As we look into the distance at the Vermillion Cliffs we are looking at the source of Seven Mile Wash. The wash begins just at the base of the Vermillion Cliffs which are only a straight line distance away of less than two miles. By the time the wash crosses under highway US 89 it is still only 20 feet below the surrounding plains, and it is now only a mile and a quarter away from the river. It is not until it is only a half mile away that it begins to deepen in earnest. That is where the wash plunges from being about 100 feet deep to over 300 feet deep. When the wash finally intersects the north wall of the Grand Canyon it has become 500 feet deep.
GCPano.org