LODGEPOLE-PINE FORESTS OF BOULDER PARK 267 



In the southwest end of the park on the slope facing to the north 

 the pine forest occurs only at the top ot the mountains. Below this 

 and to the east is a large burned-over area. This is conspicuous 

 because of the bare trunks of dead trees that tower above the young 

 aspens. The central part of this slope is covered by an open forma- 

 tion of lodgepole pines, more dense toward the eastern end of the slope. 

 Among the pines in the open formation are young spruces and firs 

 and small societies of aspens. On dry, exposed places a few limber 

 pines invade the forest. On this same north-facing slope at the east- 

 ern end of the park there is a well-developed forest of pines, firs and 

 spruces. 



The vegetation of the south-facing slope (i.e., the northern bound- 

 ary of the park) is abundant and of greater variety. Here there are 

 meadows, alder-willow thickets, aspen groves and pine forest. At 

 the eastern end there is a large pine forest, which farther to the west 

 is replaced by an aspen grove. This grove covers the entire central 

 portion at the base of the Giant's Ladder. In the aspen grove there 

 are large areas of grassland and associations of scrub willow and alder. 

 Throughout the grassland are scattered various species of flowering 

 herbs such as Delphinium, Aconitum, Helianthella, Erigeron, Cam- 

 panula, Galium and Mertensia. From the summit of the Giant's 

 Ladder a lodgepole-pine forest extends down to the western end of 

 the park. On the north-facing slope to the west of the park is a 

 close formation of firs and spruces among which are scattered a few 

 lodgepole pines. 



The Climax Formation. — The lodgepole pine, Pinus murrayana 

 "Oreg. Com.," forms the climax formation at Boulder Park. It 

 is a tall, straight tree, in this locality attaining a height of almost 

 60 feet. The diameter of trees 55 to 58 feet in height may vary 

 from 9 inches to 22 inches. No trees over 22 inches in diameter were 

 noted. It is probable that none of the lodgepole-pine trees of this 

 locality are over 150 years old. Successive forest fires have ravaged 

 the locality, a most serious one about forty years ago killing most 

 of the lodgepole pines which were standing at that time. Here and 

 there, however, certain groups of trees escaped; some trees were 



