410 



IRRIGATION. 



It must not l)e .supposed tluit there is no water to ))e had. On the 

 contraiT, occasional storms occur, sending down vast ([uantities of 

 water and inundating- the thirsty plain. This rushes ott' and in a few 

 hours the channels of the rivers are nearly dr3^ There are also, at 



Fi(j. 3.— Map showing location of forests and woodlands of the west. [The solid black indicates the 

 areas where trees valuable for lumber are growing, or recently have stood; the dotted areas show 

 the open woodlands with scattered trees valuable for fence posts or other farm purposes.] 



long- intervals, large perennial streams, but most of these tiow in 

 narrow, deep canyons. 



The country under discussion is not wholly uninhabited, but at 

 nearly every spring and along every river which is not flowing in a 

 narrow canyon there are to l)e found ranches and occasional small 

 towns. All of the easih' available sources of water supph' have been 



