554 EEPORT UNITED STATES GEOLOGICAL SURVEY. 



down both strikes on the map, it seems probable that they connect the 

 two locaUtes. 



Croto Creel'. — Crow Creek rises opposite the head of Preuss Creek. 

 It receives its water mainly from the eastern side of the Preuss Eange. 

 In this portion of its course the creek flows northward. The range on 

 the west is comiDosed of Carboniferous limestones in almost vertical 

 position, dipping about 80° or 85° to the eastward. On the east side of 

 the creek occur the beds that have been noted on Beaver Creek. The 

 relation between them and the limestones of the range could not be de- 

 termined. I think that between Beaver Creek and Crow Creek there is 

 a synclinal and perhaps an anticlinal. On receiving a large branch from 

 the Preuss Eange, Crow Creek turns eastward, and soon crosses the anti- 

 clinal of the head of Beaver Creek. A few miles below, two creeks come 

 in nearly opposite each other. The one from the south occupies the 

 synclinal noted at the two locations made in the bend of Beaver Creek. 

 Between this point and the valley of Salt Eiver there are two anticlinals 

 and a broad synclinal. The eastern anticlinal forms a rounded hill 

 facing Salt Eiver Yalley. It is composed of greenish-gray sandstones. 

 The section from this hill to the beds of the central portion of the anti- 

 clinal is the following : 



Section No. 18. 



1. Greenisli-gray sandstones with bands of shale. 



2. Purplisli and reddish sandstones. 



3. Conglomerates. 



4. Red sandstones. 



5. Gray shales. 



The red sandstones, 'So. 4, and conglomerates, Ko. 3, are probably the 

 same as noted on Beaver Creek. 



On the north branch of Crow Creek the conglomerates dip eastward 

 on the east side. On this creek, near the main stream, there are remnants 

 of old spring deposits forming dams of calcareous tufa across the creek. 

 The beds on the west side dip west. On a station at the south end of the 

 ridge, Mr. Mushback observed limestones, probably Carboniferous ; and 

 on a station north of this, but probably east of the axis line of the ridge, 

 Mr. Gannett noted sandstones, but of what age I could not determine. 



The valley on this branch of Crow Creek is broad and well grassed. 

 A number of small branches come in from the west. 



SmoTcmg GreeTi. — This is the only large branch of Salt Eiver not yet 

 described. It drains the country north of Crow Creek, and consists of 

 two principal branches, one coming from the north having its sources 

 opposite those of the Blackfoot Eiver, and the second coming from the 

 south through a broad valley similar to the one on the branch of Crow 

 Creek last described. When these two streams unite the direction is 

 changed to east, and the stream formed forces its way to Salt Eiver 

 through a caiion cut in low rolling hills. It is in this region that the 

 salt beds occur, from which Salt Eiver derives its name. On the west 

 side of Salt Eiver, below the mouth of Smoking Fork, there are salt flats, 

 and where the two branches of the latter stream unite above the canon 

 there are numerous salt springs. Here is where the old salt works were 

 located, at the poiut where the old Lander road crosses the creek. 



In the bluff east of this place red and gray sandstones are seen dip- 

 ping eastward. The reddish beds are below, and seem to be the ones 

 from which the salt is derived. Farther east an anticlinal fold was seen. 

 This region was not thoroughly explored, as time did not permit our 

 going through these hills. The evident structure, however, is a series 



