170 



THIRD ANNUAL SESSIONS 



Precipitation. 



"While the average amount for the state is 13.68 inches, there is a 

 wide variation in the normal amounts received over the various sections 

 of the state. There are portions of Big Horn and Sv^eetwater counties 

 where the average amiual precipitation is probably less than 5.00 inches, 

 while over the extreme northeastern and extreme northwestern portions 

 of the state there may be a few sections where the annual average is 

 nearly 20.00 inches. On a map which I have prepared to accompany this 

 paper, I have endeavored to show the geographical distribution of the 

 rainfall throughout Wyoming; the peculiar and complicated topography 

 of the state causing a wide variation in the annual precipitation over the 

 various sections. The unshaded portions of the map show areas of the 

 state where the average annual precipitation is less than 10.00 inches, 

 and you will notice that those areas embrace only portions of Big Horn 

 county and the red desert region, the aggregate of which is only a small 

 percentage of the total area of the state. I believe that most of the dry 

 farming experts of today do not advise that dry farming be attempted 

 in regions where the annual precipitation is less than 10.00 inches, so 



the unshaded portions of the map show regions where dry farming at- 

 tempts should not be made at the present day. The darkest shadings 

 represent areas where the average annual precipitation is in excess of 

 J 5.00 inches, and here again you will notice that those areas represent 

 only a small percentage of the total area of the state. It is probable 

 that about 75 per cent, of the total area of the state is embraced within 



