Grand Canyon National Park
Grand Canyon National Park comprises 1,218,375 acres (493,058.9 hectare) and lies on the Colorado Plateau in the northwestern part of the U. S. State of Arizona. The land is semi-arid and consists of raised plateaus and structural basins.
The Canyon, cut by the Colorado River, averages 4,000 feet (1,219 meters) deep and is 277 miles (446 kilometers) long. It is 6,000 feet (1,829 meters) deep at its deepest point and 15 miles (24 kilometers) at its widest.
The park has five of the seven life zones and three of the four desert types in North America.
On-going erosion by the seasonal and permanent rivers produces impressive waterfalls and rapids of washed-down boulders along the length of the canyon and its tributaries.
There are over 100 named rapids. Exposed horizontal geological strata in the canyon provide evidence of the four major geological eras; late Precambrian, Palaeozoic, Mesozoic, and Cenozoic.
First protected in 1893 as a forest reserve in which mining, lumbering and hunting were permitted; upgraded to a game reserve in 1906, giving protection to the wildlife; redesignated a national monument in 1908; and declared a national park in 1919.
It was included on the World Heritage List in 1979.
Many buildings and structures constructed during the 1930s have been placed on the National Register of Historic Places.
The park contains more than 2,600 documented prehistoric ruins, including evidence of Palaeo Judiou and Archaic cultures, Cohonina Indians along the South Rim, and Anasazi Indians on the South Rim and the North Rim, and within the Inner Canyon.
Sometime after 1200 CE, the canyon was abandoned, with reoccupation occurring after 1300 CE. Hualapai and Havasupai Indians moved into the canyons at this time, where they remained undisturbed until the Anglo-Americans arrived in 1860.
See map of the park.
(This page was updated in November 2012.)