1 98 ELIOT BLACKW ELDER 



surface, surrounded by many low hills and even mountains of gentle 

 slope, rising to a distinct divide now marked by the crest of the 

 Wind River Range. Unmarred remnants of this surface are be- 

 lieved to exist still in Goat Flat, the high plateau west of West 

 Torrey Creek, the flats both north and south of Clear Creek and 

 other similar features ranging from about 12,000-13,000 feet in 

 altitude, and declining near the outer borders of the range to about 

 11,300 feet. As a result of two or three stages of glaciation, the 

 slopes of the once broad, residual hills and especially the axial 



Fig. 16. — Residual soil from granite, a remnant of the Wind River peneplain, 

 now at 11,300 feet, Gypsum Creek. 



divide have been excavated and made much steeper than before. 

 To this process I ascribe the existing sharpness of the peaks and 

 aretes of the range. The broad plateau remnants at 10,000- 

 10,500 feet east of Pinedale may not be parts of the summit pene- 

 plain, but rather the result of a later cycle. 



Although the ancient peneplain has since been widely demol- 

 ished by erosion, other remnants of it than the Wind River plateau 

 should exist; but a search of neighboring ranges brings unsatis- 

 factory results. The Mount Leidy highlands, to the northwest, 

 are so maturely dissected that no ancient fiats remain at high eleva- 

 tions. The flats at 11,000-12,000 feet in the Absaroka Range 



