Rocky Mountains. ST 



nerally prevails, it is probable that the place will be unheal- 

 thy, till extensive clearings are made in its vicinity. 



This position may be considered as the head of constant 

 navigation for the Mississippi. The Mississippi from New 

 Orleans to the Ohio, is navigable for boats of the largest 

 size, and America may be considered as the head of con- 

 stant as well as heavy navigation. Ice is seldom to be found 

 in the Mississippi, as low down as the mouth of the Ohio 

 and never in so large quantities as to oppose any serious ob- 

 struction to the navigation. 



The navigation of the Ohio has a serious impediment 

 about four and a half miles above the town, occasioned by 

 a limestone bar, extending across the river, called the Grand 

 Chain, This bar is impassable in the lowest stage of the 

 water, and will not admit boats of any considerable burden, 

 except in the higher stages. 



The Mississippi has, in like manner, two bars, called the 

 Big and Little Chain, which appear to be a continuation of 

 the same range of rocks as that in the Ohio, extending 

 across the point of land, situated between the two rivers. 

 These bars are situated a little above the Tyawapatia Bottom, 

 about thirty miles above the mouth of the Ohio, and in low 

 water have but a moderate depth of water across them, 

 which, added to the rapidity of the current, occasions a 

 serious obstacle to the navigation. 



Boats suited to the navigation of both rivers above the 

 bars here specified, should be of inferior size ; those for 

 the Mississippi, not exceeding one hundred tons burden, and 

 those for the Ohio, from fifty to seventy-five tons. 



Any position on the Mississippi in the neighbourhood of 

 the Ohio, would be objectionable for the following reasons : 

 First, The rapidity of the current, which renders it 

 difficult to find a safe and commodious landing, there be- 

 ing no rocky-bound shore within thirty miles above and a 



