic information system 

(GIS) to map, interpolate, and calculate Cenozoic uplift 

and erosion of the Colorado Plateau during the Cenozoic 

Era provide insights into the development of the 

landscape through time (Pederson and others, 2002). 

Initial results indicate uplift and erosion are spatially 

highly variable with mean values of 6,946 feet (2,117 m) 

for uplift and 1,332 feet (406 m) for net erosion after the 

Late Cretaceous coastal sandstones were deposited. 

Investigators estimate 2,766 feet (843 m) of erosion in the 

past 30 million years, which can account for 2,096 feet 

(639 m) of post- Laramide rock uplift by isostatic 

processes. 

Based on initial results, investigators suggest two endmember scenarios for uplift of the Colorado Plateau. 

First, all uplift on the Colorado Plateau is about 1.2 miles 

(2 km) of Laramide uplift and subsequent erosion, with 

no other sources of later Cenozoic uplift. Second and 

alternatively, proposed mantle sources of middle- late 

Cenozoic uplift are valid, but then with isostatic rebound 

from erosion included, Laramide uplift of the Colorado 

Plateau must then be minor (less than 1,640 feet [500 m]). 

In either scenario, Laramide uplift of the Colorado 

Plateau is much less than that in the neighboring Rocky 

Mountains. This may be expected, considering the 

plateau contains the Unita, Piceance, and San Juan 

sedimentary basins that have subsided, not uplifted, since 

the Cretaceous. Ironically, the problem with the 

Colorado Plateau is that investigators have proposed 

sources for more uplift than there is actual uplift. Initial 

data from Pederson and others (2002) support a 

resolution wherein early Cenozoic events provided the 

bulk of uplift (by whatever mechanism) with little passive 

erosional isostasy in the later Cenozoic. 

Although regional uplift occurred throughout the 

Colorado Plateau during the late Cenozoic and the 

monument area was part of this, investigators have not 

found evidence of post- Laramide uplift in Colorado 

National Monument. However, the absence of evidence 

does not exclude the possibility of minor, local, postLaramide uplift in the monument and vicinity. 

Differential amounts of local late Cenozoic uplift 

superimposed on a background of general regional uplift 

are consistent with evidence found elsewhere in the 

Rocky Mountains of Colorado (Scott and others, 2001a). 

Paleontology and Fossils 

Although investigators have discovered various 

vertebrate, invertebrate, and trace fossils at Colorado 

National Monument, in general fossiliferous exposures 

are not well inventoried. However, in 1977 G. L. Callison 

conducted an inventory of the Morrison Formation in 

Colorado National Monument and documented 14 fossil 

localities that contained bivalves, gastropods, turtles, 

crocodilians, and dinosaurs (Callison, 1977). Most of the 

sites were located in the lower Salt Wash–Brushy Basin 

Members of the Morrison Formation. In 1985 

investigators resurveyed many of the sites, which yielded 

unionid (freshwater) bivalves, gastropods, and dinosaur 

skeletal fragments (i.e., a sauropod caudal vertebra). In 

addition, though much of the formation is poorly 

exposed within the monument, the Morrison Formation 

contains trace fossils such as plant roots and animal and 

insect burrows. In 1995 investigators reported several 

new sites. In 1996 investigators discovered horseshoe 

crab traces within the park in the lower units of the 

Tidwell Member of the Morrison Formation, 

representing the first report of these traces from Jurassic 

rocks (Scott and others, 2001b). Only one site that is 

adjacent to Black Ridge Trail appears to have been 

vandalized (Scott and others, 2001b). 

The Chinle Formation has yielded trace fossils such as a 

theropod track discovered in 1990. Investigators have 

identified other Chinle trace fossils within Colorado 

National Monument such as Scoyenia gracilis, 

Koupichnium nopsca, and Camborygma along with 

crayfish burrows and plant roots (rhizoliths) (Scott and 

others, 2001b). Investigators have found petrified wood 

in the Chinle elsewhere on the Colorado Plateau and 

may be present in the rocks in the monument. 

The Dakota Sandstone contains plant fossil fragments 

and evidence of plant roots and animal burrows; the 

Burro Canyon Formation contains petrified wood. The 

Wanakah Formation contains evidence of plant roots 

and animal burrows. The Entrada, Kayenta, and Wingate 

Formations contain very few fossils. 

In 1965 investigators discovered a Pleistocene mastodon 

tooth in No Thoroughfare Canyon. Unfortunately, the 

current whereabouts of this tooth are unknown. 

Pleistocene- Holocene packrat middens are known from 

the park and can provide important clues regarding the 

paleoecology of the park thousands of years ago. 

Additionally, a number of significant fossil discoveries 

have occurred near the monument. For example, in 1900 

the first skeleton of Brachiosaurus, the giant plant- eating 

dinosaur, was discovered at Riggs Hill just east of the 

monument. The forelimb and shoulder blade of 

Camarasaurus were discovered just north of the 

monument. Though it contains gigantic and bizarre 

dinosaurs that were the most obvious animals of the 

Mesozoic Era, the exposures of the Morrison Formation 

around Fruita are most famous for fossils of smaller 

vertebrates. One of at least two kinds of tiny dinosaurs 

found in the Fruita area is listed in the Guinness Book of 

World Records (Callison, 1987). Adults of the species were 

smaller than an average chicken, lightly built, and could 

run rapidly on their hind legs. Relatives of these 

dinosaurs lived in western Europe. The plant eater, 

Echinodon, has been named positively from Fruita and is 

otherwise known only from England and Portugal. 

During the Late Jurassic, the landmasses of the British 

Isles and the rest of western Europe were attached to 

eastern North America, so these dinosaurs and other 

terrestrial animals were able to move from one place to 

the other. Shortly thereafter, however, the continents 

separated and intercontinental travel became impossible. 
 COLM Geologic Resource Evaluation Report 17

Investigators have identified three kinds of sphenodonts 

(small reptiles) at Fruita: one predator and two plant 

eaters. The plant eaters are members of a new subfamily 

of sphenodonts, based on species discovered at Fruita, 

and have rather flat- topped teeth, wider than they are 

long, that are closely packed along the jaws. The 

dentition resembles the corrugated surface of an oldfashioned washboard, and plant material caught in this 

washboard is pounded and shredded (Callison, 1987). 

In addition to vertebrate animals, invertebrates such as 

aquatic clams and semiaquatic crayfish and snails have 

been found at Fruita. Both crayfish burrows and body 

parts in the sedimentary rocks resemble present- day 

freshwater river ecosystems (Callison, 1987). 

Plants found in the Fruita area support the hypothesis 

that the climate during Morrison time was relatively dry 

because none of the plant remains formed coal deposits 

nor do they indicate swamp or marsh environments. The 

most abundant organic material is conifer wood and 

pollen of Exesipollenites species (related to yews or 

Bennettitiales) and Callialisporites species (related to the 

present- day Norfolk Island pines). Less abundant plants 

include cycadeoids, Bennettitaleans, lycopods, 

bryophytes, Mesozoic “seed ferns,” and ginkophytes 

(Callison, 1987). The suite of plants provides evidence of 

food resources such as seeds, fruits, shoots, and leaves 

available to plant- eating animals. 

A wide variety of fossils is already known from Colorado 

National Monument, and investigators have found many 

other paleontological materials in the area. Hence, a 

systematic inventory of the fossil resources at the 

monument would undoubtedly uncover new material. 

Such an inventory would provide baseline data for a 

monitoring program, which would limit the loss of 

paleontological material in the future, and provide for its 

availability for scientific study. In addition, a 

comprehensive inventory would provide a basis for NPS 

and public understanding of the paleontological 

resources at the monument. 

Tectonic Structures 

The geologic features of Colorado National Monument 

include an impressive sequence of Mesozoic strata, an 

excellent example of a monocline, and one of the only 

places on the Colorado Plateau to observe Precambrian 

basement rocks. The monocline—the simplest type of 

fold where flat beds are offset by a double flexure (Sshaped) bend connection— defines the eastern margin of 

the Uncompahgre Plateau. Uplift and formation of the 

monocline most likely occurred during the Laramide 

orogeny when Precambrian basement faults were 

reactivated. As uplift occurred along these faults, the 

overlying sedimentary strata were bent slowly to 

conform to the new shape of the basement rocks. Uplift 

of the Uncompahgre Plateau brought Precambrian 

schist, gneiss, and granite close to Earth’s surface and 

subsequent erosion has resulted in exposing these units 

at the base of the canyons in the monument (Foos, 1999). 

For the most part, Mesozoic sediments now exposed in 

the monument accumulated near sea level. Now they 

stand about 7,000 feet (2,134 m) higher atop the 

Uncompahgre Uplift, which is another faulted anticline 

initiated in Laramide time and raised with little tilt to its 

present elevation by regional uplift, starting in midTertiary time. On top of the uplift, the sedimentary strata 

rest horizontally and unconformably on 1.7- billionyear- old Precambrian basement rock exposed in the 

floors and lower walls of the deeper canyons. As they 

fold and ultimately break over the basement- penetrating 

reverse and normal faults beneath the northeast flank of 

the uplift, the Mesozoic sediments form the spectacular 

monocline, a textbook example of the Laramide 

structural style. That is, monoclinal folds in the Mesozoic 

sedimentary rocks above high- angle reverse faults in 

basement rocks are characteristically Laramide 

deformation. In contrast, normal faults are commonly 

associated with post- Laramide extension. Some areas on 

the Uncompahgre Plateau margins display only highangle reverse faults, and one area displays only normal 

faults (Scott and others, 2001a). 

