liEGION EAST OF THE UINTA RANGE. 277 



of the upturned Cretaceous could have been found in other stream-beds to 

 the north had time permitted more extended exploration. The thickness of 

 conformable beds, thus exposed from the Carboniferous upwards, cannot be 

 less than 10,000 to 12,000 feet. 



The upper portion of the basin of Vermilhon Creek is, as we 

 have seen, a bench-country, intersected by innumerable dry water- 

 courses cut through the horizontal lower beds of the Vermillion Creek 

 series, bounded on the northeast by a line of blujffs extending southeast- 

 ward from Pine Bluffs, and on the southeast by the line of Vermillion 

 Bluffs, in which were recognized, as already stated, the upper red beds of 

 the Vermillion Creek series, the limy shales of the Green River series, and 

 a remnant of the Wyoming Conglomerate; the two former dipping to the 

 southeast. Near the summit of the ridge, which extends to the southwest 

 from Vermillion Creek Canon, where the Tertiary beds have been removed, 

 are found a few exposures of coarse red sandstone, which have been, from 

 their position, referred to the Triassic, though lithologically they resemble 

 very closely the Weber Quartzite. The summit of the ridge is, as has been 

 seen, covered by a small remnant of coarse conglomerate beds, resembling 

 the Wyoming Conglomerate, to which they have been provisionally referred. 



East of this point, with the exception of the little outcrop of limestone 

 and sandstone north of East Mountain, the northern member of the Uinta 

 fold appears to be completely concealed by the Tertiary beds, which have 

 filled the great depression of Brown's Park, The regular line of Weber 

 Quartzite cliffs, which wall in this valley on the south, and whose beds have 

 a uniforai and gentle inclination to the southward, may be considered as 

 properly belonging to the southern member of the main Uinta fold. Before 

 proceeding to the description of this southern member, a brief sketch will 

 be given of the structure and geology of the 



Region East or the Uinta Range.— On the extreme southeastern 

 corner of the map, the Cretaceous coloring covers the western continua- 

 tion of the rolling, grassy country of the upper valley of the Yampa of 

 Map I, in which few rocks are exposed on the surface, except in the canons 

 of the streams, notably that of the Yampa River itself. The general struct- 

 ure of this region is that of a series of gentle folds, having a north and south 



