SOURCE OF ST. PETEr's RIVER. 209 



however, as also in its productiveness, some slight differ- 

 ence may be occasioned by the natural condition of the 

 two tracts, in a geological point of view, the country east- 

 ward of the range being of a primitive, and that westward 

 of a sccondaiy character, limestone being common to both. 



II. Of the country between the Ohio river and Lake 

 Michigan. 



On tliis part of the route are presented two varieties of 

 country, distinctly marked ; the one exceedingly hilly, like 

 that between the Alleghanies and Ohio, before noticed, and 

 the other of a waving aspect, presenting extensive flats, 

 with occasional hills and swells of moderate height and de- 

 clivity. The line of division between these two tracts com- 

 mences on the Mississippi, near Cape Girardeau, and runs 

 north-eastwardly to the Miami river, thence eastwardly to 

 the Muskingum, which it crosses near Zanesville, and 

 thence north-eastwardly, passing along the sources of Big- 

 Beaver river, and terminating near the eastern extremity 

 of Lake Erie. (See Account of the Expedition from Pitts- 

 burgh to the Rocky Mountains, vol. 2, p. 333.) The re- 

 .gion situated between this line and the Ohio river exhibits, 

 as before hinted, a surface exceedingly diversified with 

 hills and vallies ; the hills uniformly present rounded sum- 

 mits; rocks are seldom abundant upon the surface, though 

 secondary lime and sandstones prevail at a moderate depth 

 below; precipices no where occur except as boundaries to 

 the numerous water-courses. The general elevation of this 

 region may be estimated at between six hundred and one 

 thousand feet above tide water, gradually increasing from 

 the mouth of the Ohio upwards. The inequalities of sur- 

 face do not render it unfit for cultivation. The vallies, es- 



