The Grand Canyon National Park is located in northern Arizona and encompasses over 1 million acres. It was established as a national park in 1919. The Grand Canyon was carved out over millions of years by the Colorado River and continues to be shaped by the river and weathering processes. It is nearly 280 miles long, up to 18 miles wide and over a mile deep in some areas. The park hosts over 1,500 plant and animal species across its different ecosystems and climate zones, from the canyon bottom to the rim. Over 5 million people visit the park each year to view and experience the natural wonder of the Grand Canyon.

1. http://www.closertonature.com/parks/grand-canyon-national-park.htm
Location: Arizona
Size: 1,217,403 acres
Established: 1919
FAST FACTS
Visitation per year average
5 million people
http://grand-canyon-facts.com/
Grand Canyon size facts:
• The Grand Canyon National Park encompassed 1,218,375 acres on the Colorado
Plateau in northwestern Arizona.
• The Grand Canyon is 277 miles long, up to 18 miles wide and 5000 feet deep.
• The Grand Canyon cuts through the Colorado Plateau that is between 5000 and
9000 feet above sea level.
How the grand Canyon came to be The Grand Canyon:
• The Grand Canyon began forming six million years ago with the beginning
erosion of the Colorado River.
• The Grand Canyon has been created in general because of the downward cutting
of the Colorado River which flows thru the canyon.
• Another factor that has caused the Grand Canyon to form is the Kaibab Plateau

2. (which is the north rim) is about 1200 feet higher then the Coconino Plateau
(which is the southern rim). Water from the northern plateau flows into the
canyon creating stream and eroding the earth, but the stream from the southern
plateau flows in a southern direction away from the north therefore the canyon
never fills with water it just continues to erode.
Life and Ecosystems in the Grand Canyon:
• The Grand Canyon contains several major ecosystems.
• The Grand Canyon hosts five of the seven life zones and three of the four desert
types in North America. If you were to travel from Mexico to Canada you
would see the same five life zones represented in the Grand Canyon.
• The five life zones represented are the Lower Sonoran, Upper Sonoran,
Transition, Canadian, and Hudsonian.
• Over 1,500 plant, 355 bird, 89 mammalian, 47 reptile, 9 amphibian, and 17 fish
species are found in the park.
• Since the entire canyon has little soil there is very little vegetation is seen except
on parts of the rims. The northern rim is partly forested with evergreens. In the
depths of the valley very little grows except desert plants and Spanish bayonet.
Grand Canyon Weather
When visitng the Grand Canyon you can be sure of a few things…the beauty will take
your breathe away, the scenic views will seem unbeileivable and the colors will live in
your mind long after you leave this wonder of the world. One thing are can’t be sure of is
the weather! Because of the location of the Grand Canyon and how remote it is you sure
be prepared for all types of weather. The Grand Canyon does experince all four seasons
and snow in April is not unheard of. Packing the right clothing is very important. During
the summer months it is important to have on a hat, light colored clothing, sunglasses and
lots of sunscreen. The winter months call for hats, biits, gloves and a heavy winter jacket.
In the Summer the weather at the Grand Canyon is better 50-80 degress F on the South
Rim. During July, August and September frequent thunderstorms occur. The inner
canyon, where the river is, temperatures reach just over 100 degress and it is very hot! In
the Spring and Fall the weather chnages very quickly and is not predicatble. The months
of May and October are the driest months and the best months to visit the Grand Canyon.
The Winter at the Canyon can be very cold with lots of snow. The trails are usually icy,
but the roads are plowed.
http://go.grolier.com/ #2
New Book of Knowledge
Grolier

3. How to cite this article:
MLA (Modern Language Association) style:
"Grand Canyon National Park." Reviewed by George W. Carey. The New Book of
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assetid=a2012150-h>.
Chicago Manual of Style:"Grand Canyon National Park." Reviewed by
George W. Carey. The New Book of Knowledge®. Grolier Online
http://nbk.grolier.com/cgi-bin/article?assetid=a2012150-h (accessed April
29, 2010).
APA (American Psychological Association) style:
Grand Canyon National Park. (2010). (G. W. Carey, Rev.). The New Book of
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#2
the Grand Canyon in northern Arizona. The Grand Canyon is a huge gorge cut by the
Colorado River over a period of millions of years.
Each day the river and the forces of weathering combine in a process that continually
widens and deepens the Grand Canyon.
designated a national park in 1919
The Grand Canyon is nearly 280 miles (450 kilometers) long and more than 1 mile
(almost 2 kilometers) deep. It varies in width from more than 1 mile to 18 miles (about 2
to 29 kilometers).
Visitors hike and ride mules to the canyon s bottom
They also fish, camp, raft, and take van rides and air tours.
Each rock layer of the Grand Canyon holds a record of geologic history millions of
years old. As the Colorado River cut deeply, forming the gorge, rock surfaces were
exposed. Embedded in these surfaces are fossils. The fossils and the exposed rock layers
give information on how the earth and life on it evolved. The canyon also has several
different climates, stacked one on top of the other. Near the top, where it is coolest, there
are blue spruce and aspen trees. Lower down, there are yellow pines. On the floor of the
canyon, where it is desertlike, the most common plants are cacti.
Reviewed by George W. Carey
Rutgers, The State University of New Jersey

