CHAPTER IV. 



GENERAL FOREST ASPECTS. 



THE forests of Montana cover about one-third the area of 

 the State, or nearly 50,000 square miles. Over much of 

 this area the landscape is diversified by alternate forest 

 and prairie, and the forests, thus divided, extend further east 

 and west and reach to farther limits than the statement in square 

 miles would imply. The forests are continuous for considerable 

 distances only, -as a rule, above certain altitudes (4000-5000 

 feet) ; below this forests and prairies alternate. The western end 

 of the state, owing mainly to climatic conditions, is far more 

 heavily timbered than the part east of the Continental Divide. 

 From the western boundary eastward the forests in the southern 

 part of the state become gradually more open ; in the northern 

 part their volume is better sustained. The rainfall is much 

 heavier in the northwestern part than in the southwestern and 

 the forest development proportionately greater. It presents on 

 the whole a more rugged topography and a greater variety of 

 exposure and shelter. The heavier precipitation is reflected in 

 the drainage and the frequent lakes, springs and streams pro- 

 vide the mesophytic conditions requisite for heavier forests and 

 a greater variety of species. Prairies are smaller and less nu- 

 merous and continuous forests occur at lower levels, at 4000 feet 

 and above. 



In the southwestern part of Montana the lower margin of 

 the continuous forest is at least 1000 feet higher than in the 

 north. About the head of the Bitter Root, the Jefferson and 

 the Big Hole the grasslands may extend in some places to 6000 

 feet or even more. The topography is less rugged, the country 

 much drier, and the forests accordingly more open. The forest 

 here is sufficiently open to admit grasses and other herbaceous 

 plants. The number of shrubs, however, is much less than in 

 the north, both as to species and individuals. 



Throughout the region coniferous vegetation is dominant. 

 Yellow pine and Douglas spruce are the prevailing species over 

 the greater part of the region, as seen from the highways. Broad 



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