National Geographic : 1900 Sep
THE TIIE NATIONAL GEOGRAPHIC MAGAZINE VOL. XI SEPTEMBER, 1900 No. 9 THE COLORADO DESERT By DAVID P. BARROWS The Colorado River, its canon valley, and flood-plain constitute a series of physiographic conformations of impressive variety. The upper part of its course has been eroded across the great elevated plain of western America, through which it has cut its channel down ward with so great rapidity that its valley walls, almost unaffected in comparison by weathering, rise sheer upward in the gigantic system of gorges known as the Grand Canon of the Colorado. From the point where it enters California it is no longer a downward eroding stream, but sweeps grandly across the sterile plain of the desert, a dark, sediment-laden current, swinging back and forth across its widening valley. As it nears the Gulf of California and the rapidity of its stream lessens, the enormous loads of fine rock material, cut from the valleys through which it has torn its way, are deposited in a great flood plain or delta, across which the stream pours south into the gulf. As above this delta the low banks are unwatered, except at the very margins of the river, the sterility of the surrounding country is un affected by its immense volume of water. From whatever direction you approach the river within California or Arizona, the trail lies across sandy hill and thirsty plain, where are the dark marks of old volcanic activity, grotesque rock forms, shaped by wind erosion, and occasional stunted clumps of desert plants, with extremely modified foliage; but nowhere is there suggestion that you are upon the banks of the mightiest river of western America, until suddenly the ground drops slightly, and in an instant there come the dark green coloring of mesquite growth, the bright foliage of cottonwood and willow, the dazzling gleam of wide waters, flowing swiftly, and you are beside the long, shining river of Lopez de Cardenas and Alarcon.