Long before the first plants took root to cover them with a soft layer of green, huge gray peaks — probably not unlike those of the Rocky Mountains — once towered where the rolling Piedmont exists today.
Over hundreds of millions of years those ancient peaks, built of powerful metamorphic rock, slowly disappeared, and the newer Appalachian Mountains grew to their west.
Giant rivers eventually formed, carrying silt eroded from the Appalachians across the vanishing pre-Piedmont peaks, depositing the material to the East. That sediment formed today’s Coastal Plain, the flatter land that surrounds the modern Chesapeake.
But remnants of the long-lost Piedmont mountains can be seen today: They are the hard rocks that form the “fall line,” a set of waterfalls that mark the limit of navigation on every major Western Shore river of the Bay watershed.
Early explorers, such as Capt. John Smith, and later trading ships, were halted at the fall line. Where the ships were stopped, cities grew: Richmond, Fredericksburg, Washington and Baltimore.
But nowhere is the fall line more evident — and dramatic — than at Great Falls, barely a dozen miles up the Potomac River from Washington, D.C. In fact, geologists actually label the area along the Potomac the “fall zone” as it stretches more than 10 miles, from Great Falls to Little Falls, just outside Washington.
Great Falls Park, administered by the National Park Service, tells the story of how the fall line was formed, as well as how efforts to build a canal around the ancient geologic obstacle helped to link a young nation. The park, on Virginia’s side of the Potomac, is one of the newest sites in the Park Service’s Bay Gateways Network, which showcases natural, historic and cultural sites around the Bay.
When visitors to Great Falls stand at overlooks today, they marvel at the falls — cascading through and around metamorphic rock formations — which somehow look out of place just a few miles upstream of the wide, tidal river that runs past the nation’s capital.
Its dramatic cliffs and spectacular views draw picnickers, hikers and rock climbers. Advanced kayakers take on its Class VI rapids — the most advanced. “This is a playground for kayakers,” said Park Ranger Brent O’Neill. “But you’ve got to be very advanced to get on the river at this level.”
Great Falls is the farthest upstream that shad and herring can migrate on the river. For hundreds of years, Native Americans would gather at the base of the falls, harvesting fish and conducting trades.
But when George Washington first visited the falls, he saw them not as a meeting place, but as a barrier to trade and western movement. He spent much of his life trying to find a way around them. In 1772, he and Harry Henry “Light-Horse Harry” Lee were authorized by the Virginia legislature to form a Potomac navigation company to deal with the problem. But the venture was opposed by Maryland, which owned the river.
Soon, the Revolution broke out; Washington and Lee went on to become war heroes. While some may believe that Washington’s early interest in the canal was prompted by his ownership of land to the west. But after the war, he was clearly convinced that an improved route to the West was critical to bind the fragile nation together.
In 1784, he lamented in a letter to Benjamin Harrison that the young nation’s hold on western settlements was so fragile that “the touch of a feather would turn them away.” The same year, he wrote Thomas Jefferson that “not a moment ought to be lost in recommencing this business.” He also warned that western inhabitants already contained a large number of foreigners, “and a Commercial connexion is the only tie we can have upon them.”
Washington hosted a meeting of leaders from both states at Mount Vernon in 1784, which led to an agreement that allowed the project to go forward.
The effort to hammer out interstate problems was so successful that Maryland and Virginia officials agreed to meet in Annapolis the next year to deal with other interstate issues, this time inviting representatives from all of the states. It was the first in a series of meetings that culminated in the U.S. Constitution.
In 1785, before he became president of the United States, Washington became president of the newly formed Pawtomack Company, which was to build the canal.
“I call this George Washington’s most personal landmark,” O’Neill said. Indeed, the general threw himself into the project. Washington spent a large amount of time scouting the river with engineers and others, planning the transportation route. At the time, canals were almost nonexistent on the continent, and the Potomac had a number of significant impediments to navigation, not only at Little Falls and Great Falls, but upstream as well.
