THY WATERS, GATHERED FROM THE SNOWS AND SPRINGS
AMID THE UTAH HILLS, HAVE CARVED THIS ROAD
OF GLORY TO THE CALIFORNIA GULF.”
—HENRY VAN DYKE
Very difficult is it for the average human fully to realize, to comprehend the tremendous power of running water. One does not question the origin of a wayside gulch cut out by recent storms, nor is it hard to visualize the formation of some steep-walled glen where a fast-rushing stream is found at work in its bottom. The vast Grand Canyon, however, an extreme example of erosion, seems a bit too large—too wide and deep—to be attributed alone to the power of any river such as exists today. But the Grand Canyon—the greatest of chasms—is nothing more than the result of the work of running water over a long period of history.
CROSS SECTIONS OF GRAND CANYON
NEAR THE WESTERN END OF NATIONAL PARK. ROCKS OF THE THIRD ERA ALONE HERE FORM THE CANYON WALLS. THOSE OF THE FIRST ERA ARE PROBABLY NOT FAR BELOW THE RIVER BED.
CENTRAL OR BRIGHT ANGEL AREA. THE INNER GORGE IS CUT IN HARD VERTICAL ROCKS OF THE FIRST ERA (ARCHEAN). THE UPPER CANYON WALLS ARE FORMED OF HORIZONTAL ROCKS OF THE THIRD ERA. THE TILTED STRATA OF THE SECOND ERA WERE HERE WORN AWAY EXCEPT TO THE LEFT OF THE GORGE.