Admission to Grand Canyon National Park is valid for seven days and includes both the South Rim, and during its season, the North Rim . The park charges $35 for a private vehicle, and $20 per person for hikers, bicyclists and pedestrians.

Researchers say the ancestral Colorado River formed an ancient lake in northern Arizona roughly 6.6 million years ago, which spilled out westward onto the landscape that would eventually become the Gr