HISTORICAL SKETCH 31 



1820, Cass.] 



The channel on the right side of the island is about three times the width of that on the left. 

 The quantity of water passing through these is not, however, in the same proportion, as about 

 one-third part of the whole passes through the left channel. In the broadest channel, just below 

 the cataract, is a small island also, about fifty yards in length, and thirty in breadth. Both of 

 these islands contain the same kind of rocky formation as the banks of the river, and are nearly 

 as high. Besides these, there are immediately at the foot of the cataract, two islands of very 

 inconsiderable size, situated in the right channel also. The rapids commence several hundred 

 yards above the cataract, and continue about eight miles below. The fall of the water, beginning 

 at the head of the rapids, and extending two hundred and sixty rods down the river to where the 

 portage road commences, below the cataract, is, according to Pike, fifty-eight feet. If this esti- 

 mate be correct the whole fall from the head to the foot of the rapids is not probably much less 

 than one hundred feet. But as I had no instrument sufficiently accurate to level, where the view 

 must necessarily be pretty extensive, I took no pains to ascertain the extent of the fall. The 

 mode I adopted to ascertain the height of the cataract was to suspend a line and plummet from 

 the table rock on the south side of the river which at the same time had very little water passing 

 over it, as the river was unusually low. The rocky formations at this place were arranged in the 

 following order from the surface downward : A coarse kind of limestone in thin strata contain- 

 ing considerable silex ; a kind of soft friable stone of a greenish color and slaty fracture, probably 

 containing lime, alumina and silex ; a very beautiful stratification of shell limestone, in thin plates, 

 extremely regular in its formation and containing a vast number of shells, all apparently of the 

 same kind. This formation constitutes the table rock of the cataract. The next in order is a 

 white or yellowish sandstone so easily crumbled that it deserves the name of sand-bank rather 

 than that of a rock. It is of various depths, from ten to fifty or seventy-five feet, and is of the 

 same character with that found at the caves before mentioned. The next in order is a soft, friable 

 sandstone, of a greenish color, similar to that resting upon the shell limestone.* These stratifica- 

 tions occupy the whole space from the low-water mark nearly to the top of the bluffs. On the 

 east, or rather north side of the river, at the falls are high grounds at the distance of half a mile 

 from the river, considerably more elevated than the bluffs, and of a hilly aspect. 



GOVERNOR LEWIS CASS' EXPEDITION TO THE UPPER MISSISSIPPI. 



In 1820 Gov. Lewis Cass, of Detroit, conducted an exploring expedition 

 from Detroit to the upper Mississippi region, coasting the shores of lakes 

 Huron and Superior in canoes. From the head of lake Superior he fol- 

 lowed the route, then much traveled, for canoes, by portaging, to Sandy 

 lake and the upper Red Cedar lake, the latter of which was denominated 

 Cass lake, by Mr. H. R. Schoolcraft, the chief narrator of the expedition.! 

 This lake was considered by him, as by Lieut. Pike, the chief head of 

 navigation of the Mississippi. 



In passing the falls of Pokegama, Mr. Schoolcraft made the observation, 

 that " the Mississippi at this point forces its way through a quartzy rock, 

 during which it sinks its level, as estimated, twenty feet, in a distance of 

 about three hundred yards. There is no perceptible cascade, or abrupt fall. 



Major Long here seems to have made an error similar to that of Keating at Fort Snelling, taking fallen fragments 

 to be in situ, 



fSummary narrative of an exploratory expedition to the sources of the Mississippi in 1820, resumed and com- 

 pleted by the discovery of its origin in Itasca lake in 1832, with appendixes. By Henry E. Schoolcraft. 



