THE MANAGEMENT OF LODGEPOLE PINE 

 By D. T. Mason 



Lodgepole pine (Pinus contorta) is the most important tree of 

 that portion of the Rocky Mountains included in northern Colo- 

 rado, Wyoming, central and southwestern Montana, northeastern 

 Utah, and southeastern Idaho — often called the "Lodgepole re- 

 gion." The species also occurs in sufficiently well developed 

 stands to be of more or less commercial importance in western 

 Montana, northern Idaho, Washington, Oregon, and California. 

 The "Lodgepole region" is, of course, mountainous, but fre- 

 quently interrupted by bro^id, open valleys or plains. The for- 

 ests are confined to the mountains, where there is sufficient precipi- 

 tation to permit tree growth. Practically all of the forest land 

 of the Lodgepole pine region is included in 25 National Forests 

 and the Yellowstone National Park, an area of about 37 million 

 acres. 



Lodgepole has an altitudinal range in northern Colorado ex- 

 tending from about 7,000 feet to about 11,500, and in central Mon- 

 tana from about 4,500 to about 9,000 feet. Within this range well 

 developed stands occur in a belt from 2,000 to 2,500 feet wide. 

 In such stands, at about the age of 140 years, most of the trees 

 are from 7 to 13 inches in diameter and from 60 to 80 feet tall. 

 The species characteristically forms dense, even-aged stands of 

 tall, slim trees with comparatively narrow crowns. It rarely 

 occurs where the annual precipitation falls below 18 inches, and 

 well developed stands generally enjoy a precipitation ranging from 

 21 to 30 inches. The tree is not fastidious as to soil if there is 

 enough moisture present ; the best growth is made on deep, fresh, 

 well-drained soil. Temperature extremes from plus 100° F. to 

 minus 55° F. are endured. The growing season is short, averag- 

 ing from three to four months ; in the Lodgepole zone killing 

 frosts usually occur every month in the year. The mean annual 

 temperature is about 35° F. The mean annual snowfall varies 

 from 100 to 250 inches; and snow usually lies on the ground 

 continually for a period of from five to seven months. For the 

 region the prevailing winds are westerly. 



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