110 Adventures in Scenery 



1853 by Professor William P. Blake, and was by him named the 

 Colorado Desert. There was then no State of Colorado, and 

 since this great geologic feature was built by a river bearing the 

 name of Colorado it was fittingly so named. This great river 

 deposit of sand and silt occupies the basin from the head of the 

 Gulf of California north to San Gorgonio Pass, a distance of 

 200 miles. It is a vast wedge-shaped or triangular area having 

 its base south of the International Boundary in Mexico and its 

 apex in San Gorgonio Pass between the San Jacinto and San 

 Bernardino ranges. On the northeast side are the Chocolate, 

 Chuckawalla, and San Bernardino ranges, and on the northwest 

 side the San Jacinto, Santa Rosa, and Superstition Mountains, 

 and in Mexico Signal Mountain and the Cocopah Range. Its 

 width at the International Boundary is about 80 miles. The 

 distance from the real mouth of the Colorado River, where it 

 debouches from the high plateau at Yuma, to the head of the 

 Gulf of California is about 60 miles in an air-line. This great 

 arid plain, built up of silt and sand carried by the Colorado 

 River to the Gulf of California embraces an area of more than 

 2,000 square miles. It is in large part below sea level. 



The Gulf of California once extended north to San Gor- 

 gonio Pass. The mouth of the Colorado River was near Yuma. 

 Here the river discharged its silt-laden waters into the gulf. 

 The Colorado now deviously meanders by ever-changing chan- 

 nels over the delta plain of its own building. Earth that has 

 been eroded from the mile-deep Grand Canyon of the Colorado 

 now rests in this plain in the basin of the Gulf of California. 

 It is estimated that the silt borne by the Colorado to its mouth 

 at the beginning of the delta plain is sufficient to cover one 

 square mile to a depth of 53 feet annually. 



The Building of the Delta 



When the river first discharged into the gulf at Yuma a 

 delta bar was built out into the water of the gulf, and continued 

 to be built higher and longer till a ridge extended toward the 



