52 Forest Club Annual 



From the fact that Nebraska is mostly a prairie state 

 many people are commonly of the opinion that our state is a 

 level or rolling plain throughout. A trip to the northwest 

 would quickly and effectively remove this mistaken impres- 

 sion. In Northern Sioux and Dawes counties the gently 

 undulating grass-covered surface of the high plains suddenly 

 gives way to a topography characterized by deep, rocky 

 canyons and towering walls with dome-shaped rocks and per- 

 pendicular sides, and a conspicuous arborescent vegetation in 

 which Pinus ponder osa is the most evident tree species. I shall 

 deal in this paper mainly with that portion of this region 

 known as "Pine Ridge" as it occurs in Sioux county, although 

 the region with its pine clad slopes extends as a narrow tongue 

 for many miles farther eastward. 



Geologically the region under discussion is a portion of 

 the Arikaree formation. The gray or buff colored calcareous 

 sandstones of this formation are everywhere conspicuous 

 either as flat-topped ridges, towering walls and pinnacles, or 

 steep talus slopes. The rock is 'only slightly stratified. Their 

 bedded nature is most evident near the top of the formation 

 as it occurs here, but in most places the stratification is not 

 at all evident. A honey-comb rock structure with many pro- 

 truding fossils or flinty projections is very common and con- 

 spicuous throughout the region. Through this rather soft and 

 easily weathered rock many canyons have been cut. Such 

 canyons usually extend in a northerly direction from their 

 heads in the High Plains for from two to six or more miles 

 through the rock and emerge into the low r lands or Bad Lands 

 north of "Pine Ridge" several hundred feet below the table 

 lands to the southward. From the northern face of the series 

 of ridges these canyons with their streams converge in the 

 Hat Creek basin, draining by means of this stream toward the 

 northeast. The standstone has fallen down from the sides of 

 rugged cliffs and buttes, often towering several hundred feet 

 above the canyon bottoms, to such a degree that steep talus 

 slopes are everywhere present. Tn fact "Pine Ridge" is not a 

 ridge at all, but may be more accurately described as an 

 escarpment extending as a narrow tongue for about half the 

 distance across the northern portion of the state, which is com- 

 posed especially in the west, of a succession of short north 



