143 Journey to the Coteau des Prairies, Sfc. 



a correct theory with regard to the time when, and the manner 

 in which, this formation was produced. That it is a secondary 

 and sedimentary deposit, seems evident ; and that it has with- 

 stood the force of the dikivial current, while the great valley of 

 the Missouri from this very wall of rocks to the Rocky Moun- 

 tains has been excavated and its debris carried to the ocean, I 

 confidently infer from the following remarkable fact. 



At the base of the wall and within a few rods of it, and on 

 the very ground where the Indians dig for the red stone, rests a 

 group of five stupendous bowlders of gneiss leaning against each 

 other, the smallest of which is twelve or fifteen feet, and the 

 largest twenty five feet in diameter, weighing, unquestionably, 

 several hundred tons. These blocks are composed chiefly of 

 feldspar and mica of an exceedingly coarse grain, (the feldspar 

 often occurring in crystals of an inch in diameter.) The surface 

 of these bowlders is in every part covered with a gray moss, 

 which gives them an extremely ancient and venerable appear- 

 ance, while their sides and angles are rounded by attrition to the 

 shape and character of most other erratic stones which are found 

 throughout the country. 



That these five immense blocks, of precisely the same char- 

 acter, and differing materially from all other specimens of bowl- 

 ders which I have seen in the great valleys of the Mississippi and 

 Missouri, should have been hurled some hundreds of miles from 

 their native bed and lodged in so singular a group on this eleva- 

 ted ridge, is truly matter of surprise for the scientific world, as 

 well as for the poor Indian, whose superstitious veneration of 

 them is such that not a spear of grass is broken or bent by his 

 feet, within three or four rods of the group ; where he stops and in 

 humble supplication, by throwing plugs of tobacco to them, soli- 

 cits their permission (as the guardian spirit of the place) to dig 

 and carry away the red stone for his pipes. The surface of these 

 bowlders I found in every part entire and unscratched by any 

 thing, and even the moss was every where unbroken, which un- 

 doubtedly remains so at this time, except where I apphed the 

 hammer to obtain some small specimens, which I brought away 

 with me,* 



* In a specimen with which we are favored by Mr. Catlin, the feldspar is in dis- 

 tinct crystals, is tinted red and greatly abounds; the quartz is gray and white, and 

 the mica black, while the moss covers nearly half the mass. — Eds. 



