Colorado National Monument - Geology

To many, the most outstanding natural features of Colorado National Monument are the park's geologic formations. In each of the canyons, visitors can see the remarkable effects of millions of years of erosion on a landscape of sedimentary rock.

The Colorado National Monument is located within the Canyon Lands Basin of the Colorado Plateau physiographic province (SCS 1978). Landscapes are characterized by exposures of colorful, gently dipping sediments that have been differentially eroded to form high plateaus, bold escarpments, and deep canyons. Sandstone monoliths and steep walled canyons sculpted from years of natural erosion provide scenic, educational, and scientific benefits to visitors.

The Rock Fall of ’00 What happened? At about 9:45 in the morning on January 8, 2000, a section of cliff suddenly dropped onto Rim Rock Drive near the Liberty Cap trailhead, completely blocking the roadway. There were no injuries, but because the area was considered unstable, it was cordoned off to the public. Rim Rock Drive remained closed until the rock debris was cleared off and the road repaired.

What fell? The rocks that fell are sandstones that were originally deposited about 140 million years ago by ancient streams. Geologists describe the rocks as being from the Salt Wash Member of the Morrison Formation. Why did they fall? The salt wash sandstone has a distinct layer of soft shale in the middle and a layer of easily eroded shales and sandstones below. Ancient earth movements have created two distinct sets of nearly vertical fractures in the salt wash sandstone.

These two fracture planes meet at nearly right angles, creating large rectangular blocks that are not firmly connected to the rest of the cliff. This lack of a firm connection to adjacent rocks, coupled with the layers of weak shale, means salt wash sandstone is easily eroded in this area of the monument. Has this happened before? Certainly. Our earth is a dynamic and ever-changing place. The rock fall of January 8, 2000 is simply a continuation of the erosion that has carved the canyons of Colorado National Monument. Erosion is a natural process, and in fact is the architect of the spectacular landscape.

Examples of erosion abound within the monument in the form of already-fallen boulders, small rock falls, and stream scouring and widening during flash floods. While larger rock falls occur frequently in geologic time, it is a rare and exciting opportunity to see and study one during our lifetime.

Some of these broken rocks last saw the light of day 140 million years ago when they were laid down in a streambed during the time of the dinosaurs. As geologists study them today they may reveal more about those ancient times, or they might help us understand how we may in the future predict the likelihood of future rock falls.

Geologists, engineers, and historians examined the rock fall and attempted to determine several things: - was there any immediate danger of further rock falls? - was it safe to work in the area with heavy equipment? - how much damage was done to Rim Rock Drive? - how to proceed with the clean up and repair minimizing the effect on Rim Rock Drive, which is a listed structure on the National Register of Historic Places? Considering all of these factors, Rim Rock Drive was cleared and repaired as quickly as possible.

Colorado National Monument - Wildlife

Colorado National Monument's varied terrain attracts many animals to live, nest, or hunt within its boundaries. Among mammals, the mule deer are the largest commonly sighted by visitors. However, coyotes, mountain lions, bobcats, and desert bighorn sheep are also occasionally seen by a lucky visitor. Smaller mammals like foxes, desert cottontails, squirrels, and other rodents are often seen scampering off the sides of the Rim Rock Drive or hiking trails.

The towering walls of the various canyons in the monument are a perfect place for various raptors and songbirds to raise their young. Golden eagles, red-tailed hawks, and turkey vultures often soar aloft on the air currents, Gambel's quail scurry across the trails, and the calls of the mourning dove and the canyon wren echo in the canyons. The various overlooks are excellent places to watch the acrobatics of the white-throated swift just below the rim. Bright blue scrub jays are a common and colorful sight throughout the monument.

Reptiles are generally seen in the monument from early March to late October. They are most visible in May and June, and are active on warm, sunny days and mild evenings. Watch for yellow-headed collared lizards or the plateau whiptail, especially during late morning or late afternoon hours; they often are seen sunning themselves on the warm rocks. Snakes do exist in the monument, but only one, the midget-faded rattlesnake, is poisonous and is rarely seen.

