History of Great Falls

History of Great Falls

July 19, 2002

From the National Park Service Website, www.nps.gov.

Today, the Great Falls of the Potomac stands as a natural wonder bringing awe and admiration of its power and beauty. In the mid-1700s the falls were seen as an obstruction to the navigation of the Potomac. Seeking a route to link the eastern seaboard with lands being settled in the Ohio valley, George Washington and other delegates solidified a plan to develop a system of canals on the Potomac, allowing navigation for over 200 miles. In 1785 the Patowmack Canal Company was formed, funds were acquired and construction began. Shallow areas had to be dredged and five bypasses and canals were engineered - at Little Falls, Great Falls, Seneca Falls, Shenendoah Falls, and at House Falls. The largest and most difficult to engineer was the Patowmack Canal of Great Falls and was completed in 1802. For 26 years the canal operated lifting and lowering river boats loaded with cargoes of corn, wheat, and rye flour, pig iron, tobacco, pork, beef, cast iron stoves and more. Considered to be the most significant engineering feat of the 18th century in America, the Great Falls Canal may still be seen in Great Falls Park. Information about the Canal Trail, our self-guided Patowmack Canal Brochure and ranger programs may be acquired at the park's visitor center.

In the early 1900s, two entrepreneurs by the names of John McLean and Steven Elkins, acquired the lands surrounding Great Falls and built an amusement park. Tourists traveled along a trolley from Georgetown to the park to see the spectacular Great Falls. Included in the park were overlook decks, an observation tower, a dance pavilion, a night light show, a wooden carousel, a Lovers' Lane along the Patowmack Canal ruins, and a foot bridge linking a rock island in the middle of the falls. The famous Dickies Inn provided lodging and exquisite dinners. The amusement park was an instant over-night success. Trolley cars were often full, selling tickets at 25 cents for five tickets. After the coming of the automobile and several floods, which severely damaged the park's structures, the amusement park eventually faded into history.

The land was eventually bought by the Potomac Power Company with plans to construct a hydroelectric dam. Fortunately, due to the hydrology and geology of the area the site at Great Falls was determined unfit for hydroelectric development. Fairfax County Park Authority leased the land and continued operating as a park, allowing the public to visit the Great Falls and ride the carousel. In 1966, through an agreement with Fairfax County, the National Park Service acquired the lands, totaling 800 acres. In 1968 the visitor center was built. In the following years, 15 miles of trails were constructed, and renovation of the Potowmack Canal locks were conducted. The National Park Service now administers Great Falls Park, preