The Ohio River didn't always exist. It's a relatively "new" river, born during the Great Ice Age. Before that, two other large rivers, the Monongahela and the Allegheny, flowed in a different direction. As massive sheets of ice (glaciers) moved, they acted like a giant bulldozer, eventually blocking and diverting their paths. With their old paths blocked, their water was forced to cut a brand new channel, which we now call the Ohio River.

You can still see evidence of this powerful history. Along the banks of the Monongahela River in the Morgantown-Fairmont area, you can find thick layers of material called lake sediments. These sediments are the sand, mud, and clay that settled to the bottom of ancient temporary lakes before the water drained away.