The Forest 
—$ 
22,359,000 acres in all. This is about 314 
percent of the total forest in the United 
States. Only five other States have a larger forest 
area. Thirteen million acres of Montana’s forest 
lie west of the Continental Divide, and 9 million 
acres are in eastern Montana. Distribution within 
the two areas, by class of land, is as follows: 
()22850,000 2c of Montana is forest land,’ 
Western Eastern 
Montana Montana’ Total 
(million (million (million 
Class of forest land: acres) acres) acres) 
Gommerciall: Snes sat ee 8.9 6.9 15.8 
Noncommercial24 352 aes 2.5 1.6 4.1 
FRESETVE Cee oh tere oe eee 1.6 9 2.5 
“RO talte-s4 Messe earns ae 13.0 9.4 22.4 
Montana’s forest is neither homogeneous nor 
evenly distributed. For convenience, its distribu- 
tion can be described this way: Where there are 
mountains there is forest. “Ihe mountain ranges 
are mainly in the western two-fifths of the State 
and extend ur a general northwest-southeast di- 
rection, turning eastward along the southern 
border of the State. Where there are extensive low 
areas or prairies, the natural vegetation generally 
is grass and sagebrush, except for thin stringers of 
timber along the rivers and streams. 
West of the Divide, particularly in the north- 
west corner of the State, the rough topography sets 
up conditions that result in more moisture than 
farther east. Because of this favorable 
climatic factor, the forests of western Montana 
cloak 81 percent of the total land area and extend 
over all but the wider valley floors. 
East of the Divide the drier climate holds the 
lower margin of the forest higher on the mountain 
occurs 
° The definition of “forest land” and other Forest Survey 
terms used in this report are in the appendix, pp. 60 to 62. 
Because the terminology differs somewhat from that in 
earlier reports, the definitions should be studied carefully. 
slopes, in some localities 6,000 feet and more above 
sea level. Consequently, most of the timber in 
eastern Montana occurs as a series of islands or 
patches. Figure 14 shows the proportion of forest 
area to the total land area in various parts of 
the State. 
Dercent 
HI 91-100 
RELATION OF FOREST AREA 
7i- 90 
aa TO TOTAL AREA 
m0 
Ticure 14. 
Moisture and temperature also have much to do 
with the great variation of timber types within 
the forest. “These two weather factors are in turn 
related to altitude and exposure. ‘There is an 
11,000-foot difference between the highest and 
lowest points in Montana. 
The Reserved Forest 
One-tenth of the Montana forest (2.5 million 
acres) is reserved and thus unavailable for timber 
use. Most of the reserved area is federally owned 
Jand in Glacier and Yellowstone National Parks 
(933,000 acres) and wild and wilderness areas in 
the national forests (1,588,000 acres). Figure 15 
shows the location of these principal reservations. 
Approximately half of the reserved area (1,070,000 
14 Forest Resource Report No. 5 U. S. Department of Agriculture 