The Patowmack canal was not a continuous ribbon of water, like the canals that would begin running across the nation a few decades later. Rather, it was a series of short canals and locks that would bypass the river’s navigational barriers. That, in turn, would allow boats to travel between Cumberland, MD and the tidal Potomac.
Washington and his engineers debated which obstacles could be avoided with a bypass — such as with a mile-long canal around Shenandoah Falls at Harpers Ferry — and where engineers would have to build locks to lift and lower boats. Locks, at that point in time, had never before been used in North America. Ultimately, five locks were needed along the mile-long route around Great Falls, where the river dropped 77 feet, and three more around Little Falls and its 38-foot drop.
The engineering feat was unprecedented: Two back-to-back locks at Great Falls rose 18 feet each. The largest locks in Europe at the time were only 7–10 feet. In places, workers blasted their way through solid rock, marking the first time that black powder was used for blasting purposes in the United States.
The work was hard and often dangerous. Finding reliable workers was difficult. The company sought to entice men with alcohol, which yielded its own set of problems. Indentured servants proved unreliable, and would often run away. Eventually, much of the canal was built by slaves hired out for the project. “They were more reliable and they worked hard,” O’Neill said.
Construction began in 1785, but the project was not completed until 1802, three years after Washington died. Yet it accomplished its mission of linking the East and the West through commerce: Boats could traverse the 190 miles from Cumberland to Georgetown in just four days. At that point, rivermen would usually dismantle and sell their boats as lumber, then walk home.
The canal remained in use for 26 years, but it never proved to be a sound investment for shareholders. It turned a profit only during its first full year of operation. While the bypass canals allowed boats to safely get around obstacles, the river itself proved to be too shallow much of the time to support navigation between the bypasses on long stretches of the river.
That ultimately led to the Patowmack Company dissolving into bankruptcy in 1828, with its assets being transferred to the new Chesapeake and Ohio Canal. Built on the Maryland side of the river, the C&O ran parallel but separate from the river, and therefore was able to maintain enough water to float boats year-round.
The end of the canal also spelled doom for a small town that had grown up alongside it at Great Falls. Matildaville was the dream of Henry “Light Horse Harry” Lee, and was named for his wife. Lee hoped canal traffic would support a prospering village, but it didn’t survive much beyond the days of the canal.
One business, Dicky’s Inn, continued to flourish for nearly a century. “They boasted that every president from George Washington through Theodore Roosevelt enjoyed a nice chicken dinner there,” O’Neill said.
The grounds of Matildaville later became part of an amusement park. The path along the old canal was the park’s “Lover’s Lane.” Visitors today can walk that same path as they examine the overgrown ruins of what was once Matildaville. They can also explore the rock chasm blasted for the two 18-foot-vertical locks. In places, the holes drilled into the rock for the placement of black powder can still be seen.
Just as ancient mountains have eroded into remnants, so, too, has the canal that was built to bypass them. The Patowmack Canal has been largely filled in by floods and erosion, although portions have been restored and are maintained by the National Park Service.
But a walk along the parts that remain offers a subtle reminder that not long ago, the link between the Coastal Plain’s wide, tidal rivers and the faster-flowing freshwater rivers and streams that dominate the rest of the watershed, was not nearly so clear as it is today.
Great Falls Park is open every day except Christmas. From April 15 through Oct. 15, the Visitor Center is open 10 a.m. to 5 p.m. weekdays, and 10-6 on weekends. The rest of the year, it is open 10-4 daily. The park closes at dark and the gates are locked. There is a $5 per vehicle entrance fee.
The Visitors Center features a 10-minute slide program, “History of Great Falls,” and a three-dimensional model of the Great Falls and Patowmack Canal and a preserved piece of a canal lock gate. Other displays highlight George Washington’s role as a leader in establishing the canal; geologic features of the Potomac River Gorge and Great Falls, flooding and recreational sports. A children’s room provides hands-on nature and other activities.
To get to the park: From the Washington Beltway in Virginia, take Exit 44, onto Route 193, which is also named Georgetown Pike. Take 193 west. Turn right at Old Dominion Drive (after about 4.5 miles), then straight 1 mile to entrance station.