• Historic Shot of Canal Boat on the Canal

    Chesapeake & Ohio Canal

    National Historical Park DC,MD,WV

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  • NEW Overnight parking system

    Before parking a vehicle overnight in any Canal Parking area, visitors must register their vehicle through the new online registration system. Print your reciept and place on your dashboard. If unable to print, please visit the nearest visitor center. More »

  • Water Pump Handles Temporarily Removed

    Water pump handles at Bald Eagle Island, Jordan Junction and Big Woods Hiker Biker Campsites have been removed due to bad water samples. Handles will be reinstalled when good water samples are received.

  • Boat Tours at Great Falls

    Due to low water levels in the Great Falls area, call the Great Falls Tavern Visitor Center (301-767-3714) in advance of your trip to confirm the mule-drawn boat tour schedule.

  • Parking Lot Closure

    CSX is now beginning a phase of their bridge project that requires the closure of the Lock 74 parking lot for approximatly 18 months. Access to visitor parking near Lock 75 is now re-opened with a gravel parking lot at the site.

Big Slackwater

river construction

Construction of one of the new sections of towpath was done from barges on the Potomac River.

For up-to-date information on the status of Big Slackwater visit our Facebook page. Click on the Events tab to check on the opening status. Or check out the Big Slackwater webpage to view construction photos, and RSVP for the Ribbon Cutting Ceremony on Saturday, October 13, 2012 at 10:00 a.m.


With little maintenance between 1924 and 1971 when the National Historical Park was created, this stretch of the towpath was particularly vulnerable to flood waters. In 1996 two large floods dealt a devastating blow completely washing away long stretches of the towpath causing all towpath visitors to endure a 5-mile detour. Since then the enormity of the erosion prevented the repairs to Big Slackwater making it the only segment of the 184.5-mile canal towpath closed to park visitors.

Restoration of the Big Slackwater area is a culmination of more than 15 years of work by park staff, citizen stewards and park visitors. This project reestablishes the continuity of the entire 184 ½ mile towpath. Restoration of the towpath to its original alignment along the Potomac River and above Dam No. 4 not only eliminates the hazardous detour along narrow country roads but it restores the magnificent views and historic route walked by mules and canawlers.

The Big Slackwater restoration contract was over $19 million and was primarily funded through the American Recovery and Reinvestment Act and the Maryland Department of Transportation's Transportation Enhancement Program, with donations from the C&O Canal Association, Washington County, Town of Williamsport and the Hagerstown and Washington County Convention and Visitors Bureau.


9/22/2012 - Big Slackwater is now OPEN to the public! Visitors can access at Burnside or Dam 4 area. McMahon's Mill access is still closed. Use extreme caution riding this section as it is very narrow and there are no guard rails. Obey the speed limit and slow down when passing others to avoid accidents. Remember to RSVP for the ribbon cutting ceremony on October 13.

Did You Know?

School bus at Williamsport

Our park partners--the C&O Canal Trust and the C&O Canal Association--offer scholarships to schools to pay for buses. More...