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Conservation Reader 



Brown Brothers 

 The great Roosevelt Dam, in the Salt River irrigation project, Arizona. 



of the Mississippi River upon the Gulf of Mexico. Another 

 is upon the Northwest coast. Throughout the central part 

 of the country the summer rains are sometimes too light to 

 afford a full harvest. The rainfall upon the plains and 

 valleys of the Southwest is so small that the only plants 

 that can live there are those strange and curious forms that 

 have become used to desert conditions. The only way in 

 which these lands can be made useful to the farmer is by 

 means of irrigation. To obtain water for irrigation we 

 have either to go to the distant mountains and build reser- 

 voirs to collect the rains which fall there and then dig canals 

 to carry the water to the desert valleys, or to make use of 

 some river flowing through them, if they are fortunate 

 enough to have such a river. Can you think of any rivers 

 that are used in this way? 



