SCIOTO DRAINAGE SYSTEM. 177 



however, it crosses a rock point in the old south bluff, as indicated by 

 Orton/ The old drainage system, of which this valley is the lower course, 

 probably drained aii area of several hundred square miles, but as yet only 

 a few of the old tributary lines have been traced. 



It was noted several years ago by H. W. Overman, county surveyor 

 of Pike Countj^, that the headwater portion of Brush Creek above Fort 

 Hill formerly discharged to the preglacial valley of Paint Creek at Bain- 

 bridge." This interpretation was independt ntly reached by the writer in 

 1889, and by Tight and Fowke a few years later.^ There is a well-defined 

 though partially filled valley connecting it at the north with Paint Creek, 

 while at the south, near Fort Hill, the present stream is cutting a gorge across 

 a low pass in the old divide. 



' The region now drained by Rocky Fork, a branch of Paint Creek, 

 appears to have been drained by a line farther north, whose valley is only 

 partially filled. A few suggestions of the old courses of drainage were 

 obtained in northern Highland County and in Fayette County, but they 

 are scarcely complete enough to justify a mapping or full interpretation of 

 the lines of discharge. 



THE LOWER COURSE. 



The Scioto Basin terminates on the south at the hills of Ross County, 

 just above Chillicothe. The Scioto there enters a district in which the hills 

 rise 400 to 500 feet above the stream, and flows in a valley but little more 

 than a mile in average width. The evidence that this lower course of the 

 Scioto has now a discharge in the reverse direction from that of the old 

 system has been so fully presented in connection with the discussion of the 

 Ohio that only this passing reference seems necessary. 



WESTERN TRIBUTARIES SOUTH OF THE GLACIAL BOUNDARY. 



South of the glacial boundary the western tributaries of the Scioto are 

 all small, and all are following their old lines. The most important one 

 is Scioto-Brush Creek which drains the northwestern part of Scioto County 

 and the eastern border of Adams County. Sunfish Creek di-ains nuich of 

 the western half of Pike County, while Camp Creek and Bear Creek drain 



1 Geology of Ohio, Vol. II, 1874, pp. 653-655. 



2 Ohio Archfeological and Historical Quarterly, Vol. I, 1887-1888, pp. 260-264. 

 »Bull. Denison Univ., Vol. IX, Pt. I, 1895, pp. 15-34. 



MON XLI 12 



