GEOLOGICAL SURVEY OF THE TERRITORIES. 139 



side, inclining at a moderate angle, at first 15°. On the north side 

 there is a plain, synclinal valley, extending off to the southwest. Pass- 

 ing across this anticlinal, we come out into an expansive, valley-like 

 plain, with a long cretaceous ridge extending off to the southeast, while 

 on the north side there is a low ridge of sandstone, with the strata again 

 inclining to the northeast and trending to the northwest, thus forming 

 an open sage plain. The formations on the north side are mainly the 

 coal-bearing strata, with cretaceous clays cropping out at the base. On 

 the south side the cretaceous beds seem to extend off to the southward 

 as far as the eye can reach. In the distance the ridges which form the 

 high hills near Bridger's Pass are distinctly visible, so that it is easy 

 to connect our south belt of exploration with the middle one. It be- 

 comes still easier west of Separation, where the beds of the Washakie 

 group are nearly or quite horizontal, and extend undisturbed across the 

 country for nearly one hundred miles, from the Seminole and Sweetwater 

 ranges on the north to the high hills of Bridger's Pass and the ranges 

 to the southwest. The lower eocene, or coal beds, seem to dip from the 

 mountains to the southward, if we glance across the country south of 

 the road; and gradually to the north of the road they flex around so 

 as to incline from the Seminole and Sweetwater Mountains. As usual, 

 the lower tertiary beds are quite variegated in color — yellow, rusty-yel- 

 low, rusty -brown, and drab — presenting an exceedingly uncomely look. 

 In the distance to the north the Semiuole range can be seen quite clearly, 

 with a trend about northwest and southeast. 



Near Separation, about ten miles west of Eawlings' Springs, a coal 

 bed eleven feet thick has been opened, probably the same as the one 

 opened at Carbon, and near Rock and Cooper Creek. The clip is nearly 

 west about 10°. The opening being at the summit of the hill, all the 

 coal will have to be drawn up a slope, and the difficulties of drainage 

 will be greatly increased. The coal is of excellent quality. Above and 

 below the coal is the usual drab indurated clay. Below the clay is a bed 

 of gray ferruginous sandstone. 



On the summits of the hills in the vicinity are layers of fine-grained 

 siliceous rocks with arenaceous concretions, some of them containing 

 impressions of deciduous leaves. 



The tertiary beds lie in ridges running across the country. The beds 

 are uplifted in every direction. A more desolate region 1 have not seen 

 in the West. Nothing seems to grow but sage bushes, and in some of 

 the valleys they grow very large. All over the surface of the hills and 

 in the plains are great quantities of water-worn pebbles. Many of these 

 valleys were scooped out by an amount of waters far in excess of any 

 known at the present day in this region. Some of the widest and deep- 

 est do not now contain any running stream. 



The layers of fine-grained sandstone on the hills in this vicinity con- 

 tain more or less impressions of leaves, like Populus and Platanus, in a 

 good state of preservation. 



West of Separation the dip of the tertiary beds diminishes. Before 

 reaching Creston, about thirteen miles west of Separation, they lie nearly 

 horizontal, and all the surrounding country presents more the appear- 

 ance of a plain. At that station the Union Pacific Railroad Company 

 have unk a well one hundred feet or more deep. At a depth of eighty- 

 three feet, the workmen passed through four feet of excellent coal 

 and four feet of coaly shale. The coal was of about the same 

 quality as that near Separation, probably from the same bed. If so, 

 coal at a depth of about eighty feet must underlie an area of at least 

 one hundred square miles. In this well, beds of bluish, arenaceous clay 



