11 



is .safe to assert that at the present time tliere are over 1,500,000 aeres 

 under irrig-ation. This hirge area, comprisino- 70 per cent of the farm 

 homes and much of the choice hinds of the State, yields an average 

 return of about $25,(»00,0O0, Much of this is paid to the merchant for 

 food and wearing apparel, to the manufacturer for farm implements, 

 to the transportation companies in payment of freight charges, or to 

 county and State in paA^ment of taxes. It is thus apparent that this 

 basic industry of irrigated agriculture is not only serving to develop 

 the resources of a new State, but at the same time it is promoting the 

 welfare of other important industries. 



THE WATER SUPPLY. 



For an arid State, ^Montana is well watered. Occupying as it does 

 the crest of the continent, many rivers have their source and flow 

 from its elevated ranges and mesas. Some of these streams have not 

 as yet been utilized to any great extent for irrigation, and in conse- 

 quence their wat(u- has little present value. Others are partially util- 

 ized, while still others have been wholly appropriated. However, 

 onlv a few of the larger streams have ever been measured and little is 

 known of the discharge of scores of the smaller rivers and creeks. 

 The following summarv of the annual discharge of some of the prin- 

 cipal rivers in 1903, as determined hy the engineers of the United 

 States Geological Survey, may convey some idea of the extent of the 

 water supply: 



Discharge of Montiuui rirers, I'.tOS. 



Acre-feet. 



Yellowstone River at Livingston 2, 654, 000 



Gallatin River at Logan 841, 000 



Madison River at ]Morris 1, 265, 000 



Jefferson River at Sappington 1, 872, 000 



Bitter Root River at Grantsdale 1, 128, 000 



Missoula River at Missoula 2, 459, 000 



Big Blackfoot River at Bonner 1, 026, 000 



Marias River at Shelby 1, 183, 000 



St. Mary River at International Line 1, 213, 000 



Total « 13, 641, 000 



The water suppl}' for 1903 was about normal. On account, how- 

 ever, of the short irrigation season the full flow of streams can not 

 be utilized without storage for more than a third of the year. It is 

 true this growing period occurs at a time when the rivers are high, 

 but even with this favorable condition it is not possible to utilize for 

 irrigation purposes more than one-half of the total yearly flow. The 

 data regarding the quantities of water which can be retained in the 

 smaller streams are too limited and uncertain to enable one to estimate 



« The Missouri River is not included for the reason that the greater part of its dis- 

 charge is derived from the Gallatin, Madison, and Jefferson rivers. 



