SCIOTO DKAINAGE SYSTEM. 175 



system presents very few lines which are identical in extent and direction 

 of drainage with the old system; indeed a large part is quite independent 

 of the old system. 



THE HEADWATER PORTION. 



In the northern portion of the present system from the source down to 

 the glacial boundary near Chillicothe the extent and the direction of dis- 

 charge for the main stream and its tributaries are determined chiefly by 

 the slope of the great Scioto Basin, the drift filling being so great as to 

 nearly conceal the lines of preglacial drainage. This basin slopes from the 

 eastern and western borders toward a north-to-south axis, while the axis 

 itself has a decided southward slope. Moraines govern the courses of 

 drainag'e only to a limited extent. 



The Scioto itself leads down from the western rim to the axis of the 

 basin in an eastward course, wliich is governed by a moraine lying on the 

 north side of the river. It is met near Marion by a small northeastern 

 tributary, Little Scioto River,' whose course is along the south border of the 

 eastward continuation of the same moraine. The united stream then takes 

 a southward course, but flows a little to the west of the axis of the basin as 

 far as Columbus. In this portion the axis of the basin is more nearly fol- 

 lowed by the Olentangy River, which for a distance of about 40 miles lies 

 only 4 to 8 miles east of the Scioto. The two rivers become united at 

 Columbus, where the Scioto makes an eastward turn to receive the Olentangy. 

 From Columbus to Chillicothe the Scioto follows nearly the axis of the 

 basin. 



The Scioto receives three western tributaries above Columbus — Rush 

 Creek, Bokes Creek, and Mill Creek. Each of these, like the main stream, 

 rises on the elevated western rim of the basin. The courses of these 

 tributaries are governed to some extent by morainic ridges, there being a 

 ridge between Mill Creek and Bokes Creek, and another along a part of 

 the north border of Rush Creek. Below Columbus three large western 

 tributaries — Darby Creek, Deer Creek, and Paint Creek — are received. 

 Darby Creek flows eastward from the western rim of the Scioto Basin along 

 the south border of a morainic ridge to within a few miles of the Scioto. 

 It there turns southward and joins the Scioto near Circleville. Its chief 



'This stream must be distinguished from a tributary of the Ohio of the same name whicli, as 

 above described, enters the Ohio a few miles east of the mouth of the Scioto. 



