Grand Canyon

The Grand Canyon cuts across the Colorado Plateau in northern Arizona for more than three hundred kilometres. Its value lies not only in its scale but in what it exposes: the progressive incision of the Colorado River has sliced through an almost continuous succession of strata reaching from Precambrian metamorphic rocks, at the bottom of the gorge, to Permian limestones at the rim. It is one of the most complete and most accessible geological sections on the planet. The difference in altitude between the north rim and the canyon floor creates a staircase of environments running from conifer forest to desert scrub, with plant communities that horizontally would require travelling thousands of kilometres. Its wildlife includes the California condor, reintroduced to the region after coming close to extinction. The canyon is part of the ancestral territory of several Native nations, among them the Havasupai and the Hualapai, who maintain a presence there.