National Geographic : 1909 Aug
VoL. XX, No. 8 WASHINGTON AUGUST, 1909 [ThE M~ LI - MAG A ElNB THE COLORADO DESERT* BY W. C. MENDENHALL, OF THE U. S. GEOLOGICAL SURVEY With Photographs by the Author THE Colorado Desert is not in Colorado nor even near that im perial State. Instead, it is in the extreme southeastern part of California and adjoining parts of Mexico, and represents one of the geographical and physical extremes for which California is noted. This state extends for 1,000 miles north and south along our Pacific shore line, so that it passes from tropical to temperate conditions and from the most arid to one of the most humid sections of the continent. It includes the great Sierra, dominated by Mount Whitney, 14,501 feet above the sea, while just east of this culminating peak of the United States lies Death Valley, the lowest point on the continent, 276 feet below sea-level. These physical contrasts are matched by contrasts in vegetation and temperature, so that nearly every type of natural environment under which man exists is represented within the boundaries of the state, and often, as in the case of Death Valley and Mount Whitney, the juxtapo sition is so immediate as to greatly ac centuate the contrasts. The valley of southern California, with its orange and lemon groves, its acacias and palms, its geranium hedges, and its riot of roses, is only 1oo miles from the region that is the subject of this sketch, originally one of the most deso late spots on the globe, a veritable fur nace in midsummer, with recorded offi cial temperatures of 130 degrees in a shadeless land, but now destined through the agency of man to become a unique agricultural section, in which products not capable of product:on elsewhere in the United States can be successfully grown. This desert derives its name from the Colorado River, its creator and until re cently the erratic master of its destinies. Now the river is sullenly yielding to man the dominion that it has maintained since the evolution of the desert from sea bot tom to arid valley. This evolution is a very recent event, in a geologic sense, and is one which the scientist is able to decipher with exceptional and satisfac tory definiteness. The desert valley is a northeastward extension of the depression whose south ern portion is filled by the Gulf of Cali fornia. During a time that is not at all remote, geologically speaking, the gulf occupied all of this depression, extending * Published by permission of the Director, U. S . Geological Survey.