The Irrigation Problem in Montana. 223 
to force the young sprouts above the surface, rather than run the 
risk of its crusting and thus preventing them from breaking 
through. 
These bottom lands though really the poorest for irrigating, 
are nearly the only lands now cultivated, because of the greater 
ease and cheapness of supplying them with water. From two to. 
three tons of hay and from 35 to 50 bushels of grain per acre are 
raised even on these inferior soils. 
The best, and by far the more abundant agricultural lands, are 
the “bench lands,” these are situated high above the stream beds 
and the soil is usually a warm open, rich, sandy-loam, several 
feet in depth and usually underlain by a deep bed of gravel. 
Though in irrigating, this soil at first requires more water, it 
will, owing to its excellent natural drainage, last for all time and 
will neither clog with water nor cake on the surface. 
It is these bench lands which will be rendered irrigable by 
vovernment aid and surveys, though to develop them will require 
large amounts of capital ; still, they are so extensive in area that 
the work can generally be conducted on a grand and economical 
scale. 
Duty or WATER. 
From the meagre information now obtainable it is probable 
that in average soils and for the staple hay, grain and vegetable 
crops in Montana, about one cubic foot of water per second, flow- 
ing during the irrigating season, will be sufticient for 100 acres ; 
this quantity is known as the “ duty of water.” 
The irrigating season lasts about three months. While the 
crops are maturing during part of May, June and July, they will 
receive two or three waterings, and in early September the hay 
lands are again watered in order to start the growth of grass 
before the frosts. 
In case all the surplus water of a given stream is stored, the 
duty of that stream will be increased by the amount of water 
now flowing to waste during the remaining nine months, and as a 
portion of this time is the flood period, owing to the melting of 
the snows in the mountains and to the spring rains, this storage 
water will increase the duty of the stream at least five-fold ; that 
is, five times as many acres may be irrigated by the stream as at 
present, provided that storage capacity can be found for all of its 
waste waters. 
