The Blue Ridge runs all the way from Pennsylvania to Georgia, touching only the easternmost tip of West Virginia in Jefferson County, where its crest forms the border with Virginia.

The Blue Ridge contains the oldest surface rocks in the state. The very oldest is the Catoctin greenstone, formed from 600-million-year-old lava flows that were later squeezed and changed by geologic pressure.

The mountain is separated from the Allegheny Mountains by the Shenandoah Valley. The lowest point in the entire state is where the Shenandoah and Potomac rivers meet, cutting a dramatic gap (pictured) through the Blue Ridge at Harpers Ferry (only 247 feet above sea level).

For early European-American settlers, the Blue Ridge was a tough barrier to moving west. Most early immigrants came into what’s now West Virginia through the passes found to the north, especially the easy passage at Harpers Ferry.

The Harpers Ferry gap was vital for transportation. Both the Chesapeake & Ohio Canal and the Baltimore & Ohio Railroad were built through it, and controlling this passage was a key goal during the Civil War.

The Appalachian Trail follows the crest of the mountain, and the trail's national headquarters is located in Harpers Ferry.