NATURAL AREAS AND REGIONS 



355 



and covered with a mantle of drift. 

 Level areas and gentle slopes are the 

 rule. In the eastern part of the state, 

 the sandstones and conglomerates of the 

 Mississippian and Pennsylvanian series 

 have resisted erosion and given rise to 

 a more rugged topography. Several 

 physiographic boundary lines cross the 

 state. The most prominent of these 

 is the one separating the "hill country" 

 from the plains to the west. 



The "hill country" is a part of the 

 Allegheny Plateau. It includes a glaci- 

 ated northern part and an unglaciated 

 southern part. Adjoining the hill 

 country, in Adams and Brown counties, 

 is a small area belonging to the Interior 

 Low Plateau. The topography is less 

 bold than that of the Allegheny Plateau 

 to the east, but more hilly than that 

 to the northwest. 



The remainder of the state belongs to 

 the Central Lowland Province. This is 

 divided into the Lake Section and the 

 Till Plains. The boundary between 

 these two is approximately the shore- 

 line of glacial Lake Naumee, and sepa- 

 rates the level lake plains from the roll- 

 ing till plains. 



The Lake Section extends along the 

 shore of Lake Erie as a narrow belt 

 varying in width from about 10 mi. in 

 the east to 20 at Sandusky and 50 at the 

 western boundary of the state. Part of 

 it is a succession of lake beaches, with 

 sandy soil; the large area in the west 

 the old lake bed is very flat and poorly 

 drained. 



The Till Plains occupy all of western 

 Ohio except the northern part. The 

 area occupied by the Wisconsin drift is 

 level to rolling; it is crossed by a series 

 of terminal moraines. The topography 

 of the Illinoian drift area, except near 

 the largest streams, is peculiar. The 

 land is level and poorly drained; the 

 streams have cut narrow though some- 

 times deep valleys, but have left exten- 

 sive undissected areas of drift. 



SOILS 



Twenty-six soil types are recognized 

 in Ohio, and classified as residual, 



glacial, loess, terrace, and alluvial soils. 

 Soils of the Allegheny Plateau, whether 

 glacial or residual, are usually sandy; 

 those of the Till Plains, calcareous, 

 though poor surface drainage has in 

 many places resulted in an acid surface 

 and calcareous subsoil. The Interior 

 Low Plateau has a residual limestone 

 soil. The soils of much of the Lake 

 Section are characteristically black 

 (Clyde Series), and this color, together 

 with the poor drainage, has given rise to 

 the name "Great Black Swamp." Arti- 

 ficial drainage has converted the Great 

 Black Swamp of pioneer days into fertile 

 farm land. 



PLANT LIFE 



The whole of Ohio lies in the Decidu- 

 ous Forest Area except a very small 

 part in northeastern Ohio, correlated 

 with a higher annual precipitation (40 

 in.) and the shortest growing season 

 in the state (134 days). Except for the 

 few small prairie areas of the western 

 part, the whole state was originally 

 covered with one of the finest hardwood 

 forests of the country. Accounts of 

 pioneer days and early travels (Stage 

 Coach Journey across Ohio in 1834) 

 give us a fair idea of the grandeur and 

 magnitude of this forest. Most of the 

 deciduous trees and many of the conifers 

 of eastern United States occur within 

 its limits. Over 2000 species of vascular 

 plants have been recorded from Ohio. 

 In the western half of the state, only 

 a small part of the forest remains 

 isolated areas, pasture woodlots from 

 which to reconstruct the picture. Ohio 

 is primarily an agricultural state, 

 and this level and rolling land is pre- 

 eminently suited to agriculture. The 

 forests of the hill country have more 

 largely escaped the ax, and while few 

 absolutely virgin areas remain, much 

 of the land is forested and will probably 

 remain so. 



The early surveyors noted the trees 

 at section corners, and from these 

 records, Dr. Paul B. Sears has recon- 

 structed a map showing the virgin forest 