4. #3
Grand Canyon National Park
Grolier Multimedia Ency.
How to cite this article:
MLA (Modern Language Association) style:
"Grand Canyon National Park." Grolier Multimedia Encyclopedia. 2010. Grolier Online.
29 Apr. 2010 <http://gme.grolier.com/article?assetid=0124575-0>.
Chicago Manual of Style:
"Grand Canyon National Park." Grolier Multimedia Encyclopedia. Grolier Online http://
gme.grolier.com/article?assetid=0124575-0 (accessed April 29, 2010).
#3
APA (American Psychological Association) style:
Grand Canyon National Park. (2010). Grolier Multimedia Encyclopedia. Retrieved April
29, 2010, from Grolier Online http://gme.grolier.com/article?assetid=0124575-0
At the highest point along the edge of the canyon, Point Imperial on the North Rim, the
elevation is 2,684 m (8,803 ft)
shelter deer, elks, bears, mountain lions, bobcats, coyotes, squirrels, chipmunks, and a
variety of songbirds
The canyon bottom is a hot, desertlike area where fauna consists mainly of lizards,
snakes, skunks, and the ringtail, or cacomistle, a kind of raccoon; and flora, of agave,
yucca, mesquite, and an assortment of cacti
the canyon wall plunges 1,700 m (5,577 ft) to the river below
The canyon can be viewed in many different ways. There are overlooks at different
points on either rim, and visitors can hike into the canyon along one of the many trails or
take a mule trip into the depths. They can also take a commercially run white water-
rafting trip through the canyon or an airplane or helicopter tour.
#4

5. Grand Canyon
How to Cite This Article
The Grand Canyon, in northwestern Arizona, is a spectacular gorge carved by the
Colorado River into the rocks of the Colorado Plateau. From the Little Colorado River to
Lake Mead, it is 349 km (217 mi) long; of this, 169 km (105 mi) are included in Grand
Canyon National Park. The canyon is more than 1.6 km (1 mi) deep in places and from 6
to 29 km (4 to 18 mi) wide. The North Rim rises to almost 2,740 m (9,000 ft) above sea
level, more than 305 m (1,000 ft) higher than the South Rim. The sedimentary, igneous,
and metamorphic rocks of the canyon represent a vast span of geologic time, from
Precambrian time to the Permian Period, with 2-billion-year-old Vishnu Schist exposed
in the Inner Gorge and 250-million-year-old Kaibab Limestone at the rim.
The canyon itself was excavated in the relatively recent past, over a few million years.
Uplift of the plateau during the Pliocene Epoch forced the ancestral Colorado to deepen
its channel. During the last ice age the climate became cool and wet. Huge lakes formed,
augmenting the flow of the Colorado and its erosive capacity. By the end of the
Pleistocene, the canyon had assumed its modern shape, and the climate began its trend
toward aridity. García López de Cárdenas, a Spanish explorer, discovered the canyon in
1540. Systematic exploration did not begin until the 19th century, when John Wesley
Powell first traveled through the canyon by boat (1869).
Peter Margolin
Further Reading:
Baars, Donald L., A Traveler's Guide to the Geology of the Colorado Plateau (2002).
Beus, Stanley S., and Morales, Michael J., eds., Grand Canyon Geology, 2d ed. (2002).
Childs, Craig, Grand Canyon: Time below the Rim, 2d ed. (2000).
Coder, Christopher M., An Introduction to Grand Canyon Prehistory (2000).
Dolnick, Edward, Down the Great Unknown: John Wesley Powell's 1869 Journey of
Discovery and Tragedy through the Grand Canyon (2001).
Morehouse, Barbara J., A Place Called Grand Canyon: Contested Geographies (1996).
Pyne, Stephen J., How the Canyon Became Grand: A Short History (1998).
Stegner, Page, Grand Canyon: The Great Abyss (2002).
Weir, Bill, Grand Canyon, 2d ed. (2002).

6. How to cite this article:
MLA (Modern Language Association) style:
Margolin, Peter. "Grand Canyon." Grolier Multimedia Encyclopedia. 2010. Grolier
Online. 29 Apr. 2010 <http://gme.grolier.com/article?assetid=0124570-0>.
Chicago Manual of Style:
Margolin, Peter. "Grand Canyon." Grolier Multimedia Encyclopedia. Grolier Online
http://gme.grolier.com/article?assetid=0124570-0 (accessed April 29, 2010).
APA (American Psychological Association) style:
Margolin, P. (2010). Grand Canyon. Grolier Multimedia Encyclopedia. Retrieved April
29, 2010, from Grolier Online http://gme.grolier.com/article?assetid=0124570-
The canyon is more than 1.6 km (1 mi) deep in places and from 6 to 29 km (4 to 18 mi)
wide. The North Rim rises to almost 2,740 m (9,000 ft) above sea level, more than 305 m
(1,000 ft) higher than the South Rim. The sedimentary, igneous, and metamorphic rocks
of the canyon represent a vast span of geologic time, from Precambrian time to the
Permian Period, with 2-billion-year-old Vishnu Schist exposed in the Inner Gorge and
250-million-year-old Kaibab Limestone at the rim.
#5
http://www.nps.gov/grca/
Grand Canyon National Park
P.O. Box 129
Grand Canyon, AZ 86023
April 21, 2010