34 THE PLAINS. 



crosses the Big Sandy, and makes a sharp bend to the 

 south, following the direction of the Big Sandy to its junc- 

 tion with the Arkansas. It then crosses the Arkansas, and 

 is joined on its south bank by another similar but smaller 

 sand-stream, which, taking its rise in the high table-land 

 between the Purgatory and Arkansas Eivers, follows the 

 general course of the latter stream. 



The Eush Creek and Big Sandy branch has a very 

 regular width of about twelve miles. The sand is disposed 

 in small hummocks, covered with broom-sage (a tall, stiff- 

 jointed grass common on the abandoned fields of Virginia 

 and North Carolina). It is loose and deep, making travel 

 extremely laborious and difficult. The Purgatory branch 

 varies from a quarter of a mile to three miles in width, 

 and is better to travel over than the other. These streams 

 when united follow the right or south bank of the Arkansas 

 in a belt of from five to thirty miles in width. Some- 

 times this belt will leave the river for a few miles ; at other 

 times the sand-bluffs stand sheer from the water to the 

 height of 200 feet. 



The sand takes every variety of form. At one place 

 the long gentle slopes, covered with grass, give at a little 

 distance no indication of the nature of the ground 

 beneath ; at another, the high bare knolls, cut in rifts by 

 the wind, look in the sunlight like huge snow-drifts. In 

 some places the ' hills,' or knolls, change their forms 

 with every wind ; in others, the wind seems to have no 

 effect whatever. The most curious fact connected with 

 these sand-streams, or ranges of knolls, is that, however 

 much they may ad do vary in form, however they may 

 be and are shifted by the ever-changing winds, all 

 variations and changes take place within the regular limits 

 or boundaries. 



The south bank of the Arkansas is bounded by 

 these hills for more than 300 miles. The wide sand- 

 bed of the river itself is in many places perfectly dry for 

 a month or more of each year. The prevailing winds 



