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Grand Canyon

2007 Schools Wikipedia Selection. Related subjects: North American Geography

   Coordinates: 36°13′38″N, 112°20′7″W

                                    Grand Canyon from the South Rim, 2006.
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                                    Grand Canyon from the South Rim, 2006.

                               Grand Canyon seen from the South Rim, 2003.
                                                                   Enlarge
                               Grand Canyon seen from the South Rim, 2003.

                                       Grand Canyon from the Kaibab Trail.
                                                                   Enlarge
                                       Grand Canyon from the Kaibab Trail.

                               The Grand Canyon, as seen from river-level.
                                                                   Enlarge
                               The Grand Canyon, as seen from river-level.

    Looking down Bright Angel trail to the Grand Canyon. The green area is
      Indian Gardens and the trail continues to Phantom Ranch at the river
                 where a suspension bridge allows access to the North Rim.
                                                                   Enlarge
    Looking down Bright Angel trail to the Grand Canyon. The green area is
      Indian Gardens and the trail continues to Phantom Ranch at the river
                 where a suspension bridge allows access to the North Rim.

   The Grand Canyon is a very colorful, steep-sided gorge, carved by the
   Colorado River, in the U.S. state of Arizona. It is largely contained
   within the Grand Canyon National Park — one of the first national parks
   in the United States. President Theodore Roosevelt was a major
   proponent of the Grand Canyon area, visiting on numerous occasions to
   hunt mountain lions and enjoy the scenery.

   The canyon, created by the Colorado River cutting a channel over
   millions of years, is about 277 miles (446 km) long, ranges in width
   from 0.25 to 15 miles (0.4 to 24 kilometers) and attains a depth of
   more than a mile (1,600 m). Nearly two billion years of the Earth's
   history has been exposed as the Colorado River and its tributaries cut
   through layer after layer of sediment as the Colorado Plateaus have
   uplifted.

   The first recorded sighting of the Grand Canyon by a European was in
   1540, García López de Cárdenas from Spain. The first scientific
   expedition to the canyon was led by U.S. Major John Wesley Powell in
   the late 1860s. Powell referred to the sedimentary rock units exposed
   in the canyon as "leaves in a great story book." Long before that, the
   area was inhabited by Native Americans who built settlements within the
   canyon walls.

Geography

   The Grand Canyon is a very deep - in places over a mile (1600 m) deep -
   277 mile (446 km) long cut in the Colorado Plateau that exposes
   uplifted Proterozoic and Paleozoic strata. The canyon appears on many
   versions of the Seven Natural Wonders of the World list, although none
   of these lists is by any means authoritative. The exposed strata are
   gradually revealed by the gentle incline beginning at Lee's Ferry and
   continuing to Hance Rapid. At the point where the river crosses the
   Grand Wash Fault (near Lake Mead) the Canyon ends.

   Uplift associated with plate tectonics-caused mountain building events
   later moved these sediments thousands of feet upward and created the
   Colorado Plateau. The higher elevation has also resulted in greater
   precipitation in the Colorado River drainage area, but not enough to
   change the Grand Canyon area from being semi-arid. Landslides and other
   mass wasting events then caused headward erosion and stream capture -
   all of which tend to increase the depth and width of canyons in arid
   environments.

   The uplift of the Colorado Plateau is uneven, resulting in the North
   Rim of the Grand Canyon being over a thousand feet (about 300 meters)
   higher than the South Rim. The fact that the Colorado River flows
   closer to the South Rim is also explained by this asymmetrical uplift.
   Almost all runoff from the plateau behind the North Rim (which also
   gets more rain and snow) flows toward the Grand Canyon, while much of
   the runoff on the plateau behind the South Rim flows away from the
   canyon (following the general tilt). The result is much greater erosion
   and thus faster widening of the canyon and its tributary canyons north
   of the Colorado River.

