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UNIVERSITY OF COLORADO STUDIES 



Forest formations of the plains region. — The river-bottom and 

 pine-ridge forests occupy essentially different habitats. Along the 

 water courses there is found a good growth of cottonwoods and willows 

 with occasional box-elders, hackberries, mountain maples and alders. 

 Where the stream has not cut a deep bed, and the ground slopes gently 

 away at the sides, these river-bottom forests may be a quarter or half- 

 mile in width. More often, however, they are much narrower. Along 



Fig. 1. — -Map of Colorado. The continental divide is shown by the heavy dotted 

 line, the front range of foothills by the short horizontal lines. East of the foothills lie the 

 great plains. 



the smaller streams there is frequently a single row of cottonwoods or 

 willows. The pine-ridge forests are on the high ground extending 

 between adjacent streams where they grow in coarse, frequently rocky 

 soil. Good examples of pine-ridge forests are seen along the divide 

 between the South Platte and the Arkansas and also at the edge of the 

 "high plains" in the northeastern part of the state. The trees of these 

 ridges are rock pines and cedars which form scattered groups hardly to 



