POST-CRETACEOUS HISTORY OF WESTERN WYOMING 209 



to differential warping; but they do not preclude the possibility 

 of warping in a minor degree. 



The hypothesis that existing conditions are due to uniform 

 regional uplift followed by selective denudation is the only one 



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Fig. 22. — Diagrams illustrating the possible origin of the existing Wind River 

 plateau as a horst, an unwarp, or an erosion remnant. 



against which I find no serious objections. It agrees well with 

 the fact that remnants of the peneplain now exist only upon the 

 outcrops of the hardest rocks, and with the other fact that these 

 remnants now stand at a more or less common elevation. The 

 hypothesis of regional uplift is therefore accepted tentatively. 



