What does Roanoke gap and harpers ferry have to do with Blue ridge?

Roanoke Gap and Harpers Ferry are both located along the Blue Ridge Mountains, which is a prominent mountain range in the eastern United States. Roanoke Gap is a natural passageway through the Blue Ridge Mountains in Virginia, while Harpers Ferry is a town located at the confluence of the Potomac and Shenandoah rivers in West Virginia, where the Blue Ridge Mountains meet the Appalachian Mountains.