The Colorado National Monument is celebrating its 100th Anniversary in 2011. There are two entrances which connect Rim Rick Drive, that was in large part built with Civilian Conservation Corps (CCC) labor. John Otto (
visit link) championed the preservation of the area as a geologic treasure. The above coordinates are for the West entrance near Fruita, Colorado. The East entrance is near Grand Junction and is at N39° 02.110, W108° 37.866.
"The Colorado Plateau and its desert landscape covers parts of Colorado, Utah, Arizona, and New Mexico, including Utah’s canyonlands and the Grand Canyon. As one heads west, however, this spectacular region has its most visible beginnings on the western Grand Junction skyline in Colorado National Monument (Carpenter, 2002).
Over a period of 1.7 billion years, geologic processes have created the features at Colorado National Monument. These processes include volcanism in island arcs along the growing ancestral North American continental margin, high-grade metamorphism, several periods of mountain-building, several periods of deep erosion, deposition of marine and non-marine sediments, more uplift, and finally erosion that carved the modern landforms (Scott et al., 2001).
Colorado National Monument lies along the northeastern flank of a large topographic feature known as the Uncompahgre Plateau. It is a high, elongated plateau region that extends from Ridgeway, Colorado, northwestward to near Cisco, Utah. The metamorphosed crystalline basement rock (1.7 billion years old), as seen in the monument, underlies the entire length of the plateau, with the Triassic Chinle Formation resting directly on the ancient basement rocks. There is no hint of the existence of any rocks having been deposited on the eroded basement surface between Late 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. Compressive mountain building and intrusion of granitic rock and pegmatite dikes followed. During Cambrian through Mississippian time (545-320 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 here—were eroded, transported, and deposited away from the monument area in great thicknesses into the Paradox Basin. Once again, the highly metamorphosed cores of ancient mountains lay exposed in the monument area.
Then deposition began again. Triassic through Cretaceous sediments were deposited over Colorado, this time under largely non-marine conditions until the Late Cretaceous seas covered the area. During the Mesozoic, non-marine sandstone and shale were deposited on the Precambrian basement rock. Most of the cross-bedded sandstone was deposited in desert conditions, and commonly shale was deposited in shallow non-marine lakes. Then the thick marine Mancos Shale and younger non-marine sandstone and shale covered these strata.
For a third time, mountain building affected Colorado. The Laramide Orogeny began in Late Cretaceous time (about 70 million years ago) and continued into the middle Eocene (about 50 million years ago). This mountain-building episode caused uplift, folding, and faulting in the Colorado Plateau region. Most of the present-day structural framework for Colorado National Monument was formed during the Laramide Orogeny.
After the Laramide Orogeny, during a significant part of the Cenozoic Era, great volumes of sedimentary rocks—particularly the soft, easily eroded shale—were slowly removed 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 is continuing 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. It is the canyon-cutting process that today is creating the magnificent scenery of Colorado National Monument.
photo of Wingate Sandstone
Wingate Sandstone erodes forming steep cliffs.
Colorado National Monument’s magnificent scenery is a result of the process of erosion that creates both its beauty and hazardous conditions. Intense summer thunderstorms are common and quickly produce large volumes of water that rush through the canyons of the monument. These storms erode the canyons, as well as flood buildings and roads built in their paths. Unstable cliffs formed, for example, by the Wingate Sandstone produce rockfalls that pose a threat in areas where visitors travel and that have been destabilized during construction of Rim Rock Drive. Expansive clays, present in rocks in the monument, play a role when wetted, and enhance landslides in the area." (from (
visit link) )
"Colorado National Monument preserves one of the grand landscapes of the American West. But this treasure is much more than a monument. Towering monoliths exist within a vast plateau-and-canyon panorama. You can experience sheer-walled, red rock canyons along the twists and turns of Rim Rock Drive, where you may spy bighorn sheep and soaring eagles." (from (
visit link) )
"Each November, runners come to Colorado National Monument to compete in the 26.2 mile Rim Rock Marathon, a race across the entire length of the monument's Rim Rock Drive. The race is one of the longest through any National Park Service site." (from (
visit link) )
"Colorado National Monument, forming the southwest skyline of Grand Junction, is a spectacular 32-square-mile parkland that preserves several deep sandstone canyons on the northern edge of the Uncompahgre Plateau. The monument, administered by the National Park Service, was established in 1911. Besides its abrupt canyons, Colorado National Monument also offers an assortment of sheer spires including Independence Monument and Sentinel Spire as well as lots of great hiking and sightseeing. The free-standing towers and the vertical canyon walls are composed of Wingate sandstone, a fine-grained formation originally deposited as immense sand dunes during the Triassic Period some 210 million years ago. Their tops are protected by a harder sandstone, the erosion-resistant Kayenta sandstone." (from (
visit link) )
While I was not able to attend any of the Centennial Celebrations, information may be found (
visit link) about the events.
The road is in great condition, but is only two lane widths - no shoulder. There are many bicyclists on the east (southern) side of the monument enjoying the climb and views. Please pass with care (state law!). If you enter from the east gate, you will always be on the road closest to the edge of the canyon. If heights are an issue, you may want to enter on the west gate (at Fruita) and drive closest to the walls of the canyon. There are many pull-offs to park to enjoy the scenery. Camping is available near the Visitor's Center. There is a wonderful museum in the Visitors Center that tells about the history of the monument, the geology and the wildlife.
If you go hiking, please stay on the trails. Dogs are not allowed on the trails. Dogs are allowed in the park, but must always be leashed and their droppings removed. You may not take any natural items (i.e., rocks) from the monument. This stunningly beautiful area is very fragile - please protect it for future visitors.