The rocks in Colorado National Monument host two 

types of faults: high- angle reverse faults and normal 

faults. High- angle reverse faults dip more than 45° and 

place older rocks above younger rocks. The most notable 

high- angle reverse fault in the monument is the 

Redlands fault. It dips to the southwest between 62° and 

83°, averaging 72°. Based on numerous foliation attitudes 

of Proterozoic rocks, the foliation in both the metasedimentary and meta- igneous body is sub- parallel to 

the northwest- trending mountain front between No 

Thoroughfare and Ute Canyons; but the foliation in 

meta- sedimentary rocks is nearly perpendicular to the 

mountain front in the more northerly canyons. 

Therefore some preexisting structural control may exist 

for the southern part of the Redlands fault. In contrast, 

between Gold Star and Kodels Canyons, where the fault 

progressively changes from a northwestern trend to a 

western trend, no control from metamorphic foliation 

attitudes is apparent (Scott and others, 2001a). 

Unconformities 

Unconformities are gaps in the rock record. The absence 

of rocks of a certain age in a stratigraphic sequence 

represents a time during which no sediment was 

deposited or if deposited has been eroded away. In 

Colorado National Monument, the basal contact of the 

sedimentary Chinle Formation on Proterozoic 

metamorphic rocks (gneisses and schists) is an 

unconformity that represents a break in the rock record 

between about 1.4 billion and 230 million years ago, 

totaling about 1.17 billion “missing” years. 

Valley-Fill Deposits 

The origin of Unaweep Canyon and the affects of 

glaciation vs. valley- fill deposits in the canyons of 

Colorado National Monument remain a controversial 

subject. Further geophysical studies could shed light on 

the extent of glaciation and the association of glaciers on 

the Grand Mesa (to the east) with the Uncompahgre 
 NPS Geologic Resources Division 18 

Plateau. Valley fill studies would shed light on this 

controversy and could improve knowledge of the history 

of drainage development and drainage diversion on the 

Uncompahgre Plateau during Pleistocene and Holocene 

time. In addition, the results of such a study would 

integrate geology with fire protection, defining the fire 

history of the monument using carbon- 14 dating of 

charcoal horizons in the valley fill. Charcoal layers would 

provide an estimate of fire return rates and subsequently 

aid in managing fire threats to historical structures. 

Generally speaking, this study would provide valuable 

information to park managers regarding rates of erosion, 

sources of sediment, past climate change, and fire 

history. 

Holocene and late Pleistocene valley fill deposits that 

cover parts of many canyons in the monument consist 

chiefly of sand and silt of stream terrace alluvium and 

probably sandy, debris flow deposits. Locally the valley 

fill deposits consist of stony colluvium on valley sides as 

well as minor deposits of eolian sand (Qe) and sheetwash 

(Qsw). The valley fill deposits contain several buried, 

weakly developed paleosols and common small (less 

than 0.08 inches [2 mm]) charcoal fragments. Some of 

these paleosols are darker than the rest of the valley fill 

because of the accumulation of organic matter; they 

contain abundant charcoal, presumably from burnt 

woody vegetation. Charcoal not associated with 

paleosols is concentrated at bedding breaks in the 

sediments, but charcoal also occurs within beds. 

The age of the valley- fill deposits, based on calibrated 

carbon- 14 ages, ranges from at least 1,180 to 6,200 years 

BP (before present, actually before 1954) in the upper 

part to at least as old as 10,360 years BP in the lower part 

(Scott and others, 1999). The discovery in No 

Thoroughfare Canyon of a mastodon tooth, which was 

probably eroded from the undated lowest part of the 

unit, is consistent with a late Pleistocene age for the 

lower part of the map unit. Valley- fill deposits are best 

exposed in terrace scarps in the upper part of No 

Thoroughfare Canyon, but isolated remnants are 

widespread in most canyons throughout the monument. 
 COLM Geologic Resource Evaluation Report 19

Map Unit Properties 

This section serves as a critical link between resource managers and the digital geologic 

map of Colorado 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. 

The information provided in this section was taken from 

Geologic Map of Colorado National Monument and 

Adjacent Areas, Mesa County, Colorado (pamphlet; Scott 

and others, 2001a). The prepared table is meant to be a 

quick reference for park staff on the locations, 

descriptions, and significant features of the monument’s 

rock units and deposits. This table is by no means a 

substitute for the descriptions provided in Scott and 

others (2001a). 

Rocks and deposits outside the boundary of the 

monument (e.g., deposits along the Colorado River and 

underlying the Grand Valley) are listed only if they 

provide useful information regarding park management 

(e.g., resource protection, interpretation of geologic 

history, and public education of geologic hazards). An 

explanation for valley- fill deposits is not provided in this 

section but can be found in the “Geologic Issues” 

section. Investigation of this resource is significant for 

reconstructing an environmental record for the past 

10,000 years, including climate, fire, sedimentation rates, 

and biotic response. Alluvial fan (and alluvial slope) 

deposits are discussed in the section “Geologic Features 

and Processes” and are not included here. 
Map Unit Properties Table 

Age Unit Name 

(Symbol) 

Features and Description Location Depositional Setting and Significan

Artificial fill 

(af) Includes compacted and uncompacted material, mostly of silt, sand, and rock fragments; < 33 ft (10 m) thick; beneath Rim Rock Drive >164 ft (50 m) Beneath segments of Rim Rock Drive and reservoir in lower Fruita Canyon 

Alluvium 

(Qal) Chiefly of stream- channel deposits including minor undifferentiated colluvial deposits; includes boulders as large as 6.6 ft (2 m) in diameter; exposed 

thickness about 3.3 to 13 ft (1 to 4 m) 

Along tributary streams of the Colorado River 

Streams, alluvial fans, debris flows, asheetwash 

Flood- plain and stream channel deposits (Qfp) 

Clast- supported, slightly bouldery, pebble and cobble gravel in a sand matrix; thickness may locally exceed 23 ft (7 m) 

Not in monument; deposited along the Colorado River 

River- gravel 

deposits 

(Qrg) 

Chiefly clast- supported, bouldery, cobble and pebble gravel in a sand matrix; clasts generally < 20 in (50 cm) in diameter, sub- rounded to well- rounded, and poorly to moderately sorted; scour- and- fill structures; imbricate clast fabric consistent with the W flow direction of the Colorado River; clasts include the diagnostic moderate- red Maroon Formation and the yellowish- gray Green River Formation among other rock types typical of those transported by Colorado River; thickness 3.3–13 ft (1–4 m) 

Outside monument; hilltops on the S side of Colorado River Indicates erosional history of Colora

River and climate history of the regio

Local gravel 

deposits 

(Qlg) 

Poorly sorted, sub- rounded, clast- and matrix- supported pebble and cobble gravel that locally contains boulders as large as 6.6 ft (2 m); clasts consist 

primarily of metamorphic and igneous Proterozoic rocks and secondarily of sedimentary rocks eroded from the adjacent highlands in the Uncompahgre 

Plateau; locally fills channels as deep as 3.3 ft (1 m) that are cut in the underlying bedrock; thickness as much as 20 ft (6 m) 

Hilltops in the Redlands area 

Deposited at different times between about 42,000 and 480,000 years ago tributary streams of the Colorado Rivprobably includes both stream alluviand debris- flow deposits 

Colluvium, 

undivided 

(Qc) 

Colluvium reflects bedrock and surficial units from which derived; clastsupported pebble, cobble, and boulder gravel with matrix of silty sand, minor clayey silt, and locally, gravelly silt derived from steep slopes; clasts angular to sub- angular and as large as 6.6 ft (2 m) in diameter; max. ~16 ft (5 m) thick 

Along the steeper slopes of mountain front Sheetwash, debris flows, and landslid

Rockfall deposits 

(Qr) 

Include boulders and smaller debris deposited on slopes; clasts typically 3.3–6.6 ft (1–2 m) in diameter, some exceed 39 ft (12 m); clasts on younger rockfall deposits unweathered with light bedrock colors; clasts on older rockfall deposits weathered and coated with a brownish- gray to brownish- black desert varnish; thickness 3.3 ft (1 m) to > 9.8 ft (3 m) 

Along Rim Rock Drive 

At base of cliffs, particularly of WingSandstone (Jwg) 

Younger 

landslide 

deposits 

(Qlsy) 

Mostly intact, active, or recently active earth- block slides, commonly have crescentic headwall scarps; sizes and rock types of the clasts and the grain- size distributions and colors of the matrices reflect those of the displaced bedrock units and surficial deposits; thickness 26 ft (8 m)–115 ft (35 m) 

Not in monument; formed where S side of Colorado River locally cut steep slopes on uppermost Dakota Formation (Kd) and lowermost Mancos Shale (Km) 

Prone to continued movement; posehazard to roads or structures built on bluffs close to the river 

Older landslide 

deposits 

(Qlso) 

Chiefly unsorted and unstratified rock debris characterized by hummocky topography; often complex including debris from the Brushy Basin Member (Jmb), the Burro Canyon Formation (Kb), and the Dakota Formation (Kd); sizes and rock types of the clasts and the grain- size distributions and colors of the matrices reflect those of the displaced bedrock units and surficial deposits; contain blocks as large as 20 ft (6 m) 

Particularly abundant on the slopes of Black Ridge 

Formed on unstable slopes underlain the Brushy Basin Member of the MoFormation (Jmb) 

