58 NARRATIVE, &c. 



the island. Other parts of the lake yield small species of the 

 unio, which were found strewing the bed of the outlet. And 

 it may here be remarked, that this shell exists, in the largest 

 and heaviest species heretofore known, in the lower parts of 

 this stream — the Mississippi having its origin here. 



The outlet of Itasca Lake, is perhaps ten to twelve feet 

 broad, with an apparent depth of twelve to eighteen inches. 

 The discharge of water appears to be copious, compared to its 

 inlet. Springs may, however, produce accessions which are not 

 visible, and this is probable both from the geological character 

 of the country, and the transparency and coolness of the water. 



The height of this lake, above the sea, is an object of geo- 

 graphical interest, which, in the absence of actual survey, it 

 may subserve the purposes of useful inquiry, to estimate. From 

 notes taken on the ascent, it cannot be short of one hundred 

 and sixty feet above Cass Lake. Adding the estimate of 1330 

 feet, submitted in 1820, as the elevation of that lake, the Missis- 

 sippi may be considered to originate at an altitude of 1490, say 

 1500 feet, above the Atlantic. Its length, assuming former data 

 as the basis, and computing it, through the Itascan, or west 

 fork, may be placed at 3160 miles, one hundred and eighty-two 

 of which, comprises an estimate of its length above Cass Lake. 

 Its general course, in ascending, above the latter point, is north of 

 west, as far as Lac Travers. Then south to its primary forks which 

 is continued, following up the east fork to Kubbakunna Lake, and 

 for some distance further. It then varies a short distance, north 

 and northwest, then southwest and south, and finally southwest, 

 to its main source in Ossowa Lake. The portage thence to Itasca 

 Lake, is west southwest. Both these lakes appear to rise in 

 springs, on the height of land. They are separated by about six 

 miles of country. Their latitude, we had no means of accurately 

 determining. From daily notes of the courses and distances, kept 

 by Lieut. J. Allen, as indicated by a compass and watch, their 

 position is, however, shown to be southwest, and not, as hereto- 

 fore supposed, northwest, of Cass Lake. They are, in fact, a 



