Timber of the Western States. The Rocky Mountains. 87 



ered with heavy timber, excepting in "oak openings" and "bar- 

 rens," where the trees had been destroyed by frequent fires, and the 

 " prairies," where from this or other causes no timber was found, 

 except along the borders of streams. 



312. These open spaces of every description, when drained and 

 protected, are found to produce trees readily under cultivation, there 

 being scarcely any part that presents an inherent difficulty in the 

 soil, and none in the climate. 



313. According to the writer above cited, the country north-west 

 of the Ohio river, contains from one hundred and five to one hun- 

 dred and ten native species, of which sixty-eight to seventy grew to 

 a height of fifty feet. In Southern Ohio and Indiana, oaks and 

 various hard-woods grow to a very large size, and the walnuts, bass- 

 wood, and tulip-tree attain their finest development. 



314. The white-pine region begins in North-western Ohio, and ex- 

 tends into the states further north and west. In the interior of Michi- 

 gan, around Sagiuaw Bay, and along both lakes, there were vast 

 bodies of white pine, but much of this has been worked out, and 

 according to careful estimates the supply can not last many years. 



315. In the upper Peninsula of Michigan, in Northern Wiscon- 

 sin, and in Eastern and North-eastern Minnesota, there were also 

 large bodies of timber, generally a mixture of conifers and hard- 

 woods. The forests south of Lake Superior were originally second 

 only to those of the Pacific coast for their density, and the size of 

 their growth. 



316. In Illinois and Southern Wisconsin, and from the Mississippi 

 river westward, the prairies begin to predominate, and the native 

 forests are limited to belts along the rivers and streams. In some 

 parts, these spread out into broad areas many miles in extent, and 

 in others they are mere fringes, that gradually disappeared altogether 

 further west. 



The Rocky Mountain Region. 



317. The sides and valleys of these mountains were in favorable 

 situations covered with coniferous forest trees, sometimes occupying 

 broad areas, and elsewhere of more limited extent. The number of 

 species in this region is not over twenty-eight or thirty, of which 

 the conifers form two-thirds the number in species, and by far the 

 greatest proportion in quantity. The box-elder (Negundo aceroides) 

 and the quaking aspen, are the more important deciduous trees. 



