Rockfish Gap is a wind gap located in the Blue Ridge Mountains between Charlottesville and Waynesboro, Virginia, United States, through Afton Mountain, which is frequently used to refer to the gap.Joining the Shenandoah Valley to the Piedmont region of the state, it is the site of the mountain crossing of Interstate 64, U.S. Highway 250, and the former Blue Ridge Railroad which later became part of the Chesapeake and Ohio Railway and is currently part of the CSX line.