GEOLOGICAL SURVEY OF THE TERRITORIES. 



137 



The view is taken from the tertiary hills bordering the Missouri Eiver, 

 near the mouth of the Yellowstone, hut is typical of the "bad lands" 

 all over the West where this formation prevails. The little streams 

 formed from the drainage of the hills cut deep gorges into the soft 

 superficial deposits at their base, and frequently produce great obstruc- 

 tions to trains of wagons. 



Fig. 11. 



As we move on west of Fort Steele, we can see on the north side the 

 outcropping beds of sandstone. About three miles west of the North 

 Platte this ridge gradually bends off toward the northwest. The cre- 

 taceous clays of No. 4 are weathered so that the surface has a smoothly 

 rounded appearance, and the anticlinal beds expand out into a broad 

 plain. The anticlinal extends a little east of south toward Pass Creek. 

 The erosive forces seem to have come from the southeast, between the 

 detached fragments of the Medicine Bow range, and extended across 

 the country toward the northwest. West of Fort Steele the road passes 

 along an anticlinal valley for about two miles ; it then enters a mono- 

 clinal valley and continues for six or eight miles ; then it cuts through 

 cretaceous ridges which incline northeast. Before reaching Bawlings's 

 Springs the red beds are exposed on the north side of the road about a 

 mile distant. These anticlinals seem to pass across the intervening 

 country, connecting the ranges of mountains south with those far to the 

 north. It is only here and there that rocks older than the cretaceous 

 or tertiary are exposed by them, until we come into the vicinity of 

 some important range. But at Bawlings' Springs all the formations 

 are exposed over a restricted area, from the granites to the cretaceous 

 inclusive. The elevating forces were exerted more powerfully here than 

 at any other point along the railroad from Laramie Station to the 

 Wasatch Mountains. To the south of the road are variegated gray, 

 brown, and reddish siliceous rocks dipping 5° to 10° southwest. A very 

 hard, bluish limestone resting upon them I have no doubt is carbonifer- 

 ous, although I was unable to find any fossils in this region. North of 

 the road ridges of upheaval stretch away toward the northwest, and at- 

 tain a height of twelve hundred to fifteen hundred feet above the road. 

 On careful examination the red syenite may be found exposed in a num- 

 ber of places, and gives us the opportunity of studying the relation 

 which the unchanged rocks sustain to the nietaniorphic. The syenite 

 beds dip 70° about southeast, the unchanged beds resting upon them 

 in nearly a horizontal position. The layers immediately on the syenite 



