FeatherstonhaugVs Geological Report. 95 



RECONNOISSANCE FROM WASHINGTON TO THE 

 COTEAU DE PRAIRIE. 



Trusting that the explanation of geological principles which 

 I have given in the preceding pages will enable uninitiated 

 readers to comprehend more easily the unavoidable techni- 

 calities of geological descriptions, I proceed now to a relation 

 of my reconnoissance, during the past season, from the seat of 

 Government to the Coteau de Prairie, a ridge of high prairie 

 land lying between the Missouri and the Minnay Sotor Wata- 

 pah (as it is called in the Nacotah or Sioux language) or the 

 St. Peter's river. Desirous of making the opportunities for 

 observation which would occur on rny route to Green Bay as 

 interesting and useful to the country as circumstances would 

 permit me to do, I determined to follow the valley of the Poto- 

 mac into the great Western bituminous coal field. To this I 

 was induced by various considerations. This route would 

 lead me along the line of the Chesapeake and Ohio canal, a 

 work which deserves to be considered of great magnitude, as 

 well in relation to the extraordinary difficulties which have 

 opposed themselves to its construction, the amount of capital 

 involved in it, in which the Government is so deeply interested, 

 and the real state of the resources of the country through 

 which it passes, upon which a dependance is placed for the 

 eventual indemnification of its cost. The inspection of this 

 valley could not but be favorable to a correct apprehension of 

 the geological structure of the country from the falls of the 

 Potomac towards its sources : the natural sections on the river 

 were numerous, and the works on the canal had laid open 

 many others, so lhat any one who had before traversed this 

 region by land, with sufficient leisure to note the most inter- 

 esting features of the mineral formations, could not but receive 

 an instructive lesson on a line where the formations are so 

 repeatedly laid open as they are on the banks of this rirer. 