   Temperatures on the North Rim are generally lower than the South Rim
   because of the greater elevation (8000 feet/2438 meters above sea
   level). Heavy snowfall is common during the winter months. Views from
   the North Rim tend to give a better impression of the expanse of the
   canyon than those from the South Rim.

Geology

   The principal consensus among geologists is that the Colorado River
   basin (of which the Grand Canyon is a part) has developed in the past
   40 million years and that the Grand Canyon itself is probably less than
   five to six million years old (with most of the downcutting occurring
   in the last two million years). The result of all this erosion is one
   of the most complete geologic columns on the planet.

   The major geologic exposures in Grand Canyon range in age from the 2
   billion year old Vishnu Schist at the bottom of the Inner Gorge to the
   230 million year old Kaibab Limestone on the Rim. Many of the
   formations were deposited in warm shallow seas, near-shore environments
   (such as beaches), and swamps as the seashore repeatedly advanced and
   retreated over the edge of a proto-North America. Major exceptions
   include the Permian Coconino Sandstone which was laid down as sand
   dunes in a desert and several parts of the Supai Group.

   The great depth of the Grand Canyon and especially the height of its
   strata (most of which formed below sea level) can be attributed to
   5,000 to 10,000 feet (1500 to 3000 m) of uplift of the Colorado
   Plateaus, starting about 65 million years ago (during the Laramide
   Orogeny). This uplift has steepened the stream gradient of the Colorado
   River and its tributaries, which in turn has increased their speed and
   thus their ability to cut through rock (see the elevation summary of
   the Colorado River for present conditions).

   Weather conditions during the ice ages also increased the amount of
   water in the Colorado River drainage system. The ancestral Colorado
   River responded by cutting its channel faster and deeper.

   The base level and course of the Colorado River (or its ancestral
   equivalent) changed 5.3 million years ago when the Gulf of California
   opened and lowered the river's base level (its lowest point). This
   increased the rate of erosion and cut nearly all of the Grand Canyon's
   current depth by 1.2 million years ago. The terraced walls of the
   canyon were created by differential erosion.

   About one million years ago, volcanic activity (mostly near the western
   canyon area) deposited ash and lava over the area, which at times
   completely obstructed the river. These volcanic rocks are the youngest
   in the canyon.

Human history

The Ancestral Puebloans (The Ancient Ones, or Anasazi)

     * The Basketmakers
     * The Pueblo Anasazi
     * Ancient Puebloan Occupation of the Grand Canyon
          + Nankoweap Canyon
          + The Unkar Delta
          + The Bright Angel Site
     * Ancient Pueblo peoples leave the Canyon
          + Beamer's Cabin
               o The Beamers back windo

Other cultures

     * The Cohonina
     * The Sinagua
     * The Pai (The People)
     * The Hualapai (The People of the Pine Trees)
     * The Havasupai (The People of the blue-green water)
     * The Paiutes (The Water People)
     * The Dineh (The People)

European arrival and settlement

The Spanish Explorers

   In September 1540, under orders from the conquistador Francisco Vasquez
   de Coronado to search for the fabled Seven Cities of Cibola, Captain
   Garcia Lopez de Cardenas, along with Hopi guides and a small group of
   Spanish soldiers, traveled to the South Rim of the Grand Canyon between
   Desert View and Moran Point. Pablo de Melgrossa, Juan Galeras and a
   third soldier descended some one third of the way into the Canyon until
   they were forced to return because of lack of water. It is speculated
   that their Hopi guides must have been reluctant to lead them to the
   river, since they must have known routes to the canyon floor.
   Afterwards, no Europeans visited the canyon for over two hundred years.
     * Fathers Francisco Atanasio Domínguez and Silvestre Vélez de
       Escalante were two Spanish Priests who, with a group of Spanish
       soldiers, explored southern Utah and traveled along the North Rim
       of the Canyon in Glen and Marble Canyons in search of a route from
       Santa Fe to California in 1776.

