Rockfish Gap is underlain by greenstones of the Catoctin Formation, a late Neoproterozoic geologic unit exposed throughout the Blue Ridge Mountains in Virginia, Maryland, and southern Pennsylvania.

[3] In the 18th century, early trails used by Native Americans were gradually expanded to accommodate the westward expansion of Virginia colonists.

[5] This well-planned route required only one major river crossing, the Rivanna at Charlottesville, with inns or taverns spaced about 10 miles apart.

This tunnel was later used by Confederate General Stonewall Jackson to move his foot cavalry during the 1862 Peninsula Campaign of the American Civil War.

[7][8] Rockfish Gap has been the site of several large multiple vehicle collisions on Interstate 64 during fog conditions on Afton Mountain, which peaks at about 1,915 feet above sea level.

A lighting system within the pavement to help designate lanes automatically activated by fog sensors was installed by the Virginia Department of Transportation (VDOT) to improve safety during such weather conditions.