Rocky Mountain Rambles. 163 



pole pine (Pinus Murrayana), Engelmann spruce (Picea Engel- 

 manii), the Abies lasiocarpa also associated with the latter. 

 There are two additional pines in the Rockies that are similar 

 in aspect, one the limber pine (Pinus flexilis) which is common at 

 higher altitudes where it often gets the full sweep of the wind. 

 The species is common in Colorado in the Uintah Mountains, 

 northward and westward. Its altitudinal range varies from 

 8,000 to 11,500 feet in Colorado, and at lower altitudes in Mon- 

 tana. The white bark pine (P. alhicaulis) is less widely distrib- 

 uted but is not uncommon in northwestern Wyoming, Bitter 

 Root Mountains, with a lower and more rounded head; at higher 

 altitudes it is a dwarf tree. 



In the Bitter Root Mountains of Montana, the adjacent 

 regions of Idaho, and in northern Washington, the P. ponderosa 

 occupies the ridges and slopes along streams at a much lower 

 altitude than in southwestern Colorado where it is found at about 

 8,000 feet. The Douglass fir usually follows, and in the Wa- 

 satch Mountains it may reach 10,000 feet. The species is found 

 near tide level in Washington and Oregon. It is abundant in 

 the Cascades, and here, as elsewhere, it has been found that this 

 species succeeds best on the well drained soils. The thick bark 

 of Pinus ponderosa and Pseudotsuga protects these species from 

 fire. 



Trees of the Abies concolor are abundant in the canvons of 

 the Wasatch Mountains. It is common on the more moist but 

 well drained slopes in the Weber canyon, and the Logan Moun- 

 tains. The lower regions are often covered with white oak 

 iQuercus undulata) which in the Wasatch and the Uintah moun- 

 tains covers thousands of acres. The trees are seldom more than 

 4-6 inches in diameter and 15-25 feet high. In the Wasatch 

 mountains as well as in the Bitter Root Mountains the 

 Ceanothus velutinus is common; the small openings contain a 

 great deal of Balsamorrhiza sagittifolia and in places where the 

 snow lies longer the Weyethia amplexicaulis is abundant. 



(Continued in August Number.) 



