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2) USDEPARTNENT OFACRICULTURE © 9 
RA No. 154 
Contribution from the Forest Service, Henry S Graves, Forester. 
January 14, 1915. 
THE LIFE HISTORY OF LODGEPOLE PINE IN THE 
| ROCKY MOUNTAINS. 
By D. T. Mason, Assistant District Forester, District 1. 
GEOGRAPHIC DISTRIBUTION AND ALTITUDINAL RANGE. 
Lodgepole pine (Pinus contorta Loudon) is one of the most widely 
distributed western conifers. Its botanical range, shown in figure 1, 
extends from the Yukon Territory southward through the Cas- 
cade, Sierra Nevada, and San Jacinto Mountains to northern Lower 
California, and through the main range of the Rocky Mountains 
to northern New Mexico. Its commercial range, however, is much 
more restricted. At present lodgepole is being lumbered exten- 
sively only in Montana, Wyoming, Colorado, and the Uinta Moun- 
tains in northeastern Utah. Large areas also occur in Idaho, Wash- 
ington, Oregon, and California, but in these regions the tree is 
rendered less important commercially by the presence of other and 
more valuable timber trees. 
The “lodgepole region ”—that in which lodgepole is the preemi- 
nently important species—is mountainous, frequently interrupted by 
broad, open valleys, or plains, partly fertile and devoted to farming, 
and in part suitable only for grazing. The forests, as a rule, are con- 
fined to the mountains. 
The altitudinal range of lodgepole pine in the Rocky Mountains 
decreases from south to north. In Colorado and southern Wyoming 
the tree is found at altitudes ranging from 7,000 feet to timber line, 
or 11,500 feet; in northern Wyoming at from 6,000 to 10,500 feet; and 
in southwestern and central Montana at from 4,500 to 9,000 feet. As 
a rule, however, it forms commercial stands only within an altitudinal 
belt from 2,000 to 2,500 feet in width. In Colorado the best stands 
are usually between 7,500 and 9,500 feet; in Wyoming between 7,000 
and 9,000 feet; and in southwestern and central Montana between 
6,000 and 8,500 feet. In the more humid northwestern portion of 
_ Montana, outside of the main lodgepole region, the species grows at 
62799°—15—1 