American Exploration

   James Ohio Pattie, along with a group of American trappers and mountain
   men, was probably the next European to reach the Canyon in 1826,
   although there is little documentation to support this .

   Jacob Hamblin (a Mormon missionary) was sent by Brigham Young in the
   1850's to locate easy river crossing sites in the Canyon. Building good
   relations with local Native Americans and white settlers, he discovered
   Lee's Ferry in 1858 and Pierce Ferry (later operated by, and named for,
   Harrison Pierce) - the only two sites suitable for ferry operation.

   In 1857, the U.S. War Department asked Lieutenant Joseph Ives to lead
   an expedition to assess the feasibility of an up-river navigation from
   the Gulf of California. Also in a stern wheeler steamboat "Explorer",
   after two months and 350 miles (560 km) of difficult navigation, his
   party reached Black Canyon some two months after George Johnson. The
   "Explorer" struck a rock and was abandoned. Ives led his party east
   into the Canyon — they were the first Europeans to travel the Diamond
   Creek drainage and traveled eastwards along the South Rim.
     * The John Wesley Powell River Expeditions
     * The Brown-Stanton River Expedition
     * Other expeditions

Settlement on the rim

     * Miners
          + "Captain" John Hance
          + William W. Bass
          + Louis Boucher "The Hermit"
          + Seth Tanner
          + Charles Spencer
          + D. W. "James" Mooney
     * Lees Ferry
          + John Doyle Lee
          + Emma Lee (17th of John Lee's 19 wives)
          + J. S. Emmett
          + Charles Spencer
     * Phantom Ranch
          + David Rust
          + Mary Colter
     * Grand Canyon Village
          + Ralph H. Cameron
     * Federal protection

   Many challenges face the federal government administrators who manage
   park resources. These include issues related to: the recent
   reintroduction into the wild of the highly endangered California
   Condor, air tour overflight noise levels, water rights disputes with
   various tribal reservations that border the park, and forest fire
   management. The Grand Canyon National Park superintendent is Mr. Joe
   Alston who was previously the superintendent of Glen Canyon National
   Recreation Area (Lake Powell. Glen Canyon lies to the North and East of
   Grand Canyon on the Arizona/Utah Border.

Recent history

   In 1956 the Grand Canyon was the site of America's worst commercial
   aviation disaster at the time.

   On the morning of June 30, 1956, a TWA Lockheed Super Constellation and
   a United Airlines Douglas DC-7 departed Los Angeles International
   Airport within three minutes of one another on eastbound
   transcontinental flights. Approximately 90 minutes later, the two
   propeller-driven airliners collided above the canyon while both were
   flying in unmonitored airspace.

   The wreckage of both planes fell into the eastern portion of the
   canyon, on Temple and Chuar buttes, near the confluence of the Colorado
   and Little Colorado rivers. The disaster killed all 128 passengers and
   crew members aboard both planes.

   This accident led to the institution of high-altitude flightways and
   positive control by en route ground controllers.

Activities

   Aside from casual sightseeing from the South Rim (averaging 7000
   feet/2134 m above sea level), whitewater rafting, hiking and running
   are especially popular. The floor of the valley is accessible by foot,
   muleback, or by boat or raft from upriver.

   Hiking down to the river and back up to the rim in one day is
   discouraged by park officials because of the distance, effort required,
   and danger of heat exhaustion from the much higher temperatures at the
   bottom. Rescues are required annually of unsuccessful
   rim-to-river-to-rim travellers. Nevertheless, hundreds of fit and
   experienced hikers complete the trip every year. Hikers and runners who
   know their limits and have experience in a desert environment should
   not hesitate to undertake this fantastic journey. Weather is a primary
   consideration in this trip, so accurate forecasts are imperative. While
   the park service posts weather information at gates and visitor
   centers, this is a rough approximation only, and should not be relied
   upon for trip planning. For accurate weather in the Canyon, hikers
   should consult the National Weather Service's NOAA weather radio or the
   official NWS website .

