APPENDIX. 555 



smith's, or any other good general map of North 

 America. 



" The course of the Rocky Mountains chain," Dr. 



Richardson states*, "from the Sierra of Mexico, in 



1 latitude 30°, to its termination on the coast of the 



' Arctic Sea, in latitude 69°, is about N. by W., with 



8 very little deviation any where. The chain rises 



c abruptly from a flat or very slightly inclined country, 



( in which the great prairies of the Arkansas, Mis- 



6 souri, and Saskatchewan are included. To the 



' eastward of these prairie lands (at least N. of Lake 



{ Superior), there is an extensive limestone deposit ; 



i and between this and the primitive zone of hills or 



'rocks still farther east" — (to which may now be 



added the greater part, if not the whole, of the tract 



explored by Captain Back), " a series of rivers and 



" lakes, occupying the line of junction, and extending 



" from the Lake of the Woods to the Arctic Sea." 



" It is to be noticed, however, that although the lakes 

 " on this line almost always have primitive rocks on the 

 " east side, and limestone on the west, the connecting 

 " rivers generally run wholly in one formation or in the 

 " other. Thus, the River Winipeg flows through pri- 

 " mitive rocks ; the edge of the limestone being a short 

 way to the westward. We can trace the formation 

 up the east side of Lake Winipeg to Norway Point, 

 w and from thence straight to Beaver Lake ; the Sas- 

 " katchewan to the westward flowing over limestone, 

 " which is close to the primitive strata in Beaver Lake, 

 " The Missinippi or Churchill River f traverses pri- 

 " mitive rocks." 



* MS. letter, March 28. 1836. 



f Dr. Richardson remarks, that " The character of this 



a 



