THE MIAMI SERIES OF SOILS. 7 



Another area within which the altitudes are greater than 1,000 

 feet lies along the southern portion of the Ohio-Indiana State line 

 from near Portland, Ind., to the vicinity of Liberty. This rolling 

 upland separates the drainage of the Miami Eiver from that of the 

 Whitewater Eiver, while a branch of the same ridge lies between the 

 latter stream and the eastern tributaries of the East White River. 

 These ridges do not exist as distinct topographic features, but merely 

 comprise the higher elevations in a rolling country between the 

 principal drainage basins of southwestern Ohio and southeastern 

 Indiana. With few exceptions, the local slopes and changes of ele- 

 vation are very moderate. The plain merely swells to higher inter- 

 stream ridges and sinks to the broad, terraced valleys of the present 

 streams. 



Toward the north the plain sinks in gentle undulations to the basin 

 of Lake Erie and its continuation in the broad, flat drainage system 

 of the Maumee Eiver. 



The greater part of central Indiana consists of a nearly level plain 

 having a slight inclination toward the drainage basin of the Wabash 

 Eiver on the north and west and toward the course of the White 

 Eiver in the south-central part of the State. Along the Wabash 

 this plain sinks to elevations of 700 to 800 feet. The southwestern 

 and western borders of the region occupied by the soils of the Miami 

 series do not greatly depart from the 700-foot contour line through 

 much of this region. 



North of the Wabash Eiver the region is considerably more roll- 

 ing, partly on account of the greater absolute elevation of the under- 

 lying rock formations and partly because the area is dissected by 

 numerous large streams which have cut comparatively deep channels. 



Beginning in extreme northeastern Indiana in the vicinity of 

 Kendallville, an elevated area extends to the northeast past Hills- 

 dale and Howell, Mich., to the vicinity of Lapeer. This rolling and 

 ridged section has an extreme breadth of about 50 miles and lies 

 chiefly above the 1,000-foot contour line. The elevation is due 

 mainly to the altitude of the underlying rock which is near the sur- 

 face, particularly in the vicinity of Hillsdale, and in part to the 

 depth and ridgy character of the superficial glacial deposits over 

 the more northern part of the ridge. From this ridge the land 

 slopes to the southeast and the northwest in gently undulating or 

 slightly ridged areas with intervening nearly level plains of varying 

 size. 



The only other elevations in excess of 1,000 feet in the section of 

 southern Michigan where the soils of the Miami series prevail occur 

 along the extreme northwestern border of the area. 



