Interstate 77 (I-77) is an Interstate Highway in the eastern United States. It traverses diverse terrain, from the mountainous state of West Virginia to the rolling farmlands of North Carolina and Ohio. It largely supplants the old U.S. Route 21 between Cleveland, Ohio, and Columbia, South Carolina, as an important north–south corridor through the middle Appalachians. The southern terminus of Interstate 77 is in Columbia at the junction with Interstate 26.