[ 237 ] 18 



which takes in the sources of the Mankato and of the La Hon tan rivers, 

 subdividing itself into undulations whence proceed the waters of the Wazi- 

 ojii^ or Pine river, Miniska., or White Water river, Oka/t, or Heron river, 

 <fcc., &.C. ; all emptying into the Mississippi. 



The Mankato becomes navigable with boats within a few miles of its 

 sources. It is deep, with a moderate current along a great portion of its 

 course, but becomes very rapid on its approach to the Sr, Peter's. Its bed 

 is narrowly walled up by banks rising to an elevation of from 60 to SO feet, 

 and reaching up to the uplands through which the river flows. These 

 banks are frequently clifi^. or vertical escarpments — such as the one called 

 by the Sioux Maiiya kichaksa, or cleft elevation. The breadth of the river 

 is pretty uniformly from 80 to 120 feet wide ; and the average breadth of 

 the valley through which it flows scarcely a quarter of a mile. The latter, 

 as well as the high grounds, are well wooded ; the timber beginning to 

 spread out on both shores, especially since they have become less frequent- 

 ed by the Sioux hunters, and are not so often fired. But the crossings of 

 the river are hard to find, requiring to be pointed out by an experienced 

 guide. I have laid down on the map my route over the Undine Region, 

 and the geographical positions of the crossing places will be found in the 

 table at the end of the report. 



On the left bank of the Mankato, six miles from its moi^th, in a rocky 

 Indian blue bluff" composed of sandstone and limestone, are found cavities in- 

 earth, which the famed blue or green earth, used by the Sioux as their 

 principal pigment, is obtained. This material is nearly exhausted, and it is 

 not likely that this is the spot where a Mr. Lesueur (who is mentioned in- 

 the Narrative of Major Long's Second Expedition, as also by Mr, Feather- 

 stonhaugh) could, in his third voyage during the year 1700, have collected 

 his four thousand pounds of copper-earth sent by him to France. I have 

 reason to believe that Lesueur's location is on the river to which I have 

 affixed his name, and which empties into the Mankato three quarters of a 

 league above Fort L'Huillier, built by him, and where he spent a winter. 



This location corresponds precisely with that given by Charlevoix, whilst 

 it is totally inapplicable to the former. Here the blue earth is abundant in 

 the steep and elevated hills at the mouth of this river, which hills form a 

 broken country on the right side of the Mankato. Mr. Fremont and my- 

 self have verified this fact — he, during his visit to Lesueur river; and I^ 

 upon the locality designated by Mr. Featherstonhaugh, where the Ndako- 

 talis formerly assembled in great numbers to collect it ; but to which they 

 now seldom resort, as it is comparatively scarce — at least so 1 was in- 

 formed by Sleepy Eye, the chief of the iSissitot.s, who accompanied me 

 during this excursion. 



As 1 did in the case of the red pipostone described above. 1 will state tlie 

 mineralogical characters of the Indian blue earth, or clay. It is massive, 

 somewhat plastic, emits an argillaceous odor when breathed upon ; color, 

 bluish green ; easily scratched with the nail when formed into hardened 

 balls. The acids have no action upon it ; it is infusible before the blow- 

 pipe, but loses its color and becomes brown. This color is due to the per- 

 oxide of iron, which it contains in the proportion of ten per cent, at least. 

 It contains no potash, and but a small proportion of lime. It is a very 

 different mineral from that described by Dr. Thompson, under the name of 

 pipe clay. 