Following summer thunderstorms, listen for calls of frogs or toads in the canyons. Amazingly, there are several species of amphibians that thrive despite the monument’s semiarid environment. Their ability to burrow underground and remain dormant for brief or extended periods of time gives them a high tolerance to temperature extremes and drought. Following heavy rains, several species, like the red-spotted toad or the canyon tree frog, surface to take advantage of seasonal water sources. As most of the species are primarily nocturnal and well camouflaged, they are rarely seen, but if you listen, you may hear them calling late in the evening.

MAMMALS

Most of the mammals that live in Colorado National Monument on a year-round basis have evolved unique physical and behavioral adaptations to survive in this semiarid ecosystem. Annual precipitation at Colorado National Monument is less than 12 inches a year with summer temperatures ranging from the high 90s to over 110 degrees in the canyons. Winters are generally mild with lows occasionally dropping to the single digits. These extremes, combined with a minimal amount of water, can prove to be challenging to the wildlife that make this their home.

A majority of mammals like the desert cottontail, mule deer, coyote, porcupine, jackrabbit, and many songbird species are crepuscular, meaning they are only active in the early morning hours or late in the evening when temperatures are cooler and there is just enough light to forage for food.

Others, like the ringtail, fox, bobcat, mountian lion, several species of bats, and a variety of small desert rodents, are nocturnal, emerging at night and are rarely seen.

Mammals like rock squirrels, antelope squirrels, and chipmunks are active during the daytime or "diurnal" and are a common sight. Of course there is the occasional rare and exciting report of a mountain lion wandering in one of the canyons or, as was the case in the summer of 1997, a black bear sleeping in Window Rock!

Over 40 species of mammals have been recorded within the boundaries of the monument; however, not all are year round residents. The desert bighorn sheep are frequently seen near the Balanced Rock area on the west side of the park. Elk have also been known to travel down to the monument from the higher elevations during the winter months.

Common Mammals in the Monument

Coyote (Canis latrans) – These medium-sized members of the canid family are commonplace in the American West. Coyotes average about 15 inches in height (at the shoulder) and weigh about 40 pounds. They are primarily nocturnal, but they can sometimes be spotted roaming in daytime. They will eat almost anything, but small rodents and rabbits typically comprise the bulk of their diets. Coyotes breed in the winter and typically give birth to five to ten pups in early spring. This inquisitive and opportunistic animal is the best runner of the canids, reaching speeds up to 30 mph. They are able to leap up to 14 feet in a single bound.

Grey Fox (Urocyon cinereoargenteus) – The grey fox ranges through most of the southern half of North America. These small members of the canid family resemble small dogs with bushy tails. Grey foxes are solitary hunters and eat a wide variety of food, including rabbits, voles, mice, and birds; they also supplement their diets with fruits when they are available. Grey foxes are unique among canids in that they are able to climb trees. They have strong, hooked claws that allow them to scramble up trees to avoid predators or to get fruit. Grey foxes are nocturnal and den during the day in hollow trees, stumps, or old burrows.

Ringtail (Bassariscus astutus) – This cat-sized carnivore resembles a small fox with a long raccoon-like tail. Its tail is typically as long as its body and is banded with 14 to 16 alternating black and white rings. Ringtails live in a variety of habitats, but have a preference for rocky areas, canyon walls, and talus slopes. They are expert climbers, capable of climbing vertical walls. Ringtails are nocturnal and spend most of the day asleep in dens, typically in rock crevices and hollows. They eat a wide variety of animals, including small mammals, birds, reptiles, amphibians, and insects, but they also supplement their diets with fruit, including juniper berries, in winter.

Rabbits and Hares (family Leporidae) – Worldwide, there are almost 50 species of rabbits and hares, most of which are native to North America. At Colorado National Monument, cottontail rabbits and jack “rabbits” (they are actually hares) are common. They are generally grazers, feeding on grasses and other plants, but they may also feed on twigs and tree bark. While these two groups of mammals are often confused, they are actually quite easy to identify. Rabbits are generally smaller and have relatively smaller ears. Hares have very large ears and long hind legs. Typically, rabbits are weak runners, and when threatened, they often scamper into thick brush. Hares, on the other hand, are more adapted to open country, are very strong runners, and usually burst into bounding runs when threatened. Both groups have high reproductive rates; their litters typically consist of up to eight young, and can be as large as 15.

