Its horizontal strata retrace the geological history of the past 2 billion years. There are also prehistoric traces of human adaptation to a particularly harsh environment.
- United Nations (New York) 1984. Grand Canyon National Park.
Grand Canyon National Park
(1979)
United States of America
| Carved out by the Colorado river, the Grand Canyon (nearly 1,500 m deep) is
the most spectacular gorge in the world. Located in the state of Arizona, it
cuts across the Grand Canyon National Park.
Its horizontal strata retrace the geological history of the past 2 billion years. There are also prehistoric traces of human adaptation to a particularly harsh environment.
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Grand Canyon National Park was established in 1919, but originally a forest reserve established
already in 1893. Located in northern Arizona, the park contains the world-famous Grand Canyon of the Colorado River and includes the river’s entire course from the southern end of Glen Canyon National Recreation Area to the eastern boundary of Lake Mead National Recreation Area.
The great chasm has a maximum width of 29 km (18 mi) within the park, and it is about 1,500 m (5,000 ft) deep. The northern rim of the canyon is on the average 365 m (1,200 ft) higher than the southern rim and is closed to sightseers from October to May because of heavy winter snows. Paved roads wind around the rims of the Grand Canyon, and trails descend into the canyon, although only one of them, the Kaibab Trail, crosses the gorge from rim to rim.
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The extreme variations in elevation from the depths of the canyon to the northern rim create four distinct zones of climate and plant life. Dense virgin forests of aspen, pine, fir, and spruce grow on the colder northern rim, and the southern rim is sparsely covered with piñon and juniper. Wildlife includes deer, antelope, cougar, and mountain sheep. Prehistoric Native American groups lived in the canyon and on its rims; ruins of pueblos and cliff dwellings remain. The park is bordered on the south by the reservation of the Havasupai people.
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In 1975 the park was nearly doubled in size by the inclusion of Grand Canyon National Monument (proclaimed in 1932) and Marble Canyon National Monument (proclaimed in 1969) and portions of Glen Canyon and Lake Mead national recreation areas.
The effects of tourism and federal water management policies led the government to take steps to protect the canyon’s environment during the 1990s.
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In March 1996 a controlled flood through Glen Canyon Dam was generated as a way to re-create natural spring flooding through the canyon. The results of this led to a new water-management plan. This plan incorporates flooding to restore the canyon’s natural ecosystems, which had been changed by the construction of Glen Canyon Dam in 1963. In 1997 the government restricted small planes and helicopters from flying over the canyon and was considering other ways to limit the effects of tourism on the park.
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Sources and links:
Other World Heritage Sites in USA (on this site). Inactive links are not described on stamps. Please refer to the UNESCO-listing, section United States for further information about such sites.
Revised 03 aug 2006 |
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