Potomac River Gap

Home » Appalachian Mountain Gaps » Potomac River Gap

Potomac River Gap

  • Elevation: 247 feet (75 meters)
  • Coordinates: 39°31′39″N 78°35′15″W

The Potomac River water gap at Harpers Ferry, West Virginia, provided a vital and accessible passage through the Appalachian mountain barrier at an elevation of 247 feet (75 meters), making it the lowest point in the state. The gap is geographically situated at the confluence of the Potomac and Shenandoah Rivers. The ancient Potomac carved a steep-walled channel straight through the rising Blue Ridge Mountains, creating a rare, natural, water-level route that was critical for westward expansion.

For the Baltimore & Ohio (B&O) Railroad in the 19th century, this gap was key for its route to the Ohio River Valley. The B&O followed a “water level route” that simplified engineering challenges, initially running along the Patapsco River valley before turning to the Potomac valley. The railroad then ran along the Potomac’s north bank for much of the journey, competing for the narrow strip of land with the Chesapeake & Ohio (C&O) Canal Company. This bitter rivalry forced a legal battle in 1832, which the canal company won, but the railroad and canal ultimately reached an agreement.

At Harpers Ferry, where the Shenandoah meets the Potomac, the B&O was forced to bridge the river to continue its westward route. The railroad constructed an 830-foot covered wooden truss bridge in 1837, establishing a crucial junction with the Winchester and Potomac Railroad.

The town and its strategic rail line became a major military objective during the Civil War, changing hands between Union and Confederate forces at least eight times. The B&O’s successful navigation and reconstruction through the Potomac water gap proved to be a critical factor in establishing a reliable transportation link westward, solidifying its position as a major railroad. After passing through the gap, the B&O mainline continued along the river’s west bank from Cumberland, heading inland toward Martinsburg.

For More Information – Sources and Resources

The following are excellent resources for those of you wanting to explore and learn more about the history and operation of the Appalachian Railroads. These sources of information also serve as reference and historical materials for Appalachian-Railroads.org. Much of the content on the website is verified across multiple sources.

Contact Us

Would enjoy hearing from you if you have questions, suggestions, edits, or content that you are willing to share. Don’t hesitate to reach out if you have similar interests in the railroads or model railroading.

Go back

Your message has been sent

3Cs Websites

Appalachian-Railroads.org | Clinchfield.org | Southern-Railroads.org