During most of the Cenozoic Era, the Teays River and its tributaries drained a large area of the eastern U.S. Heading in the mountains of northwest North Carolina and southwest Virginia, this large river flowed northward through West Virginia, northwestward across Ohio and then westward across northern Indiana and Illinois before merging with the Upper Mississippi. As the Nebraskan and Kansan Glaciers plowed into the Midwest (2 million to 600,000 years ago), the channel of the Teays was blocked with ice and a large lake, comparable to Lake Erie in size, covered southern Ohio, northwestern West Virginia and northern Kentucky. Eventually, these lake waters spilled to the west-southwest, creating the Ohio River channel.
The New and Kanawha Rivers of West Virginia are remnants of the Teays, as is the Scioto Valley of southern Ohio; the Scioto River now flows southward through the old Teays valley. The upper Ohio River, east of the Kanawha junction, was formerly a tributary of the Teays. All remnants of the Teays Valley across western Ohio, northern Indiana and Illinois have since been buried by a thick layer of glacial till.