Sheetwash 

deposits 

(Qsw) 

Chiefly of light- gray sandy and silty clay on very gentle slopes with gradient of ~ 9.8 to 13 ft per .62 miles (3 to 4 m/km) N of the Colorado River where derived by erosion of the Mancos Shale (Km); 9.8–26 ft thick (3–8 m) close to the river, nearly 49 ft (15 m) thick at NE corner of map area 

Grand Valley 

Quaternary 

Eolian sand 

(Qe) 

Silty, very fine to fine wind- blown sand; commonly massive to weakly bedded 

and lacks eolian sedimentary structures, which may have been obliterated by biotic processes; sand derived chiefly from weathering of poorly cemented Slick Rock Member (Jes) and “board beds” unit (Jeb) of the Entrada and Wingate Sandstones (Jwg); lesser amounts derived from sandstone members of the Morrison Formation (Jmt, Jms, and Jmb);, subject to redeposition as sheetwash on slopes; thickness about 26 ft (8 m) 

Blankets upland areas of the Uncompahgre Plateau 

Several climbing dunes are banked agbedrock and are as thick as 16 ft (5 m
Age Unit Name 

(Symbol) 

Description Location Depositional Setting and Significan

Eolian sand and sheetwash deposits (Qse) 

Similar to Qe but contains more abundant clasts; consist chiefly of silty, very fine to fine sand commonly containing scattered granule- to cobble- size fragments from bedrock units exposed upslope, esp. between mountain front and Colorado River; contain discontinuous layers and lenses of poorly sorted clasts; thickness about 16 ft (5 m) 

Mantles level to gently sloping surfaces, and silt, sand, and rock fragments on valley sides and hill slopes 

Quaternary Cienaga deposits 

(Qcg) 

Silty sand, chiefly of eolian or sheetwash origin, deposited in marshy areas; where water table is at or near the surface, evaporation leaves precipitate of alkali crust a few inches thick, white, mostly devoid of vegetation; thickness 3.3 to 9.8 ft (1 to 3 m), 

Marshy places in the Redlands area 

Fed by seeps, generally well vegetateupstream from constrictions of resistbeds of the Burro Canyon Formation and the Dakota Formation (Kd) 

Mancos Shale 

(Km) 

Chiefly medium dark- gray, dark- gray, brownish- gray, and brownish- black fissile shale that weathers to light gray and forms gentle slopes; thickness > 4,495 ft (1,370 m) in W Colorado but < 66 ft (20 m) of lowermost Mancos is 

exposed south of the Colorado River in the map area 

Only lowermost Mancos Shale exposed along the N boundary of the map area near the Colorado River 

Lowermost stratum deposited in a shmarine sub- tidal setting 

Dakota 

Formation 

(Kd) 

20 to 50% sandstone, 5 to 20% conglomerate, 40 to 60% mudstone, and < 5% 

impure coal; four parts (from top to bottom): interbedded sandstone and shale part, sandstone part, mudstone part, and conglomeratic part; upper part transitional with Mancos Shale (Km); thickness at Black Ridge about 102 ft (31 m) where uppermost part of unit has been removed by erosion; total unit thickness estimated at 148 to 164 ft (45 to 50 m) 

Caps Black Ridge and forms a series of low hogbacks in the Redlands area 

Sandstone and mudstone deposited estuaries, tidal channels, distributary channels, bays, lagoons, strandlines, barrier islands 

Cretaceous 

Burro Canyon 

Formation 

(Kb) 

40 to 80% mudstone, 20 to 60% sandstone, and 0 to 15% conglomerate; usually 

upper part dominated by mudstone and forms slopes; lower third to two- thirds dominated by sandstone and forms cliffs; thickness 96 ft (29.3 m) at Black Ridge 

Saddle on Black Ridge Flood plain and lacustrine 

Brushy 

Basin 

Member 

(Jmb) 

85 to 95% mudstone, 5 to 15% sandstone, with trace of limestone; multicolored mudstone forms gentle rounded slopes; thicker channel (sandstone) sequences commonly have small- scale trough cross- stratification and scour surfaces accentuated by basal layers of pebble- size mud chips and granules of chert and quartz; thinner sandstone beds are commonly bioturbated; about 312 ft (95 m) thick 

In the vicinity of Black Ridge and Monument Mesa 

Mud flat to saline lacustrine setting twas locally invaded by highly sinuoufluvial channels 

Salt Wash 

Member 

(Jms) 

30 to 80% sandstone, 20 to 70% mudstone, and traces of limestone; exhibits considerable lateral variation in thickness and rock type; thickness 102 ft (31 m) at Artists Point; within the sandstone portion, thicker sand bodies (up to 16 ft [5 m]) commonly exhibit small- to large- scale trough, tabular- tangential and sigmoidal cross- bedding, and scour surfaces 

Road cuts on Rim Rock Drive S of Highland View Overlook 

Fluvial setting and associated flood pand shallow ponds 

Morrison Formation 

Tidwell 

Member 

(Jmt) 

Laterally variable proportions of multi- colored, interbedded mudstone, 50 to 70%; sandstone, 10 to 40%; limestone, 5 to 20%; forms slopes broken by relatively thin ledges of sandstone and limestone; about 125 ft (38 m) thick at Artists Point 

Morrison Formation consists of three members: Brushy Basin Member(slope- forming upper member), Salt Wash Member (cliffforming middle 

member), and Tidwell Member

(slope- forming lower member); total thickness about 525 ft (160 m) 

In road cuts along Rim Rock Drive between Artists Point and Highland View Overlook 

Deposited in several environments: (fresh to brackish- water lacustrine se(2) beaches in lake- margin settings, afluvial and distributary channel syste

Jurassic 

Wanakah 

Formation 

80 to 90% interstratified mudstone, 5 to 15% sandstone and silty sandstone, 0% to 5% impure limestone, with traces of volcanic ash and gypsum; slopeforming; recognized by distinctive green- over- red colors and by a noticeable reduction of vegetation; thickness 31 ft (9.4 m) thick at Artists Point 

Entire formation exposed at Artists Point 

Non- marine mud flat or shallow lacustrine environment 
Age Unit Name 

(Symbol) 

Description Location Depositional Setting and Significan

“Board 

beds” unit 

(Jeb) 

60–70% interbedded sandstone and 30–40% mudstone; interbedded resistant sandstone and less resistant mudstone form slabby exposures that resemble stack of boards; thickness about 43 ft (13 m) along Upper Monument Canyon Trail 

In road cuts along Rim Rock Drive between Artists Point and Coke Ovens Overlook 

Coastal setting—wet sand flat 

Entrada Sandstone Slick Rock Member (Jes) Consists almost entirely (99%) of cross- bedded sandstone; weathers to form rounded benches or cliffs that are almost totally free of vegetation; thickness 112 ft 

(34 m) along Upper Monument Canyon Trail 

Entrada Sandstone consists of two parts: “boards beds” (prominent white cap) and Slick Rock Member (conspicuous pale- orange, ribbon- like cliffs) 

Isolated hill by the N side of Rim Rock Drive about 131 ft (400 m) W of Red Canyon Overlook 

Coastal eolian setting—dunes and wsand flats (interdune areas) 

Kayenta 

Formation 

(Jk) 

80 to 90% sandstone (throughout), 0 to 10% conglomerate (mainly in upper 

half), and 0 to 10% mudstone (mainly in upper half); commonly forms resistant caps or ledges; thickness about 77 ft (23.5 m) along Upper Monument Canyon Trail 

Rim Rock Drive follows Kayenta Formation ledges in many areas; well exposed in road cuts S of headquarters and above tunnels 

High- energy braided- river systems; sediment transport to the W- NW 

Jurassic 

Wingate 

Sandstone 

(Jwg) 

Consists of about 95% sandstone and about 5% mudstone; typically forms high, reddish- orange cliffs and monuments; thickness 328 ft (100 m) along Upper Monument Canyon Trail 

From W entrance, in road cuts between Chinle Formation (TRc) and the tunnels 

NE margin of a large dune area (erg)of dune complexes (draas) and wet sflats fluctuating in size and shape in accordance with climatic variations 

Triassic 

Chinle 

Formation 

(TRc) 

Interbedded 80 to 90% mudstone, 0 to 10% sandstone, 0 to 5% sandy 

conglomerate, and 0 to 5% limestone; forms distinctive red slopes; thickness 89 ft (27 m) along Upper Monument Canyon Trail 

Exposures in the road cut in Fruita Canyon 

Densely vegetated flood plain or mucontaining localized shallow ponds asmall, shallow, sinuous streams; watetable fluctuations common during deposition 

Lamprophyte 

dikes 

(Yl) 

Slightly altered, thin, dark- greenish- gray to greenish- black dikes; contain 

phenocrysts of biotite, hornblende, and pyroxene in a fine- grained matrix; subparallel and dip to the SE at 50° to 73°; thickness 6.6–9.8 ft (2– 3 m) 

NE part of No Thoroughfare Canyon and at the junction of Red and Columbus Canyons 

About 1,400 million years old 

Meta- igneous 

gneiss 

(Xi) 

Biotite- bearing granitic rock with weak foliation and locally containing large feldspar phenocrysts 

Exposed chiefly in E part of Ute Canyon About 1,721 ± 14 million years ago 

Precambrian Migmatitic metasedimentary 

rocks 

(Xm) 

Chiefly a mixture of schist and migmatitic pegmatite 

N or E entrances to Monument Canyon; the freshest exposures are in the deepest drainages off the trails 

1,741 ± 11 million years old (preliminadate)—probably age of metamorphisnot age of old rocks that eroded to produce sediments 
 COLM Geologic Resource Evaluation Report 23

Geologic History 

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

in Colorado 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. 

