STRATIGRAPHICAL REPORT. 



49 



a scanty growth of sage-brush and grease-wood, and are covered here and there 

 with deposits of sand and gravel, mingled with quartz pebbles, bits of smooth 

 sandstone, and water-rolled fragments of jasper and flint. The streams flow 

 between steep banks. The low buttes that lie along the foot of the mountains 

 are weathered into fantastic shapes, while the excavations, whose bottoms are 

 many feet below the plains, wear the usual features of erosion : deep caflons, 

 ravines, smoothed mounds, and tall columns of sandstone. 



The description hereafter and the section which follows relate wholly to the 

 Bridger beds as they are exposed in the Washakie basin. The position of this 

 basin and the relation of these groups of rocks, the Vermillion Creek, the Green 

 River, and the Bridger, can be clearly understood by referring to the sketch- 

 map. At this point the Bridger beds form a central island surrounded by a 

 ring of Green River beds, widest towards the South, and these beds are flanked 

 by the Vermillion Creek (lower Eocene) beds. This map is from King's sur- 

 vey. All the stratigraphical sections and measurements of this report were the 

 work of the Princeton party. 



Standing on the plain at the edge of one of these excavations and looking 

 down, the scene that presented itself cannot well be described. The eroded 

 area was in three immense basins, each succeeding one smaller and lower than 

 the other, so that, seen from a distance, the Bad Lands had much the appear- 

 ance of a great amphitheatre. The bottom of the lowest basin, stretching away 

 until it was lost to sight, was the arena. The two benches separating the three 

 basins were the tiers of seats. 



From the plain to the bed of the first basin the face of the rock was almost 

 vertical, yet very irregular and broken. At places long thin masses jutted out. 

 At others the wall was cut into deep recesses or broken through by narrow 

 cafions that wound and twisted, crossed and recrossed, and finally ended in a 

 well-shaped excavation. On the bottom of such wells was to be seen every form 

 of erosion — pyramids, cones, mounds, and table-like platforms — while here and 

 there stood up isolated, or in clusters of two or three, tall columns of sandstone, 

 each capped by a slab of hard, coarse brown sandstone to whose protection it 

 owed existence.. Out from the walls stood small buttes ; some had steep sides 

 and broad flat tops, but most of them were broad at the base and ended, a hun- 

 dred or more feet above, in a sharp edge not two feet wide. 



While searching in the Leclede Bad Lands for fossils a careful examination of 

 the beds was made and two geological sections taken. The profiles of these, 

 drawn to a scale of three feet horizontally to one foot vertically, are shown in 

 the accompanying plate. That marked No. 3 was run by prismatic compass 

 due East across the Bad Lands from a point some five miles to the South of 

 Haystack Mountain. The eastern direction was chosen because, in general, 



