Rocky Mountains. 55 f 



country is carried off, yet, during most of the summer season, 

 it is entirely destitute of running water throughout a large 

 proportion of its extent, a circumstance in proof of the aridity 

 of the region drained by it. Fifty miles above its mouth, it 

 receives at least two-thirds of its water from its principal 

 tributary, denominated the North Fork. This fork rises be- 

 tween the Arkansa and Canadian, and has a meandering 

 course of about eight hundred miles. Six milfs above the 

 fork just mentioned, another tributary enters the Canadian, 

 catled the South Fork, about half as large as the other. Not- 

 withstanding the supplies afforded by these two tributaries, 

 the Canadian has not a sufficiency of water in summer, to 

 render it navigable evsn to their mouths. At the distance of 

 twenty miles above its mouth, a chain of rocks, (slaty sand- 

 stone) extends across the bed of che river, but occasions no 

 considerable fall. A little above the entrance of the South 

 Fork, is another of the same description, forming rapids of 

 moderate descent, not more than four hundred yards In 

 length. With these exceptions, the bed of the river presents 

 no rocky formations in place, for more than four hundred 

 miles from its confluence with the Arkansa. About three 

 hundred and fifty miles from that point, beds of Gypsum or 

 Plaster of Paris begin to make their appearance, in the bluffs 

 fronting upon the river, and upon the declivities of the high- 

 land knobs. A great abundance of this article is to be met 

 with, not only upon the Canadian, but also upon the upper 

 part of the Arkansa. The hills in which it is imbedded, are 

 composed of ferruginous clay and fine sand of a deep red 

 complexion. Hence the Arkansa derives the colouring mat- 

 ter that gives to its waters their reddish hue. 



The bottoms of the Canadian, in the neighbourhood of its 

 mouth, are possessed of a soil exceedingly prolific, but like 

 those of the other rivers of this region, the more remote their 

 situation from the mouth of the river, the more sandy and 

 sterile is their appearance. Its valley is plentifully supplied 

 with timber of an excellent quality, for a distance of about 

 two hundred miles, on the lower part of the I'iver, and the 

 highlands for nearly the same distance are agreeably diver- 

 sified with prairies and woodlands. This portion of the river 

 is situated eastward of the assumed meridian, and the coun- 

 try upon it has already been partially described in a former 

 part of this report. 



The woodland growth upon the lower part of the Cana- 

 dian, consists of cotton wood, sycamore, white, blue and 



