94 DESCEIPTIVE GEOLOGY. 



SECTION III. 



MEDICINE BOW EANGE. 



BY ARNOLD HAGUE. 



Physical Description. — The Medicine Bow Eange may be considered 

 the second great range of the Rocky Mountain system. It extends from 

 about the latitude of 40° 15' northward to latitude 41° 40', with a trend 

 approximately northwest and southeast. The eastern slope borders on, and 

 is closely connected with, the Colorado Range for some distance, but grad- 

 ually trends off more to the westward, and forms the western rim of the 

 Laramie Plains. The western side of the range shuts in the North Park on 

 the east and north, and still farther northward forms the boandary of the 

 North Platte Valley, which lies between it and the Park Range. As thus 

 defined, the Medicine Bow Range is about 100 miles in length. In width, 

 it varies very considerably, the southern end only measuring 10 or 12 miles 

 from east to west, but across its broadest expanse, in the region of Medicine 

 Peak, it reaches 30 to 35 miles. 



The highest peaks in the range are : Mount Richthofen, at the southern 

 end, nearly 13,000 feet high ; Clark's Peak, at the northeast corner of the 

 North Park, 13,167 feet; Medicine Peak, 12,231 feet; and Elk Mountain, 

 11,511 feet, at the extreme northern end, which stands out boldly as a 

 prominent landmark, somewhat isolated from the rest of the range. 



South of Mount Richthofen its trend is nearly north and south, a nar- 

 row serrated ridge, with short but deep glacial canons putting out both east 

 and west. Mount Richthofen rises above the surrounding peaks 800 or 900 

 feet ; and from the Park Basin looking eastward, its summit presents a rug- 

 ged, irregular mass of granite, with graceful outlines. North of the peak, 

 the strike of the rock changes to a few degrees west of north, and it is of 

 special interest that just where the change of strike sets in occurs the great 

 flow of rhyolite that covers the v/estern base of the range ; the greater 



