Pool: THE VEGETATION OF THE SANDHILLS OF NEBRASKA 203 



The Loup River system thus constituted is the only important 

 drainage outlet from the sandhills to the south or east. Blue Creek 

 in Garden County is a small, clear stream which drains a small por- 

 tion of the region toward the southwestern limits. To the north, 

 however, there are numerous short streams of considerable volume 

 which rise in the sandhills and follow a northerly course to the 

 Niobrara River. The latter river, the second stream in the state 

 in size, skirts the sandhill region on the north. The tributaries 

 from the south are mostly of the nature of the "springbranches" of 

 Pound and Clements (57). The largest and most important tribu- 

 tary of the Niobrara is the Snake River. This stream rises in 

 eastern Sheridan County and flows eastward through the sandhills 

 parallel with the Niobrara for two thirds of the distance across 

 Cherry County, then turns abruptly northward and finally meets the 

 Niobrara about twenty miles west of Valentine. Along portions of 

 its course this river has cut a deep gorge into the underlying bed 

 rock. The river bed is here very uneven and the fall of the stream 

 great so that in those portions the stream is turbulent and swift 

 and characterized by rapids and falls after the nature of a piedmont 

 or mountain stream. 



All streams of the sandhills exhibit a remarkably even flow of 

 clear water. During extremely dry seasons when the precipitation 

 falls below normal and when evaporation is excessive, the volume 

 of these streams is said to vary considerably. Ordinarily, however, 

 the water table is rather high and there is an abundance of water 

 delivered from the sand to the innumerable large springs that char- 

 acterize the headwaters and the courses of all the streams, so that 

 one of the most striking features of the sandhills is the remarkably 

 uniform flow of their rivers. Some of the feeding springs of the 

 Dismal are noteworthy for their large delivery and because of a 

 distinct rumbling noise as the water boils up in a basin sometimes 

 a yard or more in diameter and to a height of several inches above 

 the margin of the basin. 



Many lakes and ponds occur in the sandhills in a number of 

 scattered "lake regions." These lakes vary from small ponds a 

 hundred yards across to a mile or more wide, and from one to five 

 miles in length. Although a number of the lakes are of large size 

 they all agree in that they are relatively shallow. Aside from a 

 few deep holes the average depth of water over the rather even 

 bottom varies from three to six feet. Probably none have a depth 



