1875.] 211 [Hoffman. 



and gravel, and the changing of its course from the western to the 

 eastern side of the valley is difficult of determination. During the 

 season of floods, ice gorges have been formed in the main channel, 

 which caused the water to take a new course, which in a short period 

 became the navigable current, thus leaving an island as it were, be- 

 tween the old and new courses, as appears to have been the case 

 at Grand River. Mounds and other primitive earthworks occur from 

 Bonhomme Island to the mouth of the Yellowstone, and up that river 

 for a distance of over three hundred miles. There are no mounds or 

 ancient earthworks in the immediate vicinity of the settlement, 

 except the one at Grand River, which has been described by Mr. A. 

 Barrandt, in the Smithsonian Report for 1870, p. 406. 



MODERN REMAINS. 



Modern remains exist showing that the bluffs and prairie were 

 once the home of a powerful tribe. Many of the Sioux are still liv- 

 ing, who, with their tribe, in moving up the Missouri River reached 

 that point where the military station is now located, and found a 

 tribe with whom they engaged in battle. After an engagement lasting 

 four days, the Sioux were victorious and drove the conquered people 

 up the river as far as the present sites of Forts Berthold and Ste- 

 venson. This occurred in the year 1818. 



All that remains of the Ree villages, — for this was the tribe,^ — are 

 immense numbers of low mounds, scattered, or in groups, and extend- 

 ing along the bluffs over an area of several miles either way. The 

 most southern point occupied, was the spur formed by the union of 

 Oak Creek and the Missouri River. This group covers an area of 

 nearly an acre, and is surrounded by a ditch, which was originally six 

 feet wide, and two or three feet deep. Portions of the ditch have 

 become indistinct by filling up with the drift material from the sur- 

 rounding prairie. The mounds are usually from three to six feet 

 in diameter, and sometimes reach from twelve to fifteen feet in height, 

 although the majority of them are nearly leveled and would be over- 

 looked by a casual observer. 



They are composed of hard mud — no doubt at one time adobe, 

 sand, fragments of quartzite, jasper, agate and chalcedony, pieces of 

 broken pottery, but more especially of bones, amongst which I found 

 those of the buffalo in excess ; also elk, antelope, bear, and smaller 

 bones, especially those of the Rodents and aquatic birds, with scales of 



