Geography of Ohio 397 



illustrated in drainage studies in the Appalachian areas, by Pro- 

 fessor Davis.' 



The remote sources of the Great Miami are in Hardin county. 

 Since so many rivers rise in this county, it would appear that 

 the region must have a relatively high altitude; the caus(\, however, 

 is rather the glacial deposits which have converted much of the 

 area into a great swamp. This swamp, in effect, is a broad 

 divide. Numerous streams usually flow away from an extensive 

 marsh area. From Dayton northward, the Great Miami has 

 many branches. At Dayton it receives the Stillwater creek, and 

 Mad river. Each of these tributaries is quite comjilex; the 

 former drains nearly all of Darke county; the latter, S])i'ingfield 

 and (champaign counties and parts of Logan. The remainder 

 of Logan county gives its drainage to the Miami proper. Much 

 of the surface water of Shelby county is gathered into Loi-amie 

 reservoir, which overflows into the Miami. From Dayton south- 

 ward, this river follows a mature valley, and only its tributaries 

 at some distance from the flood i)hiin show any evidence of youth. 

 The Miami has no very long branches between Dayton and the 

 Ohio river; on the west are several small creeks, some of them ris- 

 ing in Indiana. The junction of the Great Miami and the Ohio 

 is formed just across the state line in Indiana. 



Little Miami. This stream, al)out 100 miles long, has its 

 source in Clarke county. Its basin, involving about 1850 sc^uare 

 miles, includes parts of Greene, Clinton, Highland, Brown, War- 

 ren, Clermont and Hamilton counties. This river is parallel 

 to the Great Miami; and its nearness to the larger stream accounts 

 for its receiving from the west no branches of any consequence ; on 

 the east it has tributaries that rise many miles away. 



Scioto river. The drainage basin of this stream is asymmetric: 

 it receives few and short tributaries from the east, while the west- 

 ern side of its basin gives many long branches. The remotest 

 headwater sources of the Scioto rise in Morrow, Crawford and Au- 

 glaize counties; its length is 210 miles, and it drains an area of 6400 

 square miles. An interesting feature of this stream is the numer- 

 ous quite parallel branches that cross Delaware and Franklin 

 counties. Of these the Big Walnut, Allen creek, and Olentangy 

 are found within an east-west distance of ten miles; they are slightly 



3 Loc. cil., pp. 434-441. 



