BEAVER CANALS, MEADOWS, AND TRAILS. 213 



stone of a reddish-brown color, the nature of w4iich I 

 was not able to ascertain, which assumes not less re- 

 markable forms. It CTops out in the form of narrow, 

 long, and low stone walls, with horizontal lines of strat- 

 ification or seams distinctly visible; and vertical rents 

 here and there, from top to bottom, which give to it 

 the appearance of dry stone walls. In some places, 

 gateways through them, formed with the most perfect 

 regularity, are seen. These brown-stone walls run 

 parallel with the river in some places, and in others 

 diagonally up its banks.^ 



In Arabia Petrgea there is a white wall formation 

 very similar to the one here imperfectly described. In 

 future years, when the Upper Missouri region becomes 

 more accessible, a summer expedition to the "white 

 walls" will abundantly reward the tourist. 



This river is also celebrated for its game. All of the 

 principal animals of the North American Continent 

 are found upon its banks. The buffalo, elk, red and 

 black-tailed deer, antelope, grizzly and black bear. 



^ Lieutenant Grover, after first referring to the "white walls," 

 speaks of this brown rock as volcanic. " The bluffs," he remarks, 

 "are now more abrupt, and crowded the river; colonnades and 

 odd detached pillars of partially cemented sand, capped with huge 

 globes of light brownish sandstone, tower up from their steep 

 sides to the height of a hundred feet or more above the water. 

 Then the action of the weather upon the bluffs in the background 

 has worn them into a thousand grotesque forms, while lower down 

 their faces seams of volcanic rock from three to six feet thick, 

 with a dip nearly vertical, and no uniform strike, beaten and 

 cracked by the weather, rising from six to eight feet above the 

 surface, run up and down the steep faces and projecting shoulders 

 of the clifi"-^a most perfect imitation of dry stone walls." — 

 Physics and Hydraulics of the Mississippi River, p. 58. 