Colorado National Monument lies about 66 miles (110 

km) west of the northeastern edge of the Colorado 

Plateau where the Colorado River cuts through the 

steeply dipping strata of the Grand Hogback, marking 

the western border of the Rocky Mountain region (figure 

7). Covering parts of Colorado, Utah, Arizona, and New 

Mexico, the Colorado Plateau is an elevated, mildly 

folded and faulted physiographic province underlain by 

relatively flat- lying sedimentary rocks (see figure 1). The 

structural fabric of gently warped, rounded folds of the 

Colorado Plateau contrasts with the intense deformation 

and faulting of the adjacent terrains. Northeast and east 

of the Colorado Plateau are the jagged peaks of the 

Rocky Mountains, and the Basin and Range province lies 

to the west and south. During the Miocene Epoch, the 

extensional tectonics that created the Basin and Range 

region extended the Mesozoic thrust belt (also called the 

overthrust belt) whose easternmost expression forms the 

western border of the Colorado Plateau. 

Colorado National Monument overlaps the northeastern 

margin of the Uncompahgre uplift, expressed physically 

and topographically by the Uncompahgre Plateau, which 

stretches in a northwest- southeast trending direction for 

90 miles (150 km) and is 27 miles (45 km) wide (Scott and 

others, 2001a). The Grand Valley separates the 

Uncompahgre Plateau from the Book Cliffs and Grand 

Mesa. The Redlands forms a geographic area between 

the Colorado River and the boundary of the 

Uncompahgre Plateau that contains many surficial, 

Quaternary- age deposits (Scott and others, 2001a). 

Faults and folds are not the only prominent structural 

features on the Colorado Plateau. The La Plata 

Mountains, Ute Mountains, and Carrizo Mountains in 

northeastern Arizona, and the Henry Mountains and La 

Sal Mountains in Utah are the result of hot, mobile 

magma material rising up from deep within the Earth 

during the early to middle Tertiary (see figure 8). This 

rising magma squeezed and intruded into cracks and 

fissures in the sedimentary rock and caused the overlying 

layers to bulge upward. These mushroom- shaped 

intrusions of igneous rock are called “laccoliths.” Over 

time, erosion has exposed the inner igneous core of the 

ranges. 

Violent volcanic extrusions of molten material erupted 

onto the Colorado Plateau during Tertiary time. Two of 

the Navajo’s sacred mountains, Mount Taylor near 

Grants, New Mexico, and San Francisco Peak near 

Flagstaff, Arizona, are extinct volcanoes (Baars, 1995). 

Huge eruptions occurred where the San Juan Range sits 

now, and continued into the middle Tertiary. Ash and 

cinders belched from numerous calderas. One large 

caldera extends for several miles north of Silverton, 

Colorado. Today, Animas and Mineral Creeks mark the 

caldera’s margins. Several thousand feet of tuff (volcanic 

ash) and lava flows blanketed the central and eastern San 

Juan Mountains and adjacent regions (Baars, 2000). 

Including rocks that have eroded away, the Colorado 

Plateau has been uplifted about 12,000 feet (3,660 m) 

since the end of the Cretaceous Period (about 66 million 

years ago) (Fillmore, 2000). Some of this uplift occurred 

rapidly, geologically speaking. As the rate of uplift 

increased, so did the rate of erosion. The Colorado 

River, for example, carved its present course within the 

last 6 million years. With uplift, streams throughout the 

Colorado Plateau began to dissect the topography into 

the landscape we see today. 

The regional stratigraphy surrounding Colorado 

National Monument forms a rich tapestry of rock units 

that illustrate this complex geology. Both the strata 

present on the surface and in the subsurface, as well as 

the missing strata in unconformities, record major 

orogenic uplifts and subsequent basin formation in 

western Colorado. The stratigraphy documents a variety 

of environmental conditions: from marine incursions to 

deserts, leaving an array of imprints including tropical 

plants mixed with dinosaur footprints, which are 

overlain by strata containing sharks’ teeth. 

Northwest of the Uncompahgre Plateau, all of the 

geologic time periods except the Silurian Period are 

represented by sedimentary rocks. Precambrian metasedimentary and meta- volcanic rocks underlie the 

Paleozoic sedimentary package. Approximately 400 

million years of time is missing between Cambrian- and 

Precambrian- age rocks. Another 400- million- year gap 

in time separates these Precambrian rocks (i.e., the Uinta 

Mountain Group) from the oldest meta- volcanic 

gneisses. 

Southwest of the Uncompahgre Plateau, rocks 

representing both the Ordovician and Silurian Periods 

are missing, but otherwise, the geologic time scale is well 

represented. At least 850 million years is missing between 

the Cambrian- age Ignacio Quartzite and Precambrianage granite, the youngest Precambrian rock identified in 

southwest Colorado. This 850- million- year time gap is 

300 million years longer than the time represented by the 

Cenozoic, Mesozoic, and Paleozoic Eras combined. 
 NPS Geologic Resources Division 24 

Unlike Tertiary time in the Northwest, the Tertiary of 

the Southwest also includes some igneous rocks. 

At Colorado National Monument, erosion has removed 

all the strata representing the Paleozoic Era and some of 

the Triassic Period. More than 1,155 million years is 

missing between the Chinle Formation and the 1,400-

million- year- old igneous dikes found in the monument, 

and more than 1,355 million years is missing between the 

Precambrian meta- igneous and meta- sedimentary rocks 

found in the canyons and the overlying Mesozoic strata 

(Scott and others, 2001a). The gap in the stratigraphic 

record represents a time of active mountain building 

during the upper Paleozoic when the Ancestral Rocky 

Mountains formed.

Figure 7. Map of Colorado National Monument. Colorado National Monument is part of the Colorado Plateau where the Colorado River cuts 

through the steeply dipping strata of the Grand Hogback, which marks the western border of the Rocky Mountain region.
 COLM Geologic Resource Evaluation Report 25

Geologic Time Scale 

Eon Era Period Epoch Age (Ma) Age of 

Quaternary Holocene 0.01 

Pleistocene 1.81 

Neogene Pliocene 5.33 

Miocene 23.0 

Oligocene 33.9 

Eocene 55.8 

Cenozoic 

Paleogene 

Tertiary 

Paleocene 65.5 

Mammals 

Cretaceous 145.5 

Mesozoic Jurassic 199.6 

Triassic 251.0 

Reptiles 

Permian 299 

Pennsylvanian 318 

Carboniferous Mississippian 359.2 

Amphibians 

Devonian 416.0 

Silurian 443.7 Fishes 

Ordovician 488.3 

Phanerozoic 

Paleozoic 

Cambrian 542.0 Invertebrates 

Proterozoic 2,500 

Archean 2,500–3,800? 

Hadean 

Also known as Precambrian 

3,800–4,600? 

Figure 8: Geologic Time Scale

Notes: Dates are in millions of years (Ma) and reflect the International Union of Geological Sciences (IUGS) International Stratigraphic 

Commission (ICS) International Stratigraphic Chart (2003) at http://www.stratigraphy.org/chus.pdf. Exceptions include the boundary between 

Archean and Hadean, which the International Stratigraphic Commission does not list. However, the U.S. Geological Survey lists the 

boundary between Hadean and Archean at approximately 3,800 Ma and the formation of Earth at approximately 4,600 Ma, which are used 

here. Mississippian and Pennsylvanian are terms used primarily in North America, and Tertiary and Quaternary are no longer used by the 

International Commission on Stratigraphy (2003) but are listed here because they are still in common use. 
 NPS Geologic Resources Division 26 

References Cited 

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. 

Aubrey, W.M., 1991, Geologic framework and 

stratigraphy of Cretaceous and Tertiary rocks of the 

southern Ute Indian Reservation, southwestern 

Colorado: U.S. Geological Survey Professional Paper 

1505- B, 24 p. 

Baars, D.L., 1995, Navajo country: Albuquerque, New 

Mexico, University of New Mexico Press, 255 p. 

Baars, D.L., 1998, The mind- boggling scenario of the 

Colorado National Monument—a visitor’s 

introduction: Grand Junction, Colorado, Canyon 

Publishers Ltd., 14 p. 

Baars, D.L., 2000, The Colorado Plateau: Albuquerque, 

New Mexico, University of New Mexico Press, 254 p. 

Berger, A.R., and Iams, W.J., 1996, Geoindicators—

assessing rapid environmental changes in Earth 

systems: Rotterdam, A.A. Balkema, 480 p., 

http://www.gcrio.org/geo/toc.html (December 2003). 

Callison, G.L., 1977, Inventory of fossil vertebrates in 

Morrison Formation rocks on the Colorado National 

Monument: Fruita, Colorado, Colorado National 

Monument Association, 33 p. 

Callison, G.L., 1987, Fruita—A place for wee fossils, in

Averett, W.R., ed., Paleontology and geology of the 

Dinosaur Triangle: Grand Junction, Colorado, 

Museum of Western Colorado, p. 91–96. 

Carpenter, L., 2002, The geology of the Colorado 

National Monument: Trail & Timberline, no. 972 

(September–October 2002), p. 6–7. 

Chenoweth, W.L., 1980, Uranium in Colorado, in Kent, 

H.C., and Porter, K.W., eds., Colorado Geology: 

Denver, Rocky Mountain Association of Geologists, p. 

