Rocky Mountains. 163 



8th. The quantity of water in the river, had now become 

 so considerable, as to impede our descent along the bed, but 

 the valley was narrow and so filled with close and entangled 

 forests, and the uplands so broken and rugged, that no other 

 path appeared to remain for us. We therefore concinued to 

 make our way, though with great difficulty, and found our 

 horses much incommoded, by being kept almost constantly 

 in the water, as we were compelled to do, to cross from the 

 point of a sand bar on one side the river, to the next on the 

 Other. Quicksands also occurred, and in places where we 

 least expected it, our horses and ourselves were made to bite 

 the dust^ without a moment's notice. These sudden falls, oc- 

 casioned b\- sinking in the sand, and the subsequent exer- 

 tions necessary to extricate themselves, proved extremely 

 harrassing to our jaded horses, and we had reason to fear, 

 that they would fail us, in our utmost need. 



Above the falls the width of the river, that is, of the space 

 included between its two banks, varies from three hundred 

 yards, to two miles; below, it is uniformly narrower, scarce 

 exceeding four hundred yards. The beaches are sloping, and 

 often covered with young cotton-wood or willow trees. In 

 the Missouri, Mississippi, and to some extent in the Arkan- 

 sa, and its tributaries, the islands, sand-bars, and even the 

 banks are constantly shifting place. In the progress of these 

 changes, the young willows and cotton-wood trees, which 

 spring up wherever a naked beach is exposed, may be sup- 

 posed to have some agency, by confining the soil with their 

 roots, and arresting the dirt and rubbish in times of high 

 water. In the Missouri, the first growth which springs up in 

 these places, is so commonly the willow, that the expressions 

 "willow bar," and "willow island," have passed into the 

 language of the boatmen, and communicate the definite idea 

 of a bar or an island, recently risen from the water. These 

 willows become intermixed with the cotton-wood, and these 

 threes are often almost the exclusive occupants of extensive 



