22 Miscellaneous Circular 48, U. S. Dept. of Agriculture 



Clark Fork watershed has sites which would produce a total of over 

 620,000 horsepower. A power plant at Thompson Falls now de- 

 livers 60,000 horsepower. One of the largest sites, with a possi- 

 bility of 205,000 horsepower, is on the Flathead River, below Poison. 

 The Kootenai River has two potential power sites. A dam 480 

 feet high, which would develop about 100,000 horsepower, has been 

 considered at the Big Horn Canyon on the Big Horn River about 

 30 miles above Hardin. 



There are also power sites on the small rivers and creeks, which, 

 although they supply but a small amount of water, have a great fall 

 in a short distance. Many such sites are now developed for supply- 

 ing power to mines and stamp mills, and for lighting purposes in 

 small towns. 



Electricity now hauls the trains of the Chicago, Milwaukee & St. 

 Paul Railway across the Rockies and the Bitterroot Mountains. The 

 Butte, Anaconda & Pacific Railroad, over which passes practically 

 all the ore used at the great Anaconda smelter, has been operated by 

 electricity for years. Electric power is used in the great mines 

 around Butte, and has supplanted steam power in numerous other 

 industries. 



To provide a constant supply of water is one of the big problems 

 of the water-power and irrigation engineer, and the solution de- 

 pends to a large extent on the protection afforded by the forests at 

 the heads of streams. A covering of trees keeps the winter snow 

 from melting too quickly and prevents rapid evaporation of sum- 

 mer rains. The forest floor, with its duff and litter, acts as a 

 sponge to hold water which seeps into it instead of running off the 

 surface. Denuded areas, with little shade to protect the snows and 

 with shallow soil lacking in vegetable duff to hold the moisture, 

 are poor assurance for power developments involving the invest- 

 ment of millions of dollars. 



Including within their boundaries great areas of mountainous 

 country where streams have their sources, the national forests of 

 the State are of great value to the water-power industry. In fact, 

 the value of many of these forests lies chiefly in their use for water- 

 shed protection. Extensive areas of lodgepole-pine timber on such 

 forests as the Absaroka, Beaverhead, and Madison are of special 

 importance from this standpoint and are treated accordingly, so 

 that the stability of industry dependent upon the rivers which they 

 feed is assured. 



It must not be supposed, however, that the timber on such a 

 forest must be left unused in order to maintain the value of the 

 forest as a protective cover. By the application of practical for. 

 estry methods the great lodgepole forests can be made to yield many 

 products, such as mine timbers, fence posts, and poles and ties, with- 

 out the least reduction in their value as regulators of run-off. Pro- 

 tection from forest fire, that greatest of all denuding agents, must 

 be assured, and is one of the chief safeguards the Forest Service 

 aims to provide. 



IRRIGATION 



Irrigation antedates the discovery of gold in Montana. Father 

 DeSmet, a Jesuit priest, introduced the art in the Bitterroot Valley 

 in 1845, and a small irrigated settlement grew up around St. Mary's 



