164 DESCRIPTIVE GEOLOGY. 



crossed in section, dipping conformably westward.^ West of the divide toward 

 Separation Station, the rusty sandstones and arenaceous clays, with their 

 included coal beds, of the Laramie group, are crossed, dipping at first with 

 the lower sandstones 10° to 15°, but beyond the open shallow valley to the 

 north they are seen to lie nearly horizontal, perhaps dipping 2° to 4° north. 

 About two miles to the south of Separation Station, these rocks form paral- 

 lel ridges running northeast and southwest, in which the beds dip 10° to 

 the northwest. The upper sandstones are full of impressions of deciduous 

 leaves, and constitute the characteristic leaf-beds of the Laramie group. 



From Separation, the beds flatten out to the west as well as to the north, 

 and form a,high barren plain country, in which the dry, shallow watei'-courses 

 present but few exposures of rock. One can only distinguish that the strati- 

 fication-lines occupy nearly horizontal planes, but of the character of the 

 beds little definite idea can be formed. It is probable that the Laramie 

 beds occupy the greater part of the surface of this region, though in some 

 coarse sandstones are found plentiful casts of fresh- water shells, Lymncea, 

 Viviparus, Goniohasis, which probably represent the same horizon as the 

 beds found at the junction of the Little Snake River and Little Muddy 

 Creek. They would then be remnants of the Vermillion Creek Tertiaries, 

 which may doubtless at one time have extended as far east as the base of 

 the Rawlings Peak uplift. About ten or twelve coal beds of various thick- 

 nesses can be distinguished in this region. None have been worked on 

 account of the exposed and dry nature of the country; but the compara- 

 tively horizontal position of the strata presents a very favorable condition 

 for the mining of coal on a large scale. 



Savory Plateau Region. — From the depression of Bridger's Pass and 

 the valleys of Sage and Little Muddy Creeks, southward to the base of 

 the Park Range, extends an elevated plateau region, cut through by deep 

 canon-like valleys, the higher portion of which, immediately adjoining 

 these valleys, and which is about 8,500 feet above the level of the sea, has 

 received the name of the Savory Plateau. This region is principally covered 

 by horizontal beds of the North Park Tertiary, which, as proved by exposures 

 in the deeper cuts on its northern edge, overlie the upturned edges of Cre- 

 taceous and earlier beds, while the higher portions of the ridges are capped 