Prairie Dog (Cynomys ludovicianus) – Prairie dogs, while common on the plains and plateaus of the western U.S., are rare in Colorado National Monument. These small, ground-dwelling rodents are closely related to marmots and ground squirrels, and grow to about 15 inches in length. Prairie dogs are highly social and live in “towns”, sometimes comprised of thousands of individuals. They are named for their bark-like yips that serve as warning cries. Prairie dogs live in holes dug into the ground, sometimes 10-15 feet deep. They collect the dirt removed from their burrows and construct raised hills around the entrance holes to prevent flooding. They are active during the day, and they spend most of their time grooming each other and defending family territorial boundaries. They eat herbs and grasses that grow within range of their burrows.

Porcupine (Erethizon dorsatum) – These large members of the rodent family have long, pointed spines, or quills, growing from their backs and sides. The quills have needle-sharp ends and hundreds of barbs. They are loosely attached and can be raised by the muscles of the skin. Porcupines can be found in wooded areas throughout North America, from Alaska to Mexico. They are herbivorous, and often eat the bark of trees. They grow to a length of about 26 inches, and have short tails and brownish hair that almost conceals their two to six inch quills.

Bobcat (Lynx rufus) – These medium-sized cats live in shrubby country and broken forests and are fairly common in the monument. Bobcats are about 25-30 inches in height (at the shoulder), and can weigh up to 60 pounds. They are gray-brown with distinctive black spots, and have short “bobbed” tails that are about four inches long. Bobcats are skilled predators, and their prey include rodents, rabbits, hares, squirrels, and birds. They are excellent climbers and often wait in trees to pounce on their prey. Bobcats are territorial, and they mark their territories with urine, scent from anal glands, and feces deposited on the ground during their frequent territory patrols. Bobcats often wander large distances, sometimes 25-50 miles, but normally stay within a few miles of their territories. The territories of males are larger than those of females. While bobcats are solitary in nature, the two sexes do remain together briefly during the breeding season, and it is not unusual for the male to help provide food for the kittens. They usually mate in late winter and kittens are born in early spring. The kittens weigh less than one pound at birth and are blind and completely helpless. They normally venture from their dens at the age of five weeks, and by nine months, are nearly independent.

Mountain Lion (Felis concolor) – Mountain lions, also commonly known as cougars and pumas, range from northern Canada to the tip of South America. They are large, powerful cats, standing 28 inches (at the shoulder) and weighing up to 200 pounds. Despite their large size, they are very quick and agile; mountain lions can cover up to 23 feet in a single leap. However, because they tire quickly, they must be accurate; if prey is able to survive initial attack, it will normally escape. They generally hunt in the daytime by stalking and pouncing on the back of their fleeing prey. Once they power their prey to the ground, they normally deliver a fatal bite to the back of the neck. Their principle food source is deer. Mountain lions have very large territories that rarely overlap. On the unlikely chance that two of these solitary cats meet, they rarely fight to defend their own territories. During the breeding season, male and female mountain lions hunt together and sleep next to each other. The female gives birth to cubs in a well hidden den, usually between rocks or in a cave. The cubs are spotted at birth, and they lose these spots at about six months of age. Although they can hunt for themselves at nine months of age, they normally stay with their mothers for two years. There are many tales of the savagery of mountain lions, and their attacks on people, but unprovoked attacks are very rare. They usually avoid contact with humans, but if cornered, they can be very dangerous, and should be treated with respect and caution.

Desert Bighorn (ovis canadensis nelsoni) - Desert bighorn sheep are among the most intriguing mammals of canyon country. They are wary of human contact and blend so well into the terrain they inhabit that sightings are a special event. Once in danger of becoming extinct, the desert bighorn are making a tentative comeback in southeast Utah due to a comprehensive reintroduction effort by the National Park Service. With one of the few remaining native herds, Colorado National Monument has been a critical area for restoration efforts.