217–224. 

Cole, R.D., Hood, W.C., and Scott, R.B., 1999, 

Sedimentological reevaluation, high- resolution 

gamma- ray log, and landslide hazards of the 

stratigraphic section at Colorado National Monument, 

western Colorado [abs.]: Geological Society of 

America Abstracts with Programs, v. 31, no. 7, p. A- 283. 

Cole, R.D., and Moore, G.E., 1994, Sequence stratigraphy 

of Cedar Mountain- Dakota interval, western and 

southern Piceance Creek basin, Colorado: American 

Association of Petroleum Geologists Annual 

Convention Program, v. 3, p. 124. 

Cowardian, L.M, Carter, V., Golet, F.C., and LaRoe, E.T., 

1979, Classification of wetlands and deepwater habitats 

of the United States, FWS/OBS- 79/31: Washington, 

D.C., U.S. Department of the Interior, Fish and 

Wildlife Service. 

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

paleogeography, and paleoclimate of the Western 

Interior, in Caputo, M.V., Peterson, J.A., and Franczyk, 

K.J., eds., Mesozoic systems of the Rocky Mountain 

region, USA: Denver, Rocky Mountain Section, SEPM 

(Society for Sedimentary Geology), p. 133–168. 

Engelmann, G.F., and Fiorillo, A.R., 2000, The 

taphonomy and paleoecology of the Upper Jurassic 

Morrison Formation determined from a field study of 

fossil localities: GeoResearch Forum, v. 6, p. 533–540. 

Fillmore, R., 2000, The Geology of the parks, 

monuments and wildlands of southern Utah: Salt Lake 

City, The University of Utah Press, 268 p. 

Foos, A., 1999, Geology of Colorado National 

Monument: Akron, Ohio, University of Akron, 

http://216.239.37.104/search?q=cache:R2h1ZzrmKEYJ:

www.aqd.nps.gov/grd/edu/foos/colm.pdf+monocline

+Colorado+National+Monument&hl=en&ie=UTF- 8 

(December 2003). 

Fryberger, S.G., Krystinik, L.F., and Schenk, C.J., 1990, 

Tidally flooded back- barrier dunefield, Guerrero 

Negro area, Baja California, Mexico: Sedimentology, v. 

37, p. 23–44. 

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

paleogeography and paleoclimate of the central and 

southern Rocky Mountain region, in Reynolds, M.W., 

and Dolly, E.D., eds., Mesozoic paleogeography of the 

west- central United States: Denver, Rocky Mountain 

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

101–118. 

Lohman, S.W., 1963, Geologic map of the Grand Junction 

area, Colorado: U.S. Geological Survey Miscellaneous 

Geologic Investigations Map I- 404, scale 1:31,680. 

Lohman, S.W., 1965, Geology and artesian water supply 

of the Grand Junction area, Colorado: U.S. Geological 

Survey Professional Paper 451, 149 p. 

Lohman, S.W., 1981, The geologic story of Colorado 

National Monument: U.S. Geological Survey Bulletin 

1508, 142 p. 
 COLM Geologic Resource Evaluation Report 27

Maarouf, A., 1983, Relationship between basement faults 

and Colorado Plateau drainage, in Averett, W.R., ed., 

Northern Paradox Basin—Uncompahgre Uplift: 

Grand Junction, Colorado, Grand Junction Geological 

Society, p. 59–62. 

Murray, D.K., 1980, Coal in Colorado, in Kent, H.C., and 

Porter, K.W., eds., Colorado Geology: Denver, Rocky 

Mountain Association of Geologists, p. 205–216. 

Pederson, J.L., Mackley, R.D., and Eddleman, J.L., 2002, 

Colorado Plateau uplift and erosion evaluated using 

GIS: GSA Today, v. 12, no. 8, p. 4–10. 

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

shallow seas—Jurassic paleogeography in the southern 

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

Peterson, J.A., and Franczyk, K.J., eds., Mesozoic 

Systems of the Rocky Mountain Region, USA: Denver, 

Rocky Mountain Section, SEPM (Society for 

Sedimentary Geology), p. 233–272. 

Peterson, F., and Turner, C.E., 1998, Stratigraphy of the 

Ralston Creek and Morrison Formations (Upper 

Jurassic) near Denver, Colorado: Modern Geology, v. 

22, p. 3–38. 

Pipiringos, G.N., and O’Sullivan, R.B., 1978, Principal 

unconformities in Triassic and Jurassic rocks, Western 

Interior United States—a preliminary survey: U.S. 

Geological Survey Professional Paper 1035- A, 29 p. 

Phillips, W.A., 1986, Cobble aquifer investigations, 

Colorado River Basin Salinity Control Projects: Grand 

Junction, Colorado, Grand Junction Office, U.S. 

Bureau of Reclamation, 20 p. 

Scott, R.B., Harding, A.E., Hood, W.C., Cole, R.D., 

Livaccari, R.F., Johnson, J.B., Shroba, R.R., and 

Dickerson, R.P., 2001a, Geologic map of Colorado 

National Monument and adjacent areas, Mesa County, 

Colorado: U.S. Geological Survey Geologic 

Investigations Series I- 2740, scale 1:24,000, and 

pamphlet, 40 p. 

Scott, R.B., Lidke, D.J., Hudson, M.R., Perry, W.J., Jr., 

Bryant, B., Kunk, M.J., Budahn, J.R., and Byers, F.M., 

Jr., 1999, Active evaporite tectonics in the Eagle River 

valley and the southwestern flank of the While River 

uplife, Colorado, in Lageson, D.R., Lester, A.P., and 

Trugill, B.D., eds., Colorado and adjacent areas: 

Boulder, Colorado, Geological Society of America 

Field Guide 1, p. 97–114. 

Scott, R.L., Santucci, V.L., and Connors, T., 2001b, An 

inventory of paleontological resources from the 

national parks and monuments in Colorado, in

Santucci, V.L., and McClelland, L. eds., Proceedings of 

the 6th Fossil Resource Conference, 

NPS/NRGRD/GRDTR- 01/01: Lakewood, Colorado, 

National Park Service, Geologic Resources Division, p. 

178–202. 

Scott, R.B., and Shroba, R.R., 1997, Revised preliminary 

geology map of the New Castle quadrangle, Garfield 

County, Colorado: U.S. Geological Survey Open- File 

Report 97- 737, scale 1:24,000. 

Turner, C.E., and Fishman, N.S., 1991, Jurassic Lake 

T’oo’dichi’—a large alkaline, saline lake, Morrison 

Formation, eastern Colorado Plateau: Geological 

Society of America Bulletin, v. 103, p. 538–558. 

U.S. Department of the Interior, National Park Service, 

2000, Management policies 2001, NPS D1416: 

Washington, D.C., 137 p. 

Varnes, D.J., 1978, Slope movement types and processes, 

in Schuster, R.L., and Krizek, R.J., eds., Landslides, 

analysis, and control: National Academy of Sciences, 

Transportation and Research Board Special Report 

176, p. 11–33. 
 NPS Geologic Resources Division 28 
 COLM Geologic Resource Evaluation Report 29

Appendix A: Geologic Map Graphic 

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

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

please see included CD or visit the GRE publications webpage: 

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

 COLM Geologic Resource Evaluation Report 31

Appendix B: Scoping Summary 

The following notes constitute the geologic scoping summary for Colorado National 

Monument. The scoping meeting occurred on June 23 and 24, 1998; therefore, the contact 

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

the Geologic Resources Division for current information. 

On June 23 and 24, 1998, staff from Colorado National 

Monument, Mesa State College, the U.S. Geological 

Survey, and the NPS Natural Resources Program Center 

met at Colorado National Monument to discuss mapping 

and other geologic needs. 

Participants 

• Bruce Heise, NPS Geologic Resources Division 

• Bill Hood, Volunteer, Colorado National Monument, 

and Adjunct Professor of Geology, Mesa State College 

• Jack Roadifer, Volunteer, Colorado National 

Monument 

• Joe Gregson, NPS Inventory and Monitoring Program 

• Rick Livaccari, Professor of Geology, Mesa State 

College 

• Patrick Perrotti, Chief, Natural Resources, Colorado 

National Monument 

• Judi Lofland, Interpretation, Colorado National 

Monument 

• Ron Young, Chief, Interpretation, Colorado National 

Monument 

• Bob Scott, U.S Geological Survey 

• Pete Larson, Volunteer, Colorado National 

Monument 

• Steve Hickman, Superintendent, Colorado National 

Monument 

• Jim Johnson, Professor of Geology, Mesa State College 

Scoping Session 

June 23, 1998 

The scoping session was held at Mesa State College, 

Wubben Hall (Weldon Lecture Hall). Steve Hickman, 

Colorado National Monument Superintendent, made 

introductions, which were followed by Joe Gregson, NPS 

Inventory and Monitoring (I&M) Program, who 

provided a program overview and update of the geologic 

resources inventory. Bruce Heise provided an overview 

of the NPS Geologic Resources Division. 

Staff from Colorado National Monument presented 

information about geological resource needs and issues 

at the monument (Steve Hickman) and geological 

resource issues for interpretation (Ron Young). Bob 

Scott of the U.S. Geological Survey (USGS) gave a 

summary of USGS geological mapping and research. The 

opening session also included discussions about other 

cooperators; authors for geologic resource report and 

other papers; deliverables from mapping, cooperators, 

and NPS inventory; and closed with a meeting wrap- up 

and feedback. Following lunch, Bob Scott led a field trip 

in the monument. 

