THE FOSSIL FIELDS OF WYOMING 



feet elevation. The hills just south of Como rise 400 feet above 

 the plain, caused by uptilting of strata. Within ten miles north 

 of Medicine Bow, hills appear on the left and twenty miles 

 north we are in the Freezeout Mountains; a few miles farther 

 are the Freezeout Hills. By quaquaversal upthrusts this 

 region has been thrown up and tilted so as to form beautiful 

 anticlinals, bringing to view the Triassic and Jurassic, capped 

 by Dakota Cretaceous. Viewed from several miles east, the 

 Freezeout Mountains present an interesting panorama, the strata 

 toward the southeast end dipping southeast, while that south a 

 few miles off dips south, with the central portion very much 

 eroded, the whole a beautiful illustration of an anticlinal valley . 

 The eroded hills, formed of Jurassic beds capped by Dakota 

 sandstone, afford picturesque scenery near Rock Creek, Little 

 Medicine and the Freezeout Hills northwardly to the Seminole 

 Mountains. In this region are beautiful exhibitions of anticlines, 

 synclines, faults and erosion. The plains are mostly underlaid 

 by later cretaceous. The Dakota group consists chiefly of 

 sandstone. The Fort Benton group is chiefly clay shales with 

 fish scales and teeth. The Niobrara crops out in the lower hills 

 of the plains. The Fox Hills group consists chiefly of sandstone 

 and shales with some hard concretionary masses of calcareous 

 sandstone, often containing fossil moUusca. 



The Laramie Plains are traversed by tributaries of the 

 North Platte, including Laramie, Rock Creek and Medicine 

 Bow, all swiftly flowing streams, with an abundant supply of 

 clear, cool water. These streams all originate m the Medicine 

 Bow Range. Occasional small lakes occur on the plains; 

 Cooper's Lake is the largest. Como is also a pretty body 

 of water. Some of the lakes contam valuable deposits of soda. 