Desert or Nelson’s bighorn sheep are considered by most biologists to be a unique subspecies. Unlike their Rocky Mountain cousins, desert bighorn have adapted to hot, dry climates, and have longer legs, lighter coats and smaller bodies. Bighorn sheep are common in American Indian rock art, an indication of their presence and prominence in indigenous cultures.

Accounts from European explorers in the late 1600s estimate that more than two million desert bighorn once roamed the southwest. However, by the late 1800s bighorn sheep had disappeared or declined in many areas. Extremely vulnerable to diseases from European livestock, herd after herd of wild sheep were decimated by pathogens like scabies (an ear mite) and anthrax (a bacterial disease) introduced by domestic sheep. Bighorns were also killed by early explorers, settlers, and trophy hunters.

Increased human activity, competition with domesticated cattle and sheep for food and development are the biggest threats to the desert bighorn sheep today. For remaining herds to survive, intensive management and conservation measures may be necessary. Present and future protection of undeveloped land and wilderness areas are key to the species' survival.

REPTILES

Reptiles are among the most conspicuous animals found in the monument and are seen from early March through late October, being most active in May and June. According to the latest survey conducted, nine species of lizards were identified as monument residents.

Lizards are most active on warm, sunny days and temperate evenings, and are commonly seen sunbathing on rock exposures throughout the park. In colder temperatures they hibernate, relying on food stored as fat in their tails for nutrition.

Nine species of snakes have been identified in the monument but because they are most active at night, they are rarely seen. The midget-faded rattlesnake, a subspecies of the western rattlesnake, is the only poisonous snake found in the monument. This snake, like all other snakes found here, is not aggressive and avoids human contact.

BIRDS

When visiting Colorado National Monument, take the opportunity to enjoy the abundant bird life that surrounds you. Listen, you might hear the laughing call of a raven or the mellow whistle of a Say’s phoebe. You might see a Gambel’s quail scurry across a trail or witness a turkey vulture wobble on an air current high above.

The pinyon-juniper woodland that dominates most of this area provides an essential habitat for a wide diversity of birds. At least 54 breeding songbird species and nine breeding species of raptors have been identified in the monument. Several other species are known to pass through during migration and winter months. Recognizing the significance of this area, Colorado National Monument was designated as an important bird area (IBA) by the National Audubon Society and the American Bird Conservatory on May 10, 2000.

INSECTS

Insects are everywhere in Colorado National Monument. But depending on the season, the elevation, the weather, and even the time of day, visitors may see hundreds or only a few insects.

At lower elevations and in the canyon bottoms, insect numbers and diversity are highest in spring when the desert flowers bloom. A wet spring will have not only more flowers but many more insects than a dry one. Another peak in numbers is reached in early fall when the rabbitbrush puts forth its many golden flowers. In the pinyon-juniper forest, insect numbers gradually increase and probably reach their peak in late summer.

Some insects, like moths, tend to be common throughout the warm months; while others, like the May and June Beetles, or some of the butterflies are found for only a few weeks in the spring.

The weather plays a large role either in controlling insect numbers or having the opposite effect and allowing their numbers to explode. Many insects will survive a warm winter, but be killed in a very cold one. Summer rains that soften the hard ground and make it easier to dig tunnels often cause the ant colonies to swarm and thousands of winged queens and drones take to the air to start new colonies.

For the visitor who takes the time to stop, look closely, and listen, there are always some insects or other wildlife to be seen or heard.

AMPHIBIANS

The semiarid environment of the Colorado National Monument may seem like an unusual place to find amphibians, but in fact, there are several species of frogs, toads, and a rarely seen salamander that reside in the monument. Some amphibians have the ability to remain dormant in underground burrows, sometimes for more than a year, enabling them to survive in harsh, dry environments. Emerging from their burrows during the rainy season they take advantage of intermittent streams and potholes. The raucous vocalizations heard, usually in the late spring and summer evenings, are emitted by male toads and frogs trying to attract mates and quickly reproduce while conditions are optimal.

