The Colorado River has been at work on the Grand Canyon for about 17 million years, and has eroded a chasm 277 miles long, 18 miles wide and more than a mile deep. This part of northern Arizona was settled in about the 13th century BC by the Ancestral Puebloans, a Native American culture referred to by the present-day Navajo people as Anasazi or “Ancient Ones”. Several additional ancient native cultures migrated into the area between about 500 and 1500 AD. Several aboriginal nations were found when Europeans first arrived in the 15th century AD, chiefly the Navajo and also the Hopi, Havasupai, Halupai and Paiute.
The Grand Canyon