APPENDIX. 337 



sands, denote that it has been the scene of geological disturbance 

 of an extraordinary kind. 



Ulterior Conclusions. — In taking these several views of the 

 geological structure of the Northwest — of the Lake Superior 

 basin, and of the valleys of the St. Louis Kiver — the region about 

 the Upper Mississippi, its striking change at the Falls of St. An- 

 thony — and the valleys of the Wisconsin and Fox Rivers, and 

 the basins of Lakes Michigan and Huron, I am aware of the 

 temerity of ray task. Allowance must, however, be made for the 

 rapidity of my transit over regions where the question was often 

 the safety and personal subsistence of the party. A very large 

 and diversified area was passed over in a short time. At no 

 place was it possible to make elaborate observations. A thou- 

 sand inconveniences were felt, but they were felt as the pressure 

 of so many small causes impeding the execution of a great enter- 

 prise. A sketch has been made, which, it is hoped, will reveal 

 something of the phj^sical history and lineaments of the country. 

 These glimpses at wild scenes, heretofore hid from the curious 

 eye of man, have been made, at all points, with the utmost 

 avidity. I have courted every opportunity to accumulate facts, 

 and I owe much to the distinguished civilian who has led the 

 party so successfully through scenes of toil and danger, not always 

 unexpected, but alwaj'-s met in a calm, bold, and proper spirit, 

 which has served to inspire confidence in all ; to him, and to 

 each one of my associates, I owe much on the score of comity 

 and personal amenity and forbearance; and I have been made to 

 feel, in the remotest solitudes, how easy it is to execute a duty 

 when all conspire to facilitate it. 



The views herein expressed are generalized in two geological 

 maps (hereto prefixed), which, it is believed, will help to fix the 

 facts in the mind. They exhibit the facts noticed, in connection 

 with the theory established by them, and by all my observations, 

 of the construction of this part of the continent. 



The mineralogy of the regions visited is condensed in the fol- 

 lowing summary, drawn from my notes, which, it is believed, 

 constitutes an appropriate conclusion to this report. 



With the exception of one species, namely, the ores of copper, 

 the region has not proved as attractive in this department as I 

 22 