Amphibians are very sensitive to their terrestrial and aquatic environments, changes in either can effect their survival and propagation. Like the “canary in a coal mine”, amphibians are considered indicator species that serve as monitors of the environment. Over the last several years scientists have documented an alarming decline in amphibian populations, some to the point of extinction. While a specific reason for this trend is unknown, there are several possibilities being studied. Pollution, acid rain, global warming, loss of habitat, and non-native predators / competitors are just a few of the changes that may be causing the declining populations.

Amphibian populations within Colorado National Monument are greatest along small perennial streams found in No Thoroughfare and Ute Canyons. Visitors can help amphibians by not disturbing water resources and reporting sightings at the visitor center.

Colorado National Monument - Ecology

Vegetation within the monument and surrounding lands is primarily pinyon-juniper woodland, which receives less than 12 inches (28 cm) average annual precipitation. Woodland trees are usually less than 20 to 30 feet tall (6 to 9 m). Shrubs associated with this woodland include rabbitbrush, big sagebrush, single-leaf ash, broom snakeweed, Utah serviceberry, yucca, Mormon tea, mountain mahogany and cliff rose among others.

Cacti And Desert Succculents

Colorado National Monument sits on the eastern edge of the Great Basin Desert. Unlike the more familiar deserts farther south, the hot arid summers in the Great Basin give way to freezing cold winter conditions. This presents some special challenges to the survival of succulent plants such as cacti.

Succulent plants have evolved the ability to quickly store water in specialized spongy tissues whenever moisture becomes available for use later in times of drought. This ability to store water can, however, create a serious plant survival problem during freezing cold weather. Moisture within the succulent plant tissues freezes, causing severe damage or death to the plant.

As winter approaches, cacti of the Great Basin Desert are able to reduce the moisture in their tissues to the point that they shrivel and go limp; some actually shrink down into the soil. The moisture remaining in the plant is altered so that the succulent plant tissues are not injured by freezing.

The return of spring warmth and moisture is all that's necessary for these cold climate cacti to quickly and fully recover from winter dormancy.

Cacti are the most abundant type of succulent plant within Colorado National Monument.

Visitors may find the following species:

Missouri Pincushion (Escobaria missouriensis)

Porcupine Prickly Pear (Opuntia erinacea)

Brittle Cactus (Opuntia fragilis)

Purple-Fruited Prickly Pear (Opuntia phaeacantha)

Cliff Prickly Pear (Opuntia rhodantha)

Mountain Ball Cactus (Pediocactus simpsonii)

Eagle Claw (Sclerocactus parviflorus)

Claret Cup Cactus (Echinocereus triglochidiatus)

Spineless Hedgehog Cactus (Echinocereus triglochidiatus forma inermis)

PRICKLY PEAR IN DEPTH

The common prickly pear cactus is one indicator of land health. The area of lowest precipitation with the most easily disturbed soils are along the northeastern boundary (urban interface). The dominant vegetation consists of galleta (Pleuraphis jamesii) - a native grass, prickly pear cactus, and annual weeds. When buffalo were in the monument this area was over-grazed and trampled. With grasses removed the cacti took over making it hard to walk across the ground with out continually stepping on cactus plants. After removal of the buffalo, galleta began to come back. In wetter years this grass grows tall enough to out compete cactus for sunlight. This competition has reduced the cactus to a reasonable distribution.

Prickly pear is an important native plant. It is a protective site for a rodent to burrow under. During drought years they are an important food source for grazing animals. During wetter years the largest species of prickly pear produces a red fruit that is as good and sweet as an apple or pear. This fruit is highly prized by coyotes and a treat for the knowledgeable hiker.

