1907] 



YOUNG— FOREST FORMATIONS OF COLORADO 



325 



which were originally pretty heavily timbered; but since the settle- 

 ment of the region^ the forests have been and still are disappearing. 

 The topography of the mountains has been determined by vast 

 elevation accompanied by extensive faulting, and followed by great 

 erosion. The face of the country is exceedingly broken. High, 



4 



Fig. 2.— Foothills near Boulder; the aUitude of the tops of the hills ia the back- 

 ground is approximately 1950^; in the foreground is seen the shrub-grass formation 

 of the foothills, which in this \^e\v is dominated by a grass-sagebrush society; scattered 

 over the hills in the background is Finns scopiilorum, 



rocky ridges alternate with deep canons walled in by rocky precipices 

 hundreds of feet in height, Avith an occasional granite dome isolated 

 from the general mass. Such a dome is shown in fig, i. 



Passing from the plains westward toward the Continental Divide, 

 we first encounter the foothill region of the main range {fig. 2). This 



o 



is a region of broken ridges with steep slopes, cut at intervals of 1.5 



