332 ECONOMICS OF FORESTRY. 



about 700 million acres, 1 of which less than 40 per 

 cent, or less than 300 million acres, have been 

 turned into farm lands, and an unknown acreage 

 has been culled of its valuable stores of timber, 

 ravaged by fire, or turned into useless brush lands. 



The area to the west, almost twice as large, 

 1 200 million acres, is mainly a forestless, often 

 treeless area into which stretch like narrow penin- 

 sulas of varying width from the north the forested 

 mountain ranges of the Rockies, not exceeding 

 100 million acres of woodlands and the forest of 

 the Sierras and coast ranges of the Pacific with 

 nearly the same acreage. 



The Atlantic forest occupying the humid regions 

 of the United States and covering both valleys and 

 mountains, composed of a large variety of broad- 

 leaved species with conifers intermixed, gradually 

 changes to the westward into the prairie country, 

 practically forestless, although not treeless, where 

 trees and forests of an inferior character are capa- 

 ble of growing, but where the grasses are able to 

 compete successfully with the arborescent flora. 



To the west of the prairie belt lie the plains 

 and semi-arid regions, including deserts, irrigable 



1 The figures used in this chapter lay no claim to statistical ac- 

 curacy but are merely rough approximations, sufficient to give a 

 general idea of relationships, such as the economist needs. There 

 are no accurate data at hand ; when not even the areas of the different 

 states are accurately known, official authorities differing widely, it 

 is useless to attempt anything but rounded-off figures. 