Prickly pear pads are enlarged and have flattened stems. Their function is photosynthesis (energy capture and food production). They also store food and water. The spines grow from the point that produces leaves in other plants. The pads have a wax coating that masks the bright green underneath. The darker green would absorb too much light and cause the plant to cook under intense sunlight on a hot summer day. As the pad dries and shrinks in size during drought, the wax surface wrinkles producing an even duller color. During dry periods some pads take on a reddish color which protects the plant from ultra violet light. Stems will on the average produce a new pad each year and the pad lives for around ten years. As the old pads die the newer pads can send down roots so the plant can continue mining for nutrients and water.

During late spring and early summer these plants put on a great show. The flowers are large with waxy appearing petals. The flowers can be yellow-green, yellow, bronze, pink or violet.

In the center is one bright green stigma surrounded by hundreds of stamens. The stamens are touch sensitive and curl in on beetles as they forage within the flower. This covers the beetles with pollen that they carry to the next cactus blossom.

TREES AND SHRUBS

The vegetation types in Colorado National Monument are a combination of pinyon pine, juniper, sagebrush, native grasses, desert shrubs, and limited riparian species. A coverage of 75 percent pinyon-juniper dominates the mesa tops with scattered sage-grass meadows. The canyon floors exhibit more of a mixture of pinyon-juniper, sagebrush, and desert shrubs.

Pinyon - Pinyon pine produce large edible seeds thus the scientific name Pinus edulis. Seed production is infrequent in the monument. Winter moisture is ample for the trees to produce male cones for pollen and for female cones to set seed. The summers are usually too dry, thus while the cones have grown, some of the seeds will be aborted. All that is found is a dried up scale in the cone. When there is a crop, squirrels and pinyon jays have a feast.

Pinyon trees are very resinous. During the hottest times of summer the trees dry out. The combination of dry wood and resin makes them very flammable. When they burn they produce very hot and fast moving fires.

Juniper (Juniperus osteosperma)- Junipers produce a cone that is a blue wax covered berry-like structure. These cones are poisonous to most animals and are a rich food source to others such as the cedar waxwing. The older junipers in our park are often infected with mistletoe. Mistletoe is a plant that is parasitic on junipers. It feeds on the tissues just below the bark and eventually kills the tree. Birds eat the sticky mistletoe berries. Berries that stick to the outside of their beak are removed by brushing their bill back and fourth on a tree branch. In doing this they have planted the seed on the limb of another tree.

Older junipers have character with their large twisted and misshapen trunks. The transport tissues on one side of a tree may die shifting all growth and transport of water, nutrients, and sap to the other side of the tree. Other transport tissues die, further distorting the trunk.

Juniper trees can withstand an inch or two less precipitation per year than pine trees. This is why the tree line that extends into desert is of junipers only. The juniper is like the pine in that as it ages, vegetation on the forest floor is greatly reduced. These trees also produce very hot forest fires that can move fast.

Singleleaf ash (Fraxinus anomala) - This is the only native broadleaf tree that grows in our semi-desert climate. It is a dwarf tree that normally is less than 15 feet tall. These trees are found where a little extra water collects. In springs of good moisture they produce an abundance of single winged seeds.

Shrubs - Mesa tops are covered with pinyon-juniper forests that have open areas composed of sagebrush (Artemisia tridentata) with some rabbit brush (Chrysothamnus nauseosus) are known as sage flats. These shrub areas support several native grasses such as galleta (Pleuraphis jamesii),Indian ricegrass (Achnatheram hymenoides), and needle and thread grass (hesperostipa comata). Scattered among this vegetation are small white daisies, orange poppy mallow, and purple vetches.

Above 6,000 feet, steep rocky hillsides are typically covered by mountain mahogany (Cercocarpus montanus), sagebrush, and serviceberry (Amelanchier utahensis) with smaller shade loving snowberry (Symphoricarpos oreophilus) growing under them.

Seasonal drainages can provide a habitat for vegetation more typically seen in riparian zones. Fremont's cottonwood (Populus fremontii), coyote willow (Salix exigua), and tamarisk (Tamarix ramosissima) can be seen in various locations throughout the park but are perhaps most prominent in Ute and No Thoroughfare Canyon.

Scattered cottonwood and coyote willow is the dominant vegetation. Growing under them are sedges, rushes, and scouring rush. In the few places where there are small pools, cattails (Typha domingensis) are found.

