226 Annals of the Carnegie Museum. 



some hard as flint. The latter contains leaves of conifers (^Seqiioia) 

 and deciduous trees. 



Near the base of Black Butte are rather soft shales and one very 

 thick seam of lignite. Higher up there are sands and soft clays of a 

 brownish color. Still higher is a series of light gray^andy clays, con- 

 taining brown iron-stained concretions. Near the top is a thick 

 heavy layer of hard sandstone. As before stated, the strata of Black 

 Butte belong to a higher level than those of the bad-lands along the 

 Little Missouri River. 



I did not measure the height of Black Butte, but I judge that it is 

 about three hundred to four hundred feet higher than the surrounding 

 plain. On the west side of the butte land-slides have occurred, and 

 huge blocks of the hard sandstone, which caps the butte, have tumbled 

 down from the cliffs, and are heaped on the terraces and scattered on 

 the slopes in great confusion. Vegetation grows luxuriantly between 

 the rocks. There are clumps and groves of the quaking aspen {Popu- 

 Itis tremuloides^ , a tree not very common in this region. 



From the top of this butte on a clear day a vast tract of country 

 can be seen, extending forty miles or more in nearly every direction. 

 Beginning about twelve or fourteen miles to the northward are the 

 bad-lands of the Little Missouri River, the gray cliffs and slopes 

 of which appear to be higher than the position of the spectator ; 

 but this is true in appearance only. On the west side of the Little 

 Missouri River, overlooking the bad-lands, stands Bullion Butte, 

 and in the further distance Sentinel Butte, which lies south of the 

 railroad station of that name. To the westward is a peculiar prairie 

 with lines of rounded hills, hogbacks, and ridges, and projecting above 

 them, one lone butte, which on account of its form is called " Round 

 Top." When the sun is low and the hills cast their deepest shadows, 

 these elevations seem like the great waves of some mighty ocean, 

 dwindling into faint ridges on the verge of the horizon. Toward the 

 southwest are the Twin Buttes, two elevations which are nearly alike 

 in form and size. Southeastward the prairie is more nearly level, but 

 in several places long lines of flat hills (mesas) can be seen. Far 

 away on the horizon are the Cave Hills. To the eastward across the 

 valley of Sand Creek is a range of hills and bluffs called White Butte. 

 Portions of this elevation are nearly bare and are light gray, weath- 

 ering into bad-land forms. North of east beyond White Butte are 

 the two Rainy Battes. Nearly all the buttes which can be seen, ex- 



