THE COLORADO DESERT 



691 



Development from that time until 1904 

 was rapid, but the silt carried by the 

 Colorado River tended to clog the canals 

 of the irrigation system and to make it 

 difficult to secure sufficient water through 

 them to irrigate the tributary lands. In 

 order to overcome this difficulty, new in- 

 takes were repeatedly cut at the head of 

 the system, and during the flood period 

 of 1905 the river, enlarging one of these 

 intakes, abandoned its normal course to 

 the Gulf of California and, following the 

 Imperial Canal nearly to the interna- 

 tional boundary, flowed again into the 

 Salton depression as it had doubtless 

 done at many periods in prehistoric time. 



So we had the strange spectacle of a 

 mighty river wholly abandoning the 

 lower 80 miles of its course and ceasing 

 utterly to discharge into the sea. During 

 the next two years repeated efforts were 

 made to redivert the river from its course 

 inland to that toward the gulf ; but these 

 were all unsuccessful until February, 

 1907, when, after the expenditure of hun- 

 dreds of thousands of dollars, the stream 

 was finally controlled and the menace to 

 the valley removed; but during the two 

 years or more of inflow a great lake 

 nearly 500 square miles in area had ac- 

 cumulated in the bottom of the Salton 

 depression to a depth of nearly 80 feet, 

 inundating 40 or 50 miles of the main 

 transcontinental line of the Southern 

 Pacific and forcing that road to rebuild 

 on higher lines at great expense.* 



With the control of the river regained 

 and the menace to property interests in 

 the valley thus removed, development, 

 suspended for a long time, has been re- 

 sumed at a rate that promises to more 

 than make up for the delay. 



The principal elements in the history 

 of this extraordinary region may be 

 briefly summarized: First, in earlier pre- 

 historic time it was an arm of the Gulf 

 of California; then, perhaps during the 

 Middle Ages of human chronology it had 

 become an interior lake, separated from 

 the gulf by the delta of the Colorado 



* For further description of this break of the 

 Colorado River see "The New Inland Sea," by 

 A. P. Davis, in NaT. Geog. Mac, January, 1907. 



River; after its separation the lake 

 eventually evaporated and its site became 

 the hottest and dryest as well as one of 

 the lowest points in the United States. 

 It was in this condition when it first be- 

 came known to civilized man. 



By the practice of the art of irrigation 

 a part of it was later transformed from 

 an absolute desert to a unique agricul- 

 tural community, but as an incident in 

 this reclamation a lake has again been 

 created in the bottom of the depression, 

 and for a long and anxious period there 

 was serious clanger that the inundation 

 might extend over practically all of the 

 lands that had been reclaimed. Fortu- 

 nately this menace is passed and develop- • 

 ment again continues unimpeded by fear 

 that the erratic river will destroy what 

 in times past it has created. 



The desert is interesting for other rea- 

 sons than those due to its strange history. 

 Within it or about its borders are most 

 striking land forms of bizarre types. 

 East of Holtville is a zone of sand dunes 

 12 miles wide and 50 miles long — a re- 

 gion unsurpassed in aridity and in men- 

 ace to the inexperienced traveler by the 

 worst of the Saharan or Tibetan deserts. 

 (See page 700.) 



In the western edge of the Imperial 

 Valley, at the east base of the Peninsula 

 Range, are bad lands quite equal in pic- 

 turesqueness and in uselessness to the 

 worst of the Dakota bad lands. (See 

 page 696.) 



The rare torrential storms of the re- 

 gion have caused the streams that drain 

 from the bordering mountains into the 

 desert to cut strikingly deep, narrow 

 canyons through the sandstones around 

 the desert margin. Some of these cleft- 

 like gorges are scarcely wide enough at 

 the bottom for a man to pass, yet have 

 walls two hundred feet high or more. 

 Others are broader and deeper, but with 

 sheer sides that cannot be scaled except 

 where broken down at the junction of 

 some tributary arroyo. (See page 693.) 



Among the most incongruous elements 

 in the desert physiognomy are two 

 groups of mud volcanoes that seem 

 uncanny, so strangely out of place are 



