70 EXPLORATION OF THE COUNTRY BETWEEN 
Brulés”’ by the Canadian voyageurs. These hills are 
covered with fragments of selenitic crystals, or gypsum, which glisten 
s rays like gems, and from this fact are sometimes called 
the ‘‘ Shining Hills.’’ Above the mouth of the Cannon Ball river, 
the sands and elays of the Tertiary system commence, and the general 
a of the country is much improved; the upland is covered 
with a fine « 
About fifty miles be e 
favorite wooding place for steamboats in their ascent of the river. 
This island is one of three which are destined to be of much interest 
to the settlers along the Missouri. They have an area of several 
the largest trees are not more than two feet in diameter. e 
quantity of fine timber might be selected from these islands with ai 
vantage to the remainder. They are also the resort of myriads of 
birds and larger animals, which gather to these places to rear their 
young undisturbed. — 
e country in the vicinity of Fort Pierre, and north towards the 
Black Hills, though mostly sterile or entirely barren, contains some 
plateaus that are covered with a fine growth of grass. The region 
fr ren black hills, sometimes producing a few 
stunted cedars, meet the eye on every side. Between the two forks of 
the Shyenne, and in the vicinity of Bear Butte, a portion Black 
_ Hills, is quitea large area, which seems to have bee 
