TEALE.l DESCRIPTIVE GEOLOGY GREEN RIVER BASIN. 527 



far as Labarge Creek, however, the Wahsatch Group forms the largest 

 part of the surface west of Green Eiver. There is a dip to the eastward, 

 so that on the east side of the Green the Green Eiver beds form the top 

 of the bluffs. The Wahsatch beds disappear a short distance below the 

 mouth of Labarge Creek and from that point southward the caiion is 

 in the Green Eiver beds. This is due to the fact that the beds incline 

 slightly to the southward and eastward, and the direction of the Green 

 is also" in general towards the southeast in this portion of its course. 

 North of the Fontenelle the general course of the Green is south. There 

 are two deviations from this ; one is to the eastward in the valley where 

 it is joined by Horse Creek, and the other is a bend to the westward, 

 above the mouth of White Clay Creek. On the east, bluffs extend 

 along the entire course of the river, but the western wall is broken down 

 wherever a stream enters. The valley bordering the river is always 

 narrow and generally canon-like. Its agricultural capacity will be fully 

 discussed by Mr. Gannett in his report. 



The streams coming into the Green from the west, commencing at the 

 north, are as follows: Lead Creek, Horse Creek, Marsh Creek, White 

 Clay Creek, Bitterroot Creek, Piney Creek, Feather Creek, Labarge 

 Creek, Fontenelle Creek, Slate Creek, and Ham's Fork. I shall take 

 these up in the order given above, reserving the description of their 

 sources until I consider separately the ranges in which they rise. 



Lead Creel:. — Only the mouth of this stream falls within the limits of 

 our district. Xorth of this creek the country appears to be well grassed, 

 and wheu we were in there was full of antelope. Between Lead Creek 

 and Green Eiver is a butte about 400 feet high. Yellow sandstones 

 outcrop low down in this butte and on the edge of Green Eiver, but 

 whether they are of the Green Eiver Group or Wahsatch it is almost 

 impossible to say. A little farther south the character of the Wahsatch 

 beds appears to resemble thaf of the lower part of the Green Eiver 

 Group. On the map I have colored the Green Eiver Group as capping 

 the summit of the butte on which Station 12 is located. It, however, 

 extends westward but a short distance, the Wahsatch beds soon forming 

 the surface and rising on the hills that lie to the eastward of the Wyom- 

 ing Eange. The country between Lead Creek and Horse Creek is com- 

 paratively flat, with a slight slope from the hills toward the east. 



Horse Creelc. — This stream does not extend into the Wyoming Eange, 

 but has its origin among the high hills that lie to the eastward of its 

 northern end. These hills are composed mainly of greenish and yellow 

 sandstones that are of probable Laramie age, and on these beds rest un- 

 conformably the variegated conglomerates and sands of the Wahsatch. 

 Between the hills and the mountains is a rough-like depression, from 

 which on the west rises the bluff face of the Wyoming Eange. Horse 

 Creek is formed by two principal branches, to the southern of which we 

 gave the name of Lynx Creek. Both streams have very straight eastern 

 courses, and until they reach the Green Eiver Basin proper are in caiion. 

 These caiions are cut across a series of folds in the Laramie (?) sandstones 

 and underlying beds. One of our stations, No. 50, was between the forks 

 of Lynx Creek. It was on one of the several buttes that are capped 

 with a conglomerate considered to be a part of the Wahsatch Group. 

 This conglomerate is composed of rather fine quartz, the pebbles and 

 larger masses of limestone, the latter containing traces of Carbonifer- 

 ous (?) fossils. The pebbles are angular, and were evidently derived 

 from the range that rises to the westward. The inclination of the beds 

 is to the eastward, and on some of the neighboring buttes the angle is 

 as high as 20°. The sandstones on which these conglomerates rest, dip 



