The Grand Canyon has an average depth of 4,000 feet, according to the National Parks Service. At its lowest point, the canyon is 6,000 feet deep . At its widest, the canyon spans 18 miles across.

The Grand Canyon is the biggest canyon on earth: 277 miles long, 10 miles wide, and a mile deep. It contains some of the oldest exposed rock on earth, Precambrian Vishnu schist, formed 1.7 billion ...

“Leave it as it is,” declared U.S. President Teddy Roosevelt after a 1903 sojourn at the Grand Canyon. “You cannot improve on it. The ages have been at work on it, and man can only mar it ...