Monument Canyon reveals a variety of natural features and ecosystems.
NPS Photo / N Scarborough
Mature soil crust looks dark and lumpy in the red-orange sands. It takes decades to grow just a few inches tall.
Photo courtesy of USGS Canyonlands Research Station
To many, the most outstanding natural features of Colorado National Monument are the park's geological formations. In each of the canyons, visitors can see the remarkable effects of millions of years of erosion on a landscape of sedimentary rock. Many trails also wander through the pinyon-juniper woodland, where you'll encounter the monument's various tree species and other plants.
Two unusual natural features are common in Colorado National Monument and intrigue both scientists and visitors: biological soil crusts and potholes.
Biological Soil Crust
Have you noticed the bumpy, knobby, and sometimes dark soil along the trails? That’s biological soil crust! Just like a coral reef is formed over time by lots of small organisms living together, soil crust is formed the same way. Moss, lichen, green algae, cyanobacteria (sigh-AN-oh bacteria), and microfungi all work together to hold sand grains in place and create an environment where seeds can grow.
Biological soil crust is extremely slow growing; a single footprint can erase decades of growth. You can help protect biological soil crust by staying on established trails. Don’t bust the crust!
Biological soil crust has gone by many names: cryptogamic soil crust, cryptobiotic soil crust, microbiotic soil crust... The main point is to remember that there's life in these sandy desert soils! Without the growth of these living crusts, the dirt would blow away and there'd be many fewer plants and animals living here.
Many species of tiny critters breed in water-filled solution pits like these.
NPS Photo / N Scarborough
Potholes
Potholes are naturally occurring basins in sandstone that collect rainwater and wind-blown sediment. These potholes harbor organisms that are able to survive long periods of dehydration, and also serve as a breeding ground for many high desert amphibians and insects. These communities are very vulnerable to human impacts, so it's best not to splash in the puddles here.
Colorado National Monument is located on the northeastern edge of the Uncompahgre uplift, an area which has at least two periods of mountain-building or uplift. The monument’s historic Rim Rock Drive provides outstanding views of the red rock canyons below and overlooking the neighboring Grand Valley. The monument contains Precambrian basement rocks which are overlain by Triassic and Jurassic sedimentary rocks.
Pinyon-juniper woodland is the most common forest type in the American Southwest, covering over 40 million hectares (100 million acres) in 10 states, and extending south into Mexico, and north into Idaho, Oregon, and Wyoming.
Locations:Arches National Park, Bighorn Canyon National Recreation Area, Canyonlands National Park, Capitol Reef National Park, Casa Grande Ruins National Monument, Colorado National Monument, Death Valley National Park, Dinosaur National Monument, El Morro National Monument, Glen Canyon National Recreation Area, Grand Canyon National Park, Hovenweep National Monument, John Day Fossil Beds National Monument, Joshua Tree National Park, Katmai National Park & Preserve, Mesa Verde National Park, Natural Bridges National Monument, Petrified Forest National Park, Saguaro National Park, White Sands National Park, Zion National Parkmore »
You’ve heard people say to stay on the trail, but what does it matter in the desert? It’s just dirt... right? Wrong—it's alive! Discover what biological soil crusts are and why they're so important in dry environments.
Locations:Arches National Park, Canyonlands National Park, Capitol Reef National Park, Hovenweep National Monument, Natural Bridges National Monument
Be careful where you step because the dirt is alive! This bumpy, lumpy, crust black soil is called biological soil crust and is made up of living organisms.
Locations:Arches National Park, Canyon de Chelly National Monument, Canyonlands National Park, Capitol Reef National Park, Colorado National Monument, Death Valley National Park, Dinosaur National Monument, El Malpais National Monument, El Morro National Monument, Glen Canyon National Recreation Area, Hovenweep National Monument, Joshua Tree National Park, Mesa Verde National Park, Mojave National Preserve, Natural Bridges National Monument, Navajo National Monument, Petrified Forest National Park, Petroglyph National Monument, Rainbow Bridge National Monument, Saguaro National Park, Walnut Canyon National Monument, Yosemite National Park, Zion National Parkmore »
Offices:Geologic Resources Division
Ever wondered what those dark lines were on the rock walls of canyon country? These black, brown, and red streaks are called desert varnish.
Locations:Arches National Park, Canyonlands National Park, Capitol Reef National Park, Colorado National Monument
A bouquet of tiny arches? A miniature cave system?
Known as honeycomb weathering or "swiss-cheese rock," tafoni (singular: tafone) are small, rounded, smooth-edged openings in a rock surface, most often found in arid or semi-arid deserts.
Locations:Arches National Park, Aztec Ruins National Monument, Bandelier National Monument, Canyon de Chelly National Monument, Canyonlands National Park, Capitol Reef National Park, Chaco Culture National Historical Park, El Malpais National Monument, El Morro National Monument, Glen Canyon National Recreation Area, Grand Canyon National Park, Hovenweep National Monument, Hubbell Trading Post National Historic Site, Mesa Verde National Park, Natural Bridges National Monument, Navajo National Monument, Petrified Forest National Park, Petroglyph National Monument, Rainbow Bridge National Monument, Salinas Pueblo Missions National Monument, Sunset Crater Volcano National Monument, Walnut Canyon National Monument, Wupatki National Monument, Yucca House National Monumentmore »
The Colorado Plateau is centered on the four corners area of the Southwest, and includes much of Arizona, Utah, Colorado, and New Mexico.
Locations:Arches National Park, Aztec Ruins National Monument, Bandelier National Monument, Bryce Canyon National Park, Canyon de Chelly National Monument, Canyonlands National Park, Capitol Reef National Park, Chaco Culture National Historical Park, El Malpais National Monument, El Morro National Monument, Glen Canyon National Recreation Area, Grand Canyon National Park, Hovenweep National Monument, Hubbell Trading Post National Historic Site, Mesa Verde National Park, Natural Bridges National Monument, Navajo National Monument, Petrified Forest National Park, Petroglyph National Monument, Rainbow Bridge National Monument, Salinas Pueblo Missions National Monument, Sunset Crater Volcano National Monument, Walnut Canyon National Monument, Wupatki National Monument, Yucca House National Monumentmore »
Describes the origin, uses, threats to, and conservation of water on the Colorado Plateau.
