CEETAOEOUS UPLIPT OF OYSTER EIDGE. 253 



Along the line of the railroad, Cretaceous strata are again found exposed 

 near Aspen Station. Here are several hundred feet of bluish clay beds filled 

 with fish-scales and occasional impressions of bones and teeth, in which also 

 some fragments oi Ammonites were found, while intercalated in the clay beds 

 are occasional beds of grayish limestone. These beds dip at an angle of 

 10° to 15° to the westward, and are overlaid on the summit of the ridge 

 by a considerable thickness of white and gray sandstones, in which are 

 found the Ostrea soleniscus of Oyster Ridge, for which reason they have 

 been referred to the Fox Hill group, while the underlying clays undoubt- 

 edly belong to the Colorado series. All these beds have a close connection 

 with the Cretaceous exposures on the west side of the divide near Bear 

 River City, which will be seen represented on Map III. 



