The, supposedly, oldest river in North America is the New River which flows for 250 miles from North Carolina through Virginia and into West Virginia where there is a name change, roughly when it turms west, to the Kanawha River. The Kanawha then flows an additional 97 miles long before emptying into the Ohio River at Point Pleasant, WV. It also is unique in that it carves its way through the Appalachian Mountains contrary to the normal way the ridges of these very old mountains run, roughly southwest to northeast.
Near Charleston, WV, the Kanawha river departs from the path of the ancient Teays River which flowed almost due west to where Huntington, WV now sits. The Teays River system originated long before 2 million years ago, in the Tertiary Period, and had its headwaters in western North Carolina near Blowing Rock. It flowed northward across Virginia and West Virginia, where its course is marked by the valleys of the modern New River (a misnomer, as it is actually very old) and the Kanawha River. From St. Albans, West Virginia, the Teays flowed westward to Wheelersburg, Scioto County, Ohio, and then northward to Chillicothe, Ross County. This valley segment is dramatically visible on satellite imagery.