THE NORTH PARK. 129 



Bow Range as far as Elk Mountain, and around the northern end of tlie 

 Park Range. At the upper end of the valley, south of Grand Encampment 

 Creek, they are quite thin, but appear to thicken northward. 



On the lower geological section given on Map I may be seen the rela- 

 tion of the North Park and its sedimentary beds to the Archaean uplifts. 

 The section is drawn through Crawley Butte, near the broadest expanse of 

 the Park, and represents all the Mesozoic formations resting upon the Medi- 

 cine Bow Range, and passing undei* the North Park Tertiary deposits, 

 which lie horizontally against the Archaean island. To the west of Crawley 

 Butte, the Dakota and Colorado Cretaceous alone, of the older series, come 

 to the surface along the Park Range. 



9 D G 



