Rocky Mountains. 137 



on account of ill health, were unable to travel farther on foot, 

 should for the present remain at Isle au Vache, while the 

 other gentlemen of the detachment, should continue their jour- 

 ney. Mr. Dougherty, from his intimate acquaintance with 

 the country, was of opinion that by crossing in the nearest 

 direction from Isle au Vache to the mouth of Wolf river, they 

 might yet overtake the steam boat. They accordingly placed 

 themselves under his guidance, and by great exertion, fortu- 

 nately arrived at the mouth of Wolf river, on the evening of 

 the 1st of September, as the steam boat was passing. 



The country southwest of the Missouri, between the Kon- 

 zas and the Platte, is drained principally by Wolf river and 

 the Great Nemahaw. These rivers, like the Nodowa and 

 Nishnebottona, which enter the Missouri nearly opposite 

 them, from the northeast, rise in the prairies at an elevation 

 probably of forty or fifty feet above the level of the Missouri,, 

 As they descend, their vallies becoming gradually wider, em- 

 bosom a few trees, and at length, near their entrance into the 

 Missouri valley, are forests of considerable extent. The sur- 

 face of these prairies presents a constant succession of small 

 rounded hills, becoming larger and more abrupt, as you ap- 

 proach the beds of the rivers. The soil is deep, reposing 

 usually on horizontal beds of argillaceous sandstone, and se- 

 condary limestone. In all the limestones along the Missouri, 

 we observe a tendency to crystalline structure, and they have 

 often a reddish or yellowish white colour. There is however 

 always something in the arrangement and in the aspect of 

 the crystals, to distinguish these sparry varieties from the 

 primitive granular limestone, to which thev have something 

 of general resemblance. The horizontal disposition of the 

 strata of this limestone, the great numbers of organic relics 

 contained in it, and its intimate connexion with coal strata, 

 indicate with sufficient clearness its relation to the secondary 

 rocks. No person who shall examine this stratum with the 

 least attention either about the Nemahaw and the 'Konzas, 



vot, i. 18 



** 