June 24, 1998 

Today’s session was held in Colorado National 

Monument. The meeting opened with NPS and USGS 

business. Discussions from June 23 were continued (as 

needed). In addition, the geology- GIS digital data model 

for Colorado National Monument and fiscal issues were 

addressed. The scoping session ended with meeting 

wrap- up (table 1) and feedback. 

Significant Issues 

The monument is presently being remapped and has a 

strong volunteer support group of local retired geologists 

and faculty from the college to assist in handling park 

geologic needs. Significant issues discussed or visited 

during the field trip include 

1. Management issues such as flash flooding and 

landslides, threats to public safety and historic 

structures stemming from geologic hazards, and 

external development at the mouths of canyons 

2. Exciting new discoveries including new trace fossil 

evidence and the fire history of the area revealed in 

canyon floor sediments 

3. Interpretive display needs, including new “virtual” 

geologic displays in the visitor center 

4. Evaluating research requests, including those from 

mineral development companies 

5. A wide range of fiscal issues, mostly pertaining to the 

costs of digitizing, printing, and distributing the new 

geologic map and report 

The plan now is to follow up on these points and 

reconvene in the fall (table 1). 

One of the geologic features identified during USGS 

mapping at Colorado National Monument and discussed 

at the pilot mapping project meeting in July 1997 (?) was 

the occurrence of charcoal horizons in the valley fill. 

Carbon- 14 dating of these horizons gives a ±50 year 

indication of the fire history of the park. Pat Perrotti, 

resource manager for the park, relayed this information 

to NPS fire specialists, who were enthusiastically 

receptive. As a result of this find, a mid- October site 

meeting has been scheduled to look at the fossil record. 

Attending will be NPS specialists in fire ecology, fire 

protection, and piñon pines. USGS experts on soils, 

paleo- climatology, and sedimentology will also attend. 

This is a direct park management application of 

information obtained through geologic mapping. 
 NPS Geologic Resources Division 32 

Management Needs and Concerns 

• Development outside the boundaries of the park, fire 

development, flash floods 

• No general management plan 

• Request by developers for access to park, not for 

public 

• Public safety on Monument Canyon Trail 

• Resource protection on Serpents Trail (e.g., massive 

repair, geologic and engineering assessments), 

climbing impacts 

Research 

• Which way should geological research go? 

• Proposals 

• Paleontology—new trace fossil 

• In backcountry use GIS for analysis, geologic changes, 

modeling 

• Fire Behavior—look at No Thoroughfare Canyon; on 

October 13–14, the fire ecologists and geologist in 

Colorado National Monument will look at fire history 

• Valley fill—soils, paleo- climatology, carbon- 14 dating 

±50 years, fire return rates based on charcoal layers in 

valley fill 

• Fire threats to historical structures 

• Utility corridors power, water, leaks 

Fiscal Issues 

• In conversations with natural history association 

director (since removed) considerable added expense 

to publish map; too great an investment for natural 

history association 

• USGS publishing maps: I- map produced 

electronically, CD- ROM, Internet, print on demand 

• According to Diane Wells, Chief of Publications, to 

print 3,000 maps would cost $10,000 

• Of 3,000 maps published, USGS takes 1,000, would pay 

$3,300; remaining—$6,700 for 2,000 maps 

• Opportunity for NPS collaboration, if to be digitized 

by USGS, I&M could use various contributions, 

possible ways to enhance selling maps 

Action Items 

Item By Whom Status 

Geologic map Bob Scott, others In progress 

Site bulletins Bill Hood One written, another in draft, others 

planned 

Geologic road log Bill Hood & Grand Junction 

Geological Society 

Completed—visitor center to W. 

entrance station; Scheduled—visitor 

center to east entrance station 

Geologic trail maps Sandy & Bill Hood Planned for autumn 

Revised stratigraphic column handout Bill Hood, Rex Cole In progress 

Simulated geologic field trip Bill Hood In progress, a long- term effort 

Book on geology of Colorado 

National Monument 

Bob and Anne Harding, others? Planned 

CD- ROM based display for lobby Bill Hood, Ron Young, others Dreaming about it 

Revised strigraphic chart for exhibits 

room 

 

Revise roadside display (Fruita 

Canyon) 

 

Roadside display for Artists Point 

Flash Flood display on Old Gordon 

Trail 

 

Valley fill display in upper No 

Thoroughfare Canyon 

 

3- D model 

Road logs (Dinosaur National 

Monument, Moab, Black Canyon of 

the Gunnison National Monument) 

 
 COLM Geologic Resource Evaluation Report 33

Appendix C: Geoindicators Report 

The following excerpts are from the geoindicators report for Colorado National 

Monument. The geoindicators scoping session was held on September 9 and 10, 2002; 

therefore, the contact information and Web addresses referred to herein may be 

outdated. Please contact to the Geologic Resources Division for current information. 

Purpose of meeting 

The purpose of the meeting was threefold: (1) to identify 

significant geological processes and features that are part 

of the park's ecosystem, (2) to evaluate human influences 

on those processes and features, and (3) to provide 

recommendations for studies to support resource 

management decisions, geologic inventory and 

monitoring projects, and research to fill data gaps. The 

scoping meeting was designed to use the participants' 

expertise and institutional knowledge and build on the 

synergy of the participants through field observations, 

group discussion, and the exchange of ideas. 

Government Performance and Results Act (GPRA) Goal 

Ib4 

This meeting satisfies the requirements of the GPRA 

Goal Ib4, which is a knowledge- based goal that states, 

"Geological processes in 53 parks [20% of 265 parks] are 

inventoried and human influences that affect those 

processes are identified." The goal was designed to 

improve park managers' capabilities to make informed, 

science- based decisions with regard to geologic 

resources. It is the intention of the goal to be the first step 

in a process that will eventually lead to the mitigation or 

elimination of human activities that severely impact 

geologic processes, harm geologic features, or cause 

critical imbalance in the ecosystem. 

Because GPRA Goal Ib4 inventories only a sampling of 

parks, information gathered at Colorado National 

Monument may be used to represent other parks with 

similar resources or human influences on those 

resources, especially when findings are evaluated for 

Servicewide implications. 

Geoindicator Background Information 

An international Working Group of the International 

Union of Geological Sciences developed geoindicators as 

an approach for identifying rapid changes in the natural 

environment. The National Park Service uses 

geoindicators during scoping meetings as a tool to fulfill 

GPRA Goal Ib4. Geoindicators are measurable, 

quantifiable tools for assessing rapid changes in earth 

system processes. Geoindicators evaluate 27 earth system 

processes and phenomena that may undergo significant 

change in magnitude, frequency, trend, or rates over 

periods of 100 years or less and may be affected by 

human actions. 

Geoindicators guide the discussion and field 

observations during scoping meetings. The geoindicators 

scoping process for the National Park Service was 

developed to help determine the studies necessary to 

answer management questions about what is happening 

to the environment, why it is happening, and whether it 

is significant. The health and stability of an ecosystem is 

evaluated during the geoindicators scoping process. The 

geologic resources of a park soils, caves, streams, springs, 

beaches, volcanoes, etc.- provide the physical foundation 

required to sustain the biological system. Geological 

processes create topographic highs and lows; affect 

water and soil chemistries; influence soil fertility, hillside 

stability, and the flow styles of surface water and 

groundwater. These factors, in turn, determine where 

and when biological processes occur, such as the timing 

of species reproduction, the distribution of habitats, the 

productivity and type of vegetation, and the response of 

ecosystems to human impacts. 

The 27 geoindicators 

1. Coral chemistry and growth patterns 

2. Desert surface crusts and fissures 

3. Dune formation and reactivation 

4. Dust storm magnitude, duration, and frequency 

5. Frozen ground activity 

6. Glacier fluctuations 

7. Groundwater quality 

8. Groundwater chemistry in the unsaturated zone 

9. Groundwater level 

10. Karst activity 

11. Lake levels and salinity 

12. Relative sea level 

13. Sediment sequence and composition 

14. Seismicity 

15. Shoreline position 

16. Slope failure (landslides) 

17. Soil and sediment erosion 

18. Soil quality 

19. Streamflow 

20. Stream channel morphology 

21. Stream sediment storage and load 

22. Subsurface temperature regime 

23. Surface displacement 

24. Surface water quality 

25. Volcanic unrest 

26. Wetlands extent, structure, hydrology 

27. Wind erosion
 NPS Geologic Resources Division 34 

Additional Information 

• Geologic resource monitoring in the National Park 

System: 

http://www2.nature.nps.gov/grd/geology/monitoring/ 

index.htm. 

• Detailed descriptions of the 27 geoindicators: 

http://www2.nature.nps.gov/grd/geology/monitoring/

parameters.htm. 

• IUGS Geoindicators Initiative: 

http://www.lgt.lt:8080/geoin/welcome. 

Park Selection 

The geoindicators scoping meeting in Colorado National 

Monument grew out of a technical assistance request, 

which park managers submitted to the Geologic 

Resources Division. The request was fourfold: (1) to 

identify human/outside influences on the park's geologic 

resources, (2) to quantify flash floods and other geologic 

hazards, (3) to identify research to better understand 

geologic resources, and (4) to request funding for a 

Geoscientist- in- the- Park (GIP). Staff at GRD 

recognized the connection between the request and the 

geoindicators scoping process, so it was agreed to carry 

out a scoping meeting. In addition Colorado National 

Monument was selected for is its unique geologic 

resources, park setting, and human use. 

