VALLEY OF THE MISSISSIPPI, 31 



more than the neighbouring beds of red clay, which 

 occasionally inundated, and cashed- by the winter 

 rains, afterwards deposit a copious efflorescence of 

 ilie dissolved mineral. 



From three experienced hunters who had spent a 

 great part of their lives in tiiis country, and pene- 

 trated to the western mountains, I received accounts 

 of the prevalence of a mineral towards the sources of 

 Red river, which, on producing specimens, turned 

 out to be fibrous gypsum, similar to that of the 

 Utawah river, in Upper Canada ; it was said to be 

 very abundant and continuous in its appearance. My 

 guide, Mr. Lee, first observed it on the banks of what 

 the French call the False Washita, one of the prin- 

 cipal northern branches of lied river. A river of 

 saline water too brackish to drink, as I was informed, 

 enters the river Platte from the south, about thirty 

 miles above its confluence with the Missouri. The 

 Sioux river entering the Missouri from the north, 

 according to the report of the interpreter (Borion) 

 who accompanied us in our voyage up the Missouri, 

 in IS 10, informed us, that this river sources with the 

 St. Peters, and after remaining navigable for upwards 

 of two hundred miles, is then obstructed by a cataract, 

 and that below the falls a creek enters from the 

 eastward, after passing the cliffs of the red clay-stone 

 employed by the Indians in the fabrication of their 

 pipes. 



From what we can glean concerning this principal 

 formation of salt and gypsum, it would appear to be 

 situated in the vicinity of the primitive mountains, 



