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Portrait of The Grand Canyon

Geography · Physical geography

The Grand Canyon

national park since 1919

Colorado River gorge in northern Arizona — 446 km long and over 1.8 km deep

A gorge cut by the Colorado River through the Colorado Plateau in northern Arizona, some 446 kilometres long, up to 29 kilometres wide and more than 1,800 metres deep at its deepest. Its walls expose close to two billion years of rock, from young limestones at the rim down to the Vishnu Schist at river level. Much of it lies in a national park created in 1919 and World Heritage listed in 1979.

How to spot them

  • ▸A mile-deep river gorge in Arizona with banded red and ochre walls, in a national park since 1919
  • ▸Quiz clue: 'Colorado River', 'John Wesley Powell', 'Vishnu Schist', 'South Rim', 'Havasupai'
  • ▸Not the deepest canyon in the world, despite the name — that record lies in Asia and South America
  • ▸Its rims are only about 16 km apart but roughly 350 km by road

Key facts

A one-armed Civil War veteran ran the Colorado through it by boat in 1869 and named many of its features (1869)

John Wesley Powell, later director of the US Geological Survey

Theodore Roosevelt made it a national monument in 1908; Congress made it a national park in 1919 (1919)

Roosevelt's 1903 visit produced the plea to leave it as it is

At its floor lies the Vishnu Schist, rock roughly 1.75 billion years old

The Inner Gorge; the rim rocks are a mere 270 million years old

A gap of well over a billion years in its rock record is known as the Great Unconformity

Young sediments rest directly on far older basement rock

The Havasupai people live in a side canyon famous for blue-green travertine waterfalls

Supai village and Havasu Falls, the most remote community in the lower 48 states

Mules still carry visitors down the Bright Angel Trail to a ranch beside the river

Phantom Ranch, at the bottom of the Inner Gorge

In 1956 a mid-air collision above it killed 128 people and led to the creation of the US Federal Aviation Administration (1956)

A TWA Super Constellation and a United DC-7

A glass horseshoe walkway juts out over its western reaches, on Hualapai tribal land outside the national park (2007)

The Skywalk at Grand Canyon West

Quick-fire facts

  • •About 446 km long, up to 29 km wide, and over 1,800 m (roughly a mile) deep
  • •Cut by the Colorado River through the Colorado Plateau in northern Arizona
  • •Grand Canyon National Park was established on 26 February 1919; World Heritage listed in 1979
  • •John Wesley Powell led the first documented run of the river through it in 1869
  • •The oldest exposed rock, the Vishnu Basement Rocks, is around 1.75 billion years old
  • •The South Rim is open all year; the higher North Rim closes in winter
  • •The Grand Canyon Skywalk, a glass horseshoe walkway, is on Hualapai tribal land outside the park
  • •It is not the world's deepest canyon — the Yarlung Tsangpo Grand Canyon and Peru's Colca and Cotahuasi canyons are deeper
  • •The Bright Angel and South Kaibab trails are the main routes to the river

Drill it — 9 cards

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Sources