Dense shade loving shrubs like mountain mahogany, alder (Alnus incana), wild rose (Rosa woodsii), and Apache plume (Clematis ligusticifolia) vines are common in the box canyons of the monument.

WILDFLOWERS

A wide variety of species await the visitor from the lower sagebrush community, through the pinyon-juniper woodland and up to the oak transition zone. Individual species differ in number each year according to rainfall and weather conditions micro-ecosystems abound as topography offers a wide gamut of growing conditions. Tall south-facing sandstone cliffs offer protection and warmth allowing the opportunity to discover flowering plants year-round. Seep and springs encircled by rock bluffs protect lush fern gardens.

The desert annuals have adapted to the arid environment through a series of different strategies. Many plants, including wildflowers like the hairy goldenaster, have small leaves to reduce the amount of transpiration with "hairs" to interrupt wind flow and shade the leaf's surface. Other flowering plants like the desert four o'clock have developed thick, waxy coverings on the leaves and stems to reduce the amount of water loss.

Flowers bloom during the wetter spring and fall seasons and avoid the summer heat and drought. Using another strategy, some plants like evening primrose, often seen along Rim Rock Drive, bloom during the cooler evenings and nights and are pollinated by night flying insects such as moths.

Soils of Colorado National Monument

Soils within the monument are made up primarily of eolian (wind blown) material, as well as eroded Entrada, Wingate, and Chinle sandstone bedrock. The texture of the soils range from loamy sands (coarse) to sandy clay loams (fine). Soil eroded from the Entrada and Wingate sandstones, the Chinle shale and Precambrian is shallow, sandy and rocky. Clay soils derived from the Morrison Formation and by pedogenic processes (weathering), are found at higher elevations and are very expansive and slippery when wet.

The desert climate allows only sparse growth of desert shrubs and grasses, thus the importance of fragile biological soil crusts (formerly known as cryptobiotic soils) to provide soil stability as well as a nitrogen source for other plants/organisms to utilize. Soils in the monument are highly permeable allowing moisture to be channeled and trapped between rock layers and along fissures contributing to lower elevation springs and seeps.

Colorado National Monument - Contact

Colorado National Monument
Fruita, CO 81521-0001

Visitor Information: 970-858-3617 ext 360

By Fax: 970-858-0372

HOURS OF OPERATION

Colorado National Monument is open 24 hours a day, seven days a week.

Visitor center: Memorial Day to Labor Day: Operating hours are from 8 a.m. until 6 p.m. The bookstore is operated here by the Colorado National Monument Association.

Labor Day to Memorial Day: Operating Hours are from 9 a.m. until 5 p.m.

The visitor center is closed on December 25.

Campground: Saddlehorn campground is open all year.

Colorado National Monument - Directions

By Plane from the Grand Junction Regional Airport: American Airlines, Frontier Airlines, Great Lakes Airlines, United Express/Skywest, Delta Connection/Skywest, US Airways and Allegiant Airlines currently serve the Grand Junction area.

For travelers going Westbound through the Grand Valley: Take Highway I-70 to Grand Junction, and take Exit 31 (Horizon Drive). Follow signs through Grand Junction to the east entrance.

For travelers going Eastbound through the Grand Valley: Take Highway I-70 to Exit 19 (Fruita) and go south on Highway 340 to the west entrance, which is approximately three miles from Fruita. The Visitor Center and Campground are four miles up from the west entrance.

Public Transportation: Tour bus and taxi service is available. Contact the Grand Junction Visitor and Convention Bureau for more information.

Train: Amtrak provides daily service to Grand Junction.

HOURS OF OPERATION

Colorado National Monument is open 24 hours a day, seven days a week.

Visitor center: Memorial Day to Labor Day: Operating hours are from 8 a.m. until 6 p.m. The bookstore is operated here by the Colorado National Monument Association.

Labor Day to Memorial Day: Operating Hours are from 9 a.m. until 5 p.m.

The visitor center is closed on December 25.

Campground: Saddlehorn campground is open all year.