The whole delta is deposited in regular strata from 0.01 inch to 2 

 or 3 inches in thickness, most of the soils presenting the appearance 

 in cross section of a shale or argillaceous sandstone. These strata 

 are for the most part horizontal good cross sections being exposed in 

 the cuts of New and Salton rivers. Along Superstition Mountain, 

 about 15 miles west of Imperial, the sediments have been uplifted and 

 broken, exposing the deposits to a great depth. An examination of 

 this section shows that the same general character of deposits extends 

 to a depth of 500 feet. Several species of shells are found on the sur- 

 face of the desert. Mr. Simpson, of the Smithsonian Institution, has 

 identified these shells as fresh or possibly brackish water species 

 which are found living to-day under suitable conditions. These would 

 indicate that the surface of the desert was formed from fresh water or 

 water slightly brackish. The presence of other beach lines below the 

 line of present sea level is supposed to show that there have been 

 periods of partial refilling of the basin from the extreme floods of the 

 Colorado River. Such a refilling on a small scale occurred in lsil, 

 when the bottom of the basin at Salton was flooded. During these 

 times of partial refilling with fresh water these fresh-water shells were 

 either washed in with the sediments or lived along the niud flats 

 covered with shallow water. 



DEVELOPMENT OF THE IRRIGATION SYSTEM. 



Ever since the Colorado Desert was surve\ 7 ed in 1854, schemes have 

 been discussed to bring the water of the Colorado River to the land. 

 Actual work on surveys for the canal s\'stem began in 1801, when 

 Mr. C. R. Rockwood became identified with a company whose first 

 plans were to take the water out a few miles above Yuma. carry it 

 down, and flume across the river the water to be used on lands in 

 Mexico. In the financial panic of 1803 this company went to pieces. 

 The difficult engineering features of this project prevented it from 

 again being seriously discussed. With great tenacity of purpose, 

 Mr. Rockwood continued to devote his time and energies to inter- 

 esting capital in irrigating at least a part of the desert, and the result 

 was the formation in 1000 of the California Development Company. 

 This company is made up of a corporation in both the United States 

 and Mexico, since a part of the company's works and canals are in 

 Mexico. 



The California Development Company is a stock company, the 

 shares of which may be disposed of at will by the owners. It is not 

 the policy of the company to actually irrigate lands in the United 

 States, but to sell water to mutual irrigation companies at the herder 

 line, these companies having contracts which specify that not more 

 than 50 cents per acre-foot will ever be charged for Avater and that at 

 least 1 acre-foot of water must be paid for each y ear on every acre of 



