UPPER OHIO DRAINAGE SYSTEM. 93 



From au examination of these gradation plains it appears probable that 

 the divide between the old systems was somewhere south of Bellaire at the 

 time the present Ohio was formed. Whether it was between Bellaire and 

 ]\Ioundsville or at the curves of the Ohio below Moundsville may not be 

 easy to determine. There are features which suggest that it may have 

 been within 2 miles south of Bellaire, at the place where the high ridge 

 south of McMahons Creek comes to the river bluff from the west. A 

 similar high ridge sets in on the east bluff, separating Boggs Run, a north- 

 flowing stream, from Cemetery Run, a south-flowing stream, and leads 

 thence eastward to form the local divide between Wheeling and Grave 

 creeks. Within 2 or 3 miles of the river this ridge attains an altitude 

 of 1,360 to 1,400 feet, and is nearly 1,200 feet at the river bhiffs. In 

 addition to its pi'ominence, there is also a difference in drainage features 

 on opposite sides of the ridge, which may favor the view that it constituted 

 an old divide, though not necessarily a very long-continued one. South 

 of the ridge the uplands generally show a greater dissection than to the 

 north, such as would result from connection with the system of drainage 

 to the south, which, as shown by the gradation 23lains of Fish and Fishing 

 creeks, is more than 100 feet below that of the gradation plains immedi- 

 ately north of this ridge. There is, however, south of this ridge the 

 gradation plain on Grave Creek, which stands so high as to suggest that it 

 once belonged to the north-flowing system. There is also the fact that the 

 Ohio Valley is exceptionally large just below this ridge, as if the strata 

 there were very weak in their resistance to erosion. In the present state 

 of knowledge, therefore, it can scarcely be decided whether the divide at 

 the time the Ohio was established was at the ridge above Moundsville or 

 at the curves in the Ohio below that city. Possibly it stood for a time at 

 the curves below Moundsville, and was shifted by stream piracy to the 

 ridge above that city. Indeed, as jjreviously indicated, the divide may 

 have migrated northward, through stream piracy, from the elevated country 

 near New Martinsville to the points in question. An inspection of the map 

 will show that Moundsville seems to be in the midst of an old drainage 

 system, rather than at an old divide. To place a divide there certainly 

 gives to the section between Moundsville and New Martinsville the appear- 

 rance of a truncated drainage system, but to place the divide near New 

 Martinsville, either above or below Fishing Creek, gives a natural appear- 



