Theodore Roosevelt once said that the Grand Canyon was the "one great site that every American should see."
Playlist of videos about the canyon.
Grand Canyon attracts the attention of the world for many reasons, but
perhaps its greatest significance lies in the geologic record that is so
beautifully preserved and exposed here. The rocks at Grand Canyon are not
inherently unique; similar rocks are found throughout the world. What is
unique about the geologic record at Grand Canyon is the great variety of
rocks present, the clarity with which they're exposed, and the complex
geologic story they tell.
The South Rim of Grand Canyon lies on the edge of a high plateau whose gray-green forests stand out in sharp contrast to the arid lands below the rim. From here the cliffs drop 5000 feet/1524 m to the Colorado River, crossing several biotic zones in the process. It is a landscape characterized by abundant sunshine, extremes of temperature, and long periods of drought punctuated by torrential downpours in summer and snow in winter. The soil is thin; bedrock lies just a few inches below the surface. The competition for moisture in this dry land is keen.
The forest on the South Rim is open and park-like. At elevations above
7000 feet/2134 m, ponderosa pine is the dominant tree in the forest. Below
7000 feet/2134 m pinyon pine and Utah juniper are the dominant trees.
Gambel oak is another common member of the forest. The trees are
interspersed with drought-resistant shrubs like cliffrose, fernbush, and
serviceberry. Warm, sunny areas along the rim may be home to desert plants
like banana yucca and claretcup cactus.
Below the rim, it's another world. The temperature at the bottom of the
Canyon can be as much as 30 degrees F higher than temperatures on the rim.
Summertime highs along the Colorado River can reach 120 degrees F/49
degrees C. Much of the inner canyon is considered desert, excluding, of
course, the areas along the river and tributary streams with their rich
riparian (streamside) habitat. Much of the vegetation in the inner canyon
is typical of that found in deserts to the south: cacti and
drought-resistant shrubs. Riparian plants include thickets of willow and
The park is home to a wide variety of animals. There are 75 species of mammals, 50 species of reptiles and amphibians, 25 species of fish, and over 300 species of birds at Grand Canyon. Mule deer are common throughout the park and are the mammals most commonly seen on the rim. Desert bighorn inhabit the remote slopes of the inner canyon but are occasionally seen on established trails in the Canyon. Bobcats and coyotes range from rim to river, and a small population of mountain lions exists in the park. Among the smaller mammals that inhabit Grand Canyon are ringtails (closely related to raccoons), beavers, gophers, chipmunks, several varieties of squirrels, rabbits and bats. Reptiles and amphibians are represented by a wide variety of lizards, snakes (including the unique Grand Canyon pink rattlesnake), turtles, frogs, toads and salamanders. Hundreds of species of birds make their home in the park, along with
countless insects and arachnids (spiders).
Grand Canyon National Park is home to a number of threatened or endangered
species. Most notable of these are the native Colorado River fish who have
suffered as a result of the dramatic changes in water volume, temperature
and sediment load of the Colorado River since the completion of Glen
Canyon Dam in 1963. These include the Colorado squawfish, humpback chub,
and bonytail chub. The park is also home to several species of endangered
birds, including the peregrine falcon and bald eagle, and a number of
endangered plants. More and more, protected lands like Grand Canyon
National Park provide a refuge for plants and animals that are under
increasing pressure elsewhere.
- National Park Service (More at http://www.nps.gov/grca/grandcanyon/quicklook/index.htm)