‘At the falls of St. Anthony, the river has a perpendicular pitch of forty feet, and from this to its junction with the Missouri, a distance of eight hundred and forty-three miles, it is bounded by limestone bluffs, which attain various elevations from one to four hundred feet, and present a succession of the most sublime and picturesque views. This forms the third characteristic change of the Mississippi. The river prairies cease, and the rocky bluffs commence precisely at the falls of St. Anthony. Nine miles below it receives the St. Peter’s from the west, and is successively swelled on that side by the Ocano, Iowa, Turkey, Desmoines, and Salt rivers, and on the east by the St. Croix, Chippeway, Black, Ouisconsin, Rock, and Illinois. One hundred miles below the falls of St. Anthony, the river expands into a lake, called Pepin, which is twenty-four miles long and four in width. It is, on issuing from this lake, that the river first exhibits, in a striking manner, those extensive and moving sandbars, innumerable islands and channels, and drifts and snags, which continue to characterize it to the ocean. Its bends from this point onward are larger, and its course more direct; and although its waters are adulterated by several dark colored and turbid streams, it may still be considered transparent. The principal impediments to navigation in this distance are the Desmoines, and Rock river rapids. The latter extends six miles, and opposes an effectual barrier to steam-boat navigation, although keel-boats and barges of the largest classes, may ascend. This rapid is three hundred and ninety miles above St. Louis. ‘The fourth change in the physical aspect of this river is at the junction of the Missouri, and this is a total and complete one, the character of the Mississippi being entirely lost in that of the Missouri. The latter is, in fact, much the larger stream of the two, and carries its characteristic appearances to the ocean. It should also have carried the name, but its exploration took place too long after the course of the Mississippi had been perpetuated in the written geography of the country, to render an alteration in this respect, either practicable or expedient. The waters of the Mississippi at its confluence with the Missouri, are moderately clear, and of a greenish hue. The Missouri is turbid and opake, of a grayish white color, and during its floods, which happen twice a year, communicates, almost instantaneously, to the combined stream its predominating qualities, but towards the close of the summer season, when it is at its lowest stage of water, the streams do not fully incorporate for twenty or thirty miles, but preserve opposite sides of the river; and I have observed this phenomenon at the town of Herculaneum, forty-eight miles below the junction.