The West Virginia. Cyclopedia
The Allegheny Front or Appalachian Divide is imaginary line, running from Keyser in the north to Bluefield in the south, dividing the two different types of river systems that exist within West Virginia.
East of the divide, principal rivers flow parallel to each other, running between long, narrow mountain ranges, in a northeast-southwest direction, flowing toward the Atlantic Ocean.
On the west side of the divide, rivers and stream join larger streams at acute angles, and flow toward the Ohio River.