74 LANDS OF THE ARID REGION OF THE UNITED STATES. 
1. By plowing the earth the farmer has rendered it more porous and 
absorbent, so that a smaller percentage of the passing shower runs off. He 
has destroyed the native vegetation, and replaced it by another that may 
or may not increase the local evaporation; but this is of little moment, 
because his operations have been conducted on gentle slopes which in their 
natural condition contributed very little to the streams. It is of greater 
import that he has diverted water already accumulated in streams, and for 
the purposes of irrigation has spread it broadly upon the land, whence it is 
absorbed by the air. In this way he has diminished the inflow of the lake. 
Incidental to the work of irrigation has been what is known as the 
“opening out” of springs. Small springs are apt to produce bogs from 
which much water is evaporated, and it has been found that by running 
ditches through them the water-can be gathered into streams instead. The 
streams of water thus rescued from local dissipation are consumed in irriga- 
tion during a few months of the year, but for the remainder go to swell 
the rivers, and the general tendency of the work is to increase the inflow 
of the lake. A similar and probably greater result has been achieved by 
the cutting of beaver dams. In its natural condition every stream not sub- 
ject to violent floods was ponded from end to end by the beaver. Its water 
surface was greatly expanded, and its flood plains were converted into 
marshes. The irrigator has destroyed the dams and drained the marshes. 
There are a few localities where drainage has been resorted to for the 
reclamation of wet hay lands, and that work has the same influence on the 
discharge to the lake. 
2. The area affected by grazing is far greater than that affected by 
farming. Cattle, horses, and sheep have ranged through all the valleys 
and upon all the mountains. Over large areas they have destroyed the 
native grasses, and they have everywhere reduced them. Where once the 
water from rain was entangled in a mesh of vegetation and restrained from 
gathering into rills, there is now only an open growth of bushes that offer 
no obstruction. Where once the snows of autumn were spread on a non- 
conducting mat of hay, and wasted by evaporation until the sunshine 
came to melt them, they now fall upon naked earth and are melted at once 
by its warmth. 
