GEOLOGICAL SURVEY OF THE TERRITORIES. 195 



climate, useful crops can be produced even here ; and prolonged exper- 

 iments have shown that even spots so thickly frosted over with alka- 

 line deposits as to destroy vegetable and animal life can be rendered 

 fertile and made to produce abundant crops. 



As a final illustration, I would refer to the efforts of the Mormons on 

 the Rio Virgin, along the Arizonian border, where I might truly say, 

 amid basaltic hills and drifting sands the desert is being turned into a 

 blooming garden. Perhaps a more desolate-looking region than the 

 vicinity of St. George could scarcely have been selected ; yet the ap- 

 plication of water shows that here, as elsewhere, the soil is rich in the 

 mineral elements necessary to fertility. 



Another fact with which our investigations must begin is, that as a 

 rule, which has but few exceptions, irrigation is necessary to the culti- 

 vation of the soil. 



As water is, therefore, the great desideratum in the agricultural 

 development of this country, in the method of its distribution we shall 

 find the true key to the agricultural systems of the West, and its turn- 

 ing sheds the boundaries of the districts. I adopted this as the basis 

 of the plan of rny report of last season, and subsequent and more ex- 

 tended observations and investigations have served to confirm me in 

 the position then taken. 



If I am correct in the foregoing opinions, then a general description 

 of the arable lands of this section implies a description of the portions 

 that can be irrigated. But a description of what may hereafter possi- 

 bly become arable widens the field and introduces the question of an 

 increase of moisture, with which I do not propose dealing at present, 

 but may allude to hereafter. 



Although there is not one monotonous uniformity throughout this 

 vast extent of country, yet there is nothing like the variety to be found 

 between the Mississippi and Atlantic. To know that a given spot is 

 covered with a sufficient depth of soil, and is susceptible of irrigation, 

 is to know that it will produce the cereals, the common vegetables and 

 fruits, except so far as limited by climate. The change in soil and veg- 

 etation in passing from the eastern to the western slope of the great 

 divide between the waters of the Atlantic and Pacific is far less than is 

 generally supposed. 



During the two years I have been connected with the United States 

 geological survey of these Territories, having traversed the country 

 north and south, from the banks of the Rio Grande to the southern 

 tributaries of the Yellowstone; and east and west from the plains east 

 of the Rocky Mountains to the Great Salt Lake basin, I shall give, in 

 as full and comprehensive manner as possible, in a short preliminary re- 

 port, a description of the various arable districts embraced within the 

 boundary mentioned, omitting what has already been reported upon. 

 Following out the plan already suggested, the different water-sheds, 

 and systems of valleys which lead to the large streams that drain the 

 country, will form the districts to be considered separately. And these 

 are generally so well marked that but little difficulty is experienced 

 in tracing them. 



The ceutral axis of the Rocky Mountain chain divides this area into 

 two unequal and irregular divisions ; the eastern division being drained 

 by the following rivers: the Rio Grande, the Arkansas, the Platte, 

 and the Big Horn, which form the water systems of the eastern shed 

 within the territory under consideration. The western division com- 

 prises two very different systems, the one being drained by Green River, 

 whose waters ultimately reach the Pacific through the Gulf of Oalifor- 



