144 Feather stonhaugWs Geological Report. 



was very well acquainted with the whole country between 

 the St. Peter's and the Missouri, and had often crossed the 

 Coteau de Prairie, but he had never heard of or seen any- 

 thing like copper. This, however, was not particularly dis- 

 couraging, as Le Sueur^s mineral was described as being a 

 green and blue earth ; and it might very well be an oxyde or 

 carbonate in the carboniferous limestone, as it is found in the 

 Wisconsin Territory. I therefore entered the Makato with 

 some confidence. Its waters were extremely discolored, and 

 I immediately saw they were the cause of the turbid state of 

 those of the St. Peter's. When we had proceeded about a 

 mile, we found a family of Nacotahs, of the Sissiton tribe, en- 

 camped on a sand-bar, taking care of some venison they had 

 just killed. The locality I was in search of was well known 

 to them, and they gave us very intelligible directions. The 

 current was exceedingly strong, running about two miles an 

 hour, and the stream appeared to furnish about one-half the 

 volume of the St. Peter's. About three miles from the en- 

 trance of the river there is a singular conical hill covered with 

 grass on the right bank, which I thought a very probable sit- 

 uation for M. Le Sueur's Fort L'Huillier, and I should have 

 landed to examine it but for my anxiety to reach the blue- 

 earth locality, and on account of the weather, the snow falling 

 as we passed it, (September 22.). Near six miles from the 

 mouth, a fork of the river came in from the left bank, about 

 forty-five yards wide, on the right bank of which is a ridge of 

 from eighty to one hundred feet w r ide, very well wooded, and 

 fronting a prairie on the opposite side. We found very little 

 current, the main stream having forced it back for some dis- 

 tance. About two miles up this fork, we at length came to a 

 bluff', about one hundred and fifty feet high, on the left bank, 

 containing the blue-earth locality. On climbing it, I found 

 the same horizontal sandstone and siliceous sandstone common 

 to the whole country. Towards the top was a broad seam of 

 bluish clay, intermixed in places with silicate of iron, being a 



