Arguably, what makes the C&O Canal National Historical Park one of the most unique places in the National Park System is its geography. The C&O Canal is a linear park, and the towpath’s consistent width and smooth grade travels across four Maryland counties and the District of Columbia for 184.5 miles. The towpath is vital to the park’s identity, serving as the backbone for the recreational, cultural, and natural resources that all visitors come out to enjoy.
The towpath is continuous, meaning there are no breaks in the entire trail – at least, right now.
There have been moments in park history where there have been threats to towpath continuity. In 1972, Hurricane Agnes swept across the eastern United States, causing massive flooding along the canal. This storm caused significant damage. More than 200,000 trees had been ripped from the park, and 66 miles of towpath were damaged by the storm.
In 1996, there were two historic floods that took out a 2.7 mile section of the towpath near Big Slackwater, causing a five-mile detour for thru-hikers and bikers to the park. This “missing link” to towpath continuity remained in effect for nearly 15 years. In 2012, the National Park Service completed the Big Slackwater Restoration, after spending over $19 million to fix the breach. The project was funded through the American Recovery and Reinvestment Act and the Maryland Department of Transportation’s Transportation Enhancement Program, and donations from the C&O Canal Association, Washington County, Town of Williamsport and the Hagerstown and Washington County Convention and Visitors Bureau.
Recently, in spring of 2025, significant weather impacted the Mid-Atlantic region of the eastern United States. In some areas along the C&O Canal, the river crested over 20 feet, causing major damage to park structures. The flooding destroyed a section of the towpath in Oldtown, severing continuity. The NPS worked diligently to repair the breach, successfully completing the project in seven months. The restoration was made possible through the generosity of of donors to the C&O Canal Trust, including a $10,000 donation from Mountain Maryland Trails.
Towpath breach in Oldtown before repairs.
Rehabilitated towpath after repairs.
As the philanthropic partner to the park, the Trust works in tandem with the NPS to secure funding to support towpath continuity and rehabilitation. In 2016, an engineering study was conducted with the assistance of the Allegheny Trail Alliance (ATA). They found that the entire towpath urgently needed rehabilitation. The NPS put forth a plan to remediate the trail in sections with priority on areas where conditions of the trail have been most affected by potholes, drainage issues, roots, etc.
Since 2018, when the project first began, the Trust, in partnership with the NPS and the State of Maryland’s Transportation Alternatives Program (TAP), has supported rehabilitation for over 120 miles of the towpath. What does restoration look like? Rocks, roots, and other debris are removed before the trail is then degraded to facilitated water runoff. A crushed stone dust is then applied to the towpath’s surface, making it less likely to erode and rut.
As the towpath is the largest historic structure and the backbone of the park, its maintenance is critical to the park’s preservation. Together, we can continue to protect the park and its towpath. Through the Trust’s Towpath Forever fund, visitors to the park can help support the rehabilitation and continuity of the towpath.
Photos by Simon Barber, Francis Grant-Suttie, NPS, Chris Hanessian