Summary of Results 

Issues surrounding each geoindicator are identified, and 

have been rated by participants with respect to 

ecosystem importance ecosystem and human influence 

(table 1). Park staff rated the significance for park 

management. A compilation of the notes taken during 

the scoping session and the opening session and field trip 

are included in the appendices. These notes highlight 

additional information regarding geoindicators that may 

be useful to park managers. 

Geoindicators with Importance to Park Ecosystem 

Groundwater Level 

Water is a rare resource in Colorado National 

Monument, wildlife and plants, including T&E species, 

depend upon it. Groundwater supplies seeps and 

springs, which are areas of high biodiversity. Locally 

groundwater levels are very important, for example, in 

Ute Canyon, where the south canyon- side gets 

groundwater discharge that feeds plants. 

Slope Failure 

Slope failure includes landslides, rockfalls, and debris 

flows, which are an integral part of the ecosystem at 

Colorado National Monument. Slope failure happens 

continuously throughout the park, although not all rock 

units disintegrate at the same rate. In general, slope 

failure creates piles of rubble that have greater 

permeability and porosity than the original surfaces, 

which increases infiltration potential and creates "new" 

land surfaces upon which habitats can evolve. 

Soil and Sediment Erosion 

The process of erosion created the landforms of 

Colorado National Monument. It is a fundamental 

natural process that has been operating for millions of 

years, and the development of the present- day 

ecosystem is an outcome of the processes of erosion. 

Stream Channel Morphology, Streamflow, Stream 

Sediment Storage and Load 

The primary reason that these three geoindicators are 

significant for the park's ecosystem is because of the 

roles they play in the formation of the park's landscape, 

particularly canyons. The significance of these three 

geoindicators is best appreciated during flash floods. 

Wetlands Extent, Structure, and Hydrology 

There is a lithologic control on the wetlands in Colorado 

National Monument. The scarcity of wetlands increases 

their importance to plants and wildlife as a source of 

water. They also provide cooler temperatures. Greater 

plant and animal diversity have been identified in 

wetland areas, and they are sites of hanging gardens, 

which provide habitat for threatened and endangered 

species. 

Geoindicators with Significant Human Influences 

Desert Surface Crusts and Fissures 

The human- caused impact on surface crusts and fissures 

(biological and physical crusts) has been intense in the 

some of the canyon areas of the park. For example, 

starting in the 1930s, a herd of bison (up to 60 head) 

grazed throughout the canyon areas and disturbed some 

areas of soil crusts; this practice ended in the 1980s. The 

herd was an attempt by John Otto to encourage visitors 

to come to Colorado National Monument. In addition, 

damage of crusts occurred in Civilian Conservation 

Corps (CCC) camps and along major trail corridors. 

Slope Failure 

Slope failure, including rockfalls, is a natural process that 

has been exacerbated by human impacts, such as the 

construction of the Rim Rock Drive and by vibration 

from heavy vehicles (e.g., trucks, tour buses, and school 

buses). 

Soil and Sediment Erosion 

Erosion is a fundamental and complex natural process 

that is strongly modified by human activities. Human 

influences on soil and sediment erosion in Colorado 

National Monument occur on a local- scale, the primary 

influence being Rim Rock Drive (e.g., road cuts and 

increased runoff). The proliferation of social trails, 

which is tied to increasing visitation, also causes erosion 

on local- scale (e.g., in Monument Canyon, lower Liberty 

Cap trail, No Thoroughfare Canyon, trail between 

Visitor Center and Book Cliffs View, and Alcove Trail). 

Wetlands Extent, Structure, and Hydrology 

A significant human influence on wetlands in the park 

has been the Fruita pipeline, which leaked and created 

artificial habitats ideal for exotic plants. Additionally, 

two reservoirs were constructed to provide water to the 

citizens of Fruita. These are no longer in use, but future 
 COLM Geologic Resource Evaluation Report 35

demand could cause them to be restored, which is a 

concern for park management. In addition, the CCCcamp members dammed the spring in Monument 

Canyon, and present- day trails pass through wetlands in 

canyon areas. 

Geoindicators with Management Significance 

Desert Surface Crusts and Fissures 

Park management recognizes that biological and physical 

crusts are a unique and fragile resource. An inventory of 

locations is needed in order for park management to plan 

for the proper placement of trails and for the purposes of 

visitor education. 

Groundwater Level 

Groundwater level has high management significance 

because a decrease in groundwater level could have a 

direct effect on the park's seeps and springs, which are 

important resources. Quantifying groundwater level is 

important for management because this information 

could be used for planning and future decision making as 

it relates to development outside of the park's boundary 

(e.g., in Glade Park). 

Groundwater Quality 

Changes in groundwater chemistry could affect 

organisms at seeps and springs. Although the risk of 

contamination is probably not high at present, this could 

change in the next 50 to 100 years. As Glade Park grows, 

the chances of groundwater contamination will increase. 

The risk also depends on the kinds of changes that may 

take place in land use and water use in the recharge area, 

as some changes will pose more serious threats than 

others. 

Slope Failure 

Slope failure happens continuously throughout the park 

and is a constant maintenance issue along Rim Rock 

Drive. Rim Rock Drive is an important park resource, 

which facilitates public enjoyment and the ability to view 

the park. Slope failure is a concern for park management, 

particularly with respect to potential road failure. 

Rockfalls are also a concern of park managers for 

reasons of visitor safety, especially along Rim Rock Drive 

and at overlooks. 

Stream Channel Morphology, Streamflow, Stream 

Sediment Storage and Load 

These three geoindicators are active components of flash 

floods, which are of primary management significance 

and affect all park divisions/units (e.g., maintenance, 

interpretation, resource management). Flash floods are 

the principal agent that form and modify the canyons, as 

well as being a concern for homeowners. Park staff has a 

role to fill as public educators regarding flash floods. 

Park managers recognize the significance of flash floods 

to the park's ecosystem. They also recognize the 

importance of educating homebuilders and homeowners 

about the long history of flash flooding in the area and 

making responsible decisions with respect to the location 

of homes. 

Wetlands 

If more water is needed in Fruita in the future, 

management has concerns that the old water line would 

be reactivated. Intense damage to park resources, 

associated with required reconstruction activities, would 

accompany reactivation of the water line. 

Summary of Recommendations 

The summary includes recommendations for inventory, 

monitoring, and research studies, as well as 

recommendations for public education and park 

planning. Recommendations are not listed in any order 

of priority. 

Recommendations for Inventory and Monitoring 

1. Identify areas with high potential for slope failure 

An inventory of areas along the Rim Rock Drive and 

overlooks with high potential for slope failure would 

have value for inventory, monitoring, and planning. High 

potential areas could be identified with GPS and 

incorporated into the park's GIS. Such an inventory 

would enable park managers to focus on particular areas, 

rather than 23 miles of road. Rangers who regularly drive 

on the road could assist with the process by identifying 

cracks in the asphalt and entering those data into a GPS 

unit, which could be incorporated into GIS. A yearly 

monitoring day could be set aside to revisit and evaluate 

these areas. 

Another simple monitoring technique is to place stakes 

in landslide material along the road to detect 

movement/creep. A survey of these areas could be 

performed once every two years. This is a low- cost 

project that would provide valuable information to park 

managers. 

Once inventories of areas with high potential for slope 

failure are incorporated into the park's GIS, park 

managers will have a valuable planning tool that could be 

used for (1) locating "warning" signs, and (2) coming up 

with options for rerouting the road, if/when it fails. 

2. Gather scientific information on seismicity and 

wind- blown sediments 

Although seismicity and wind- blown sediments are of 

low management significance, having a seismic station 

and wind- blown sediment monitoring station in the 

park would have scientific value and encourage 

collaboration between the park and the local academic 

community. Mesa State College would be interested in 

having one seismic station located in Colorado National 

Monument, possibly in the maintenance or housing area. 

Three stations are needed to get accurate local 

information. Staff at Mesa State College would monitor 

and maintain the station. 

Contact 

• Verner Johnson, vjohnson@mesastate.edu, Mesa State 

Geology Program 
 NPS Geologic Resources Division 36 

Mesa State College needs a used computer to complete 

the seismic station. The NPS Natural Resource Program 

Center may be able to donate a computer. 

Contact 

• Bob Higgins, GRD, Bob_Higgins@nps.gov, 303- 969-

2018. 

In addition, Mesa State College's Geology Program 

would be interested in having a monitoring station for 

wind- blown sediment in Colorado National Monument. 

They would need a collection permit and a sheltered spot 

to place the traps, which they would monitor once per 

year. 

Contact 

• Mesa State College's Geology Program, 

geology@mesastate.edu, 970- 248- 1020 

3. Use geology to identify paleontological and 

archeological sites within the park 

Park managers expressed the desire to use geology as a 

tool for identifying other natural and cultural resources. 

Participants identified some contacts for future studies. 

Paleontological Contacts 

• John Foster, Museum of Western Colorado, 

jfoster@westcomuseum.org, 970- 858- 7282 

• Greg McDonald, Geologic Resources Division, 

Greg_McDonald@nps.gov, 303 - 969- 2821 

Possible Archeology Contact 

• Mesa Verde National Park 

4. Gather baseline data on flash floods 

Repeat photography may be an option for gathering 

baseline information on flash floods. Since floods will 

leave debris, photographing during the event may not be 

necessary. A volunteer could be trained to take photos 

after each flooding event, which occur approximately 

twice per year, typically during July and August. The NPS 

Geoscientist- in- the- Parks (GIP) program may be able 

to provide funding for camera equipment. 

Contact 

• Judy Geniac, GIP Program Manager, Geologic 

Resources Division, Judy_Geniac@nps.gov, 303- 969-

2015 

Another possibility would be to install cameras in 

selected drainages (where homes are in the most 

jeopardy) to photo document flooding. 

Contact 

• Paul Vonguerard, 970- 858- 3617, 

pbvongue@mailscogjn.cr.usgs.gov 

5. Include inventory of soil crusts in mapping of 

vegetation 

Biological and physical soil crusts are a unique resource 

in Colorado National Monument and should be 

preserved because of their potential to protect 

underlying fine material from wind erosion; fix 

atmospheric nitrogen for vascular plants; provide carbon 

to the interspaces between vegetation; secrete metals that 

stimulate plant growth; capture dust (i.e., nutrients) on 

their rough, wet surface areas; and decrease surface 

albedo. 

Depending on soil characteristics, biological crusts may 

increase or reduce the rate of water infiltration. By 

increasing surface roughness, they reduce runoff, thus 

increasing infiltration and the amount of water stored for 

plant use. It is recommended that locations of these 

crusts be identified and incorporated into the park's GIS 

in order to protect and preserve soil crusts. An inventory 

of crusts would enable park managers to plan the 

placement of trails accordingly and educate visitors 

appropriately. Locations of these crusts should also be 

linked to the fire management plan, since the greatest 

amount of crusts occurs where there is the greatest 

amount of piñon and juniper. Future plans for 

operations related to prescribed burns or mechanical 

fuel reduction could have a negative impact on soil 

crusts. 

Contacts 

• Eric Aiello, Eric_Aiello@nps.gov, 970- 242- 7385 

• Jayne Belnap, U.S. Geological Survey in Moab, 435-

719- 2333, jayne_belnap@usgs.gov 

6. Identify baseline level of groundwater and 

periodically monitor 

Baseline data are needed in order to detect groundwater 

depletion caused by increased development in areas 

bordering Colorado National Monument, such as Glade 

Park. Groundwater is a valuable resource for the park's 

seeps and springs, and increased extraction could have a 

negative effect on these valuable resources, as well as on 

the organisms that rely on them. 

Potential sources of data 

• Rocky Mountain Drilling, Glade Park, 970- 434- 8554 

• Dennis Karns, Ute Construction, 970- 243- 2469 

References 

Lohman, S.W., 1965, Geology and artesian water supply 

of the Grand Junction area, Colorado: U.S. Geological 

Survey Professional Paper 451, 149p. 

Lohman, S.W., 1963, Geologic map of the Grand Junction 

area, Colorado: U.S. Geological Survey Miscellaneous 

Geologic Investigations Map I- 404, scale 1:31,680. 

Upon determining a baseline of groundwater level, it is 

recommended that park managers perform periodic 

monitoring. At a minimum a network of wells should be 

monitored at least annually but preferably quarterly or 

more often. Since the park does not have a monitoring 

well, one option would be for park managers to attain 
 COLM Geologic Resource Evaluation Report 37

permission from homeowners in Glade Park to monitor 

water level in private wells. The U.S. Geological Survey 

has capabilities to advise or participate in this activity. 

Another important issue would be to identify the 

groundwater recharge area for Colorado National 

Monument. Determining the rate of groundwater 

withdrawal in the recharge area will be an important step 

in understanding outside development on groundwater 

resources of Colorado National Monument. 

Contact 

• Paul Vonguerard, 970- 858-

3617,pbvongue@mailscogjn.cr.usgs.gov 

7. Identify baseline for groundwater quality and 

periodically monitor 

This baseline should include water chemistry at seeps 

and springs, and at selected wells in Glade Park. Changes 

in land use and water may pose threats to groundwater 

quality. 

8. Inventory wetlands 

Park managers in Colorado National Monument have 

some information about wetlands in the park because of 

the survey of tamarisk that was conducted. To date, two 

wetland areas have been identified (e.g., upper Ute 

Canyon and upper No Thoroughfare Canyon), with a 

total of about 20 acres. Wetlands in the park will be 

inventoried through the vegetation mapping program 

using GIS. Locations of all wetlands need to be mapped, 

ground truthed, and digitized. 

Reference 

Cowardian, L.M, Carter, V., Golet, F.C., and LaRoe,E.T., 

1979, Classification of wetlands and deepwater habitats 

of the United States: U.S. Department of the Interior, 

Fish and Wildlife Service, FWS/OBS- 79/31. 

9. Work with soil scientist to better understand soil 

quality 

Upon review of this scoping report, it was the opinion of 

a soil science expert that some of the observations made 

during the scoping session regarding soil quality were 

incorrect. It is recommended that soil quality of 

Colorado National Monument be revisited, and 

correction and clarification made prior to making 

management decisions. 

Contact 

• Pete Biggam, 303- 987- 6948,pete_biggam@nps.gov 

Recommendations for Research 

1. Create a flash flood model 

Create a flash flood model and run for each drainage in 

Colorado National Monument. This could be a GIP 

project. Park managers could work with local professors 

at Mesa State College (geomorphology, hydrology, and 

GIS). In order to verify the model, data collection is 

needed that measures peak flow drainages in Colorado 

National Monument. 

Installation of crest- stage gages and the rating of stream 

channels using the step- backwater method would 

provide the basic data needed to support flash - flood 

models. The U.S. Geological Survey may be able to 

participate. 

Contacts 

• Judy Geniac, GIP Program Manager, Geologic 

Resources Division, Judy_Geniac@nps.gov, 303- 969-

2015 

• Paul Vonguerard, 970- 858- 3617, 

pbvongue@mailscogjn.cr.usgs.gov 

2. Consider integrated research proposal to examine 

valley fill 

This proposal could provide valuable information to 

park managers regarding rates of erosion, past climate 

change, and sources of sediment. 

3. Put seeps and springs inventory into digital format 

Currently park staff has hand- drawn maps seeps and 

springs on 7.5- minute topographic maps. These data are 

assumed to have been collected at the same time as a 

vegetation study in 1984. Eric Aiello, park Cartographic 

Aid and student at Mesa State College, has been making a 

3D model of the park. He has acquired software to do 

some analysis on watersheds in Colorado National 

Monument. Participants thought that this project is a 

prime candidate for Geoscientist- in- the- Park (GIP) 

funding and encourage park managers to submit a GIP 

proposal. 

Contact 

• Judy Geniac, GIP Program Manager, Geologic 

Resources Division, Judy_Geniac@nps.gov, 303- 969-

2015. 

Recommendation for Public Education 

Develop a plan for educating the public about flash 

floods 

It is recommended that park staff collaborate with the 

U.S. Geological Survey, Colorado Geological Survey, 

and/or local geologists to develop a long- term plan for 

educating the public about flash floods. The plan could 

be modeled after the fire community's efforts, which has 

been successful. A possible "kickoff" event may be to 

host a public field trip that highlights the long history of 

flash floods in the area. The trip could commemorate the 

25th anniversary of the large flash flood that occurred in 

September 1978. The local community, including County 

Commissioners, should be invited. 

Recommendation for Park Planning 

Develop a long- term plan for road failure 

The park has a short- term plan for closure of Rim Rock 

Drive but not a long- term plan, if large sections of the 

road are destroyed. Recent history shows that a road 

closure is a reality, e.g., Rim Rock Drive was closed for 

one year when the area between the two tunnels was 

washed out. A long- term plan for road closure, 

rerouting, maintenance, etc. needs to be part of general 
 NPS Geologic Resources Division 38 

management plan (GMP). It is recommended that park 

staff work with geologists, engineers, and the Federal 

Highway Administration to plan alternatives. The plan 

for rerouting the road should take into consideration the 

geologic strata, location of facilities, and wilderness. In 

addition, fire plays a role in (and could indirectly trigger) 

landslides; therefore, slope failure should be part of the 

Fire Management Plan. The potential to mitigate 

landslides with smaller, prescribed burns should be 

considered. 

Participants 

Colorado National Monument 

Eric Aiello, Cartographic Aid 

Don Baars, Geologist/Volunteer- in- the- Park 

Bill Hood, Geoscientist- in- the- Park/Volunteer- inthe- Park 

Pete Larson, Park Ranger 

Dave Price, Chief of Resource Management 

Ron Young, Supervisory Park Ranger 

Palma Wilson, Superintendent 

National Park Service 

Pete Biggam, Natural Resources Information Division 

(review of soil quality geoindicator only) 

Sid Covington, Geologic Resources Division 

Bob Higgins, Geologic Resources Division 

Greg McDonald, Geologic Resources Division 

Suzy Stutzman, Intermountain Region Support Office 

Other Participants 

Katie KellerLynn, Geologist/NPS Contractor 

Paul Vonguerard, Subdistrict Chief, U.S. Geological 

Survey Water Resource Division 

Tom Wylie, Natural Resource Consultant, General 

Management Plan Team Member
 COLM Geologic Resource Evaluation Report 39

Geoindicators Table for Colorado National Monument 

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. 

Colorado National Monument 

Geologic Resource Evaluation Report 

Natural Resource Report NPS/NRPC/GRD/NRR—2006/007 

NPS D-86, 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 • Katie KellerLynn

Editing • Sid Covington 

Digital Map Production • Stephanie O’Meara and USGS 

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 

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National Park Service 

U.S. Department of the Interior