Grand Canyon National Park - Nature & Science (U.S. National Park Service)

The Colorado River in the inner gorge. NPS Photo.

Grand Canyon Geology Introduction - In Depth

Grand Canyon National Park, a World Heritage Site, encompasses 1,218,375 acres and lies on the Colorado Plateau in northwestern Arizona. The land is semi-arid and consists of raised plateaus and structural basins typical of the southwestern United States. Drainage systems have cut deeply through the rock, forming numerous steep-walled canyons. Forests are found at higher elevations while the lower elevations are comprised of a series of desert basins.

Well known for its geologic significance, the Grand Canyon is one of the most studied geologic landscapes in the world. It offers an excellent record of three of the four eras of geological time, a rich and diverse fossil record, a vast array of geologic features and rock types, and numerous caves containing extensive and significant geological, paleontological, archeological and biological resources. It is considered one of the finest examples of arid-land erosion in the world. The Canyon, incised by the Colorado River, is immense, averaging 4,000 feet deep for its entire 277 miles. It is 6,000 feet deep at its deepest point and 15 miles at its widest. However, the significance of Grand Canyon is not limited to its geology.

The Park contains several major ecosystems. Its great biological diversity can be attributed to the presence of five of the seven life zones and three of the four desert types in North America. The five life zones represented are the Lower Sonoran, Upper Sonoran, Transition, Canadian, and Hudsonian. This is equivalent to traveling from Mexico to Canada. The Park also serves as an ecological refuge, with relatively undisturbed remnants of dwindling ecosystems (such as boreal forest and desert riparian communities). It is home to numerous rare, endemic (found only at Grand Canyon), and specially protected (threatened/endangered) plant and animal species. Over 1,500 plant, 355 bird, 89 mammalian, 47 reptile, 9 amphibian, and 17 fish species are found in the park.

Some Quick Links to Special Grand Canyon Topics

Canyon Sketches Vol 02 - April 2008
Volunteers Help Control Invasive Plants
Invasive plants such as Sahara mustard pose a serious ecological threat to Grand Canyon. Volunteers have made important contributions towards controlling this aggressive invader over the last few years. Volunteer trips with Science and Resource Management’s vegetation program are fun and educational and give people who love Grand Canyon the opportunity to help preserve park resources.

Canyon Sketches Vol 05 - August 2008
Park Biologists Conserve Rare Plant
Plant biologists identified several populations of Tusayan flameflower (Phemeranthus validulus) in areas that will be impacted by the construction of parking lots at Canyon View Information Plaza. In order to conserve this rare Grand Canyon species, they recently salvaged plants from construction zones and transplanted them in suitable habitat nearby.

Canyon Sketches eMagazine Home Page

A Biologist’s Biologist: Remembering Eric York
Grand Canyon National Park biologist Eric York unexpectedly passed away in the fall of 2007. Learn about Eric’s research on the park’s mountain lions and share in our remembrance of this great man. Park staff honor Eric each day by carrying on his research, and by sharing his passion for big cats, wildlife and wild places.

Mountain Lion Research at Grand Canyon
In 2003, National Park Service wildlife biologists at Grand Canyon National Park initiated a radiotelemetry study of mountain lions in and around the park. The purpose of this study is to gather information about lion behavior, including predation habits, reproductive activity, habitat selection, and other behaviors.

California Condors at Grand Canyon
Today, the California condor is regarded as one of the rarest birds in the world. By the 1980's fewer than two dozen condors lived in the wild. Grand Canyon National Park has participated in the condor reintroduction program with encouraging results, making the park one of the easiest places to view California Condors...

Exotic Tamarisk Management
Tamarisk reached the Grand Canyon area during the late 1920s and early 1930s, becoming a dominant riparian zone species along the Colorado River in 1963. Learn what the park is doing to control and remove tamarisk in order to allow native vegetation to recover.

Grand Canyon Seeps and Springs Study
The Seeps and Springs Study inventories the biotic characteristics of South Rim springs and establishes a biologic baseline against which changes can be measured. From this data scientists hope to gain an increased understanding of riparian (streamside) habitats and thus protect Grand Canyon's seeps and springs from possible future impacts.

Grand Canyon Natural Sounds
Natural sounds are an important part of Grand Canyon National Park. Rustling winds in the canyons and the rush of waters are the heartbeat and breath of some of our most valuable resources.

Biological Soil Crusts
Soil Crusts retard erosion by wind and water, help retain soil moisture during dry periods, slow evaporation rates, and enhance seedling establishment. These living crusts are extremely fragile and one footprint can set back development for decades.

Learn more about Grand Canyon National Park's World Heritage Site Designation.

Examine a comprehensive Bibliography of Documents related to Grand Canyon National Park