2 lO 



THE POPULAR SCIENCE MONTHLY 



The Sand Hill Areas are indicated by the Shaded Portions on the Map. 



in quest of forage. The vegetation was closely grazed and tramped 

 into the unstable soil. And then the red man came, who killed the 

 bison for food, clothing and for many other useful purposes. He sought 

 to improve the range for the wild beast and for his own stock by burn- 

 ing the grass at certain seasons of the year. In this way a third and 

 still greater menace was forced upon the plants that were struggling so 

 hard to cover the Sand Hills with a permanent mantle of vegetation. 



The Sand Hill region of Nebraska is one of the largest and best 

 known portions of the sand hills of the Great Plains. In. our state the 

 main body of Sand Hills is oblong in shape with irregular margins. 

 This region lies north and west of the central portion of the state. 

 On the northern edge of the region there are numerous deep canyons 

 with steep, more or less wooded sides. A few more or less isolated areas 

 of Sand Hills occur outside this great main region both north and south 

 of the Platte. A glance at the accompanying map will show the loca- 

 tion and comparative size of the main region and the outlying areas of 

 sand hills. 



The Sand Hills of Nebraska cover an area of more than 18,000 

 square miles, almost one fourth of the total area of the state. This is 

 about equal to the combined areas of New Hampshire and Vermont. 

 The hills are all round-topped or conical and smooth, clearly showing 

 that they had been shaped by the wind long before their invasion by 

 plants. There are many depressions between the hills, many of which 

 assume the proportions of valleys more than a mile in width and some- 

 times many miles in length. From these well-developed valleys the 

 low places decrease in both width and length until they are mere narrow, 

 saucer-shaped basins or " pockets " a few hundred yards across. The 

 well-pronounced valleys are, as a rule, about parallel and trend in a 

 general southeast and northwest direction. Such valleys are frequently 

 completely inclosed by ranges of hills and in this way effectively sepa- 

 rated from adjacent valleys, though such may not be more than a half 