   The canyon is extremely popular with endurance athletes, who regularly
   run across it. A one-way trip (rim-to-rim) takes place in around five
   to seven hours, or a round-trip (the rim-to-rim-to-rim or
   "doublecross") in around 11-14 hours. Allyn Cureton of Williams,
   Arizona holds the record for a north to south crossing at 3:06, set in
   1981. He also holds the record for the doublecross (South Kaibab
   version) at just under eight hours. Four runners (all experienced
   ultramarathon runners) have finished a "canyon quad" (four crossings in
   succession). Jim Nelson of Salt Lake City, Utah broke the speed record
   on November 6, 1999, with a time of 22:48. Previous to this, Wally
   Shiel established the quad record on October 4, 1987 with a time of
   24:45. Other finishers are Dana Miller of Parowan, Utah (1993) and
   David Crockett of Saratoga Springs, Utah (2006). Crockett added side
   trips on rim trails and the Tonto Trail during his 39-hour journey to
   make his the first 100-mile uninterrupted continuous foot trip in the
   Canyon. In March 2006 Phil Lowry of Springville, UT finished a 56-mile
   noncorridor route in 18 hours, travelling from Grandview Point to
   Phantom Ranch via the Tonto Trail, then out and back to Clear Creek and
   back to the rim via the Bright Angel Trail.

   The National Park Service provides wheelchairs for temporary day use by
   park visitors. No rental fee is charged.

   Grand Canyon South Rim

   Grand Canyon South Rim at Sunrise

   The Grand Canyon from inside

   The Grand Canyon as seen from Earth orbit.

   Two hikers looking down on the Grand Canyon

   Grand Canyon from Moran Point

   Grand Canyon backcountry

   Grand Canyon backcountry

   Grand Canyon backcountry

   Grand Canyon from Tiyo Point

   Sunrise at the Grand Canyon

   The Grand Canyon

   Sunset seen from South rim

   The United States government made the Grand Canyon a national park in
   1919

   Grand Canyon South Rim at Sunset

   View from Lipan Point at dawn

   View from the South Rim on the Kaibab Trail

   View from the North Rim at sunset

Grand Canyon Visitors

   Grand Canyon National Park is one of the world’s premier natural
   attractions, attracting about five million visitors per year arriving
   from all 50 U.S. states and Puerto Rico and internationally. Overall,
   83% were from the United States: California (12.2%), Arizona (8.9%),
   Texas (4.8%), Florida (3.4%) and New York (3.2%) represented the top
   domestic visitors. Seventeen percent of visitors were of foreign
   origins; the most prominently represented nations were the United
   Kingdom (3.8%), Canada (3.5%), Japan (2.1%), Germany (1.9%) and The
   Netherlands (1.2%).

Grand Canyon Fatalities

   About 600 deaths have occurred in the Grand Canyon since the 1870s.
   Some of these deaths occurred as the result of overly zealous
   photographic endeavors, some were the result of airplane collisions
   within the canyon, and some visitors drowned in the Colorado River.
   Many hikers overestimate their fitness level, become dehydrated and
   confused, and must be rescued. The Park Service now posts a picture of
   an attractive and fit young man at several trailheads with the caption
   "Many of them look like him", in an attempt to discourage hikers from
   feats which are beyond their abilities.

   According to Over the Edge: Death in the Grand Canyon, 50 fatalities
   have resulted from falls; 65 deaths were attributable to environmental
   causes, including heat stroke, cardiac arrest, dehydration, and
   hypothermia; 7 were caught in flash floods; 79 were drowned in the
   Colorado River; 242 perished in airplane and helicopter crashes (128 of
   them in the aforementioned 1956 disaster); 25 died in freak errors and
   accidents, including lightning strikes and rock falls; 47 committed
   suicide; and 23 were the victims of homicides.

   Retrieved from " http://en.wikipedia.org/wiki/Grand_Canyon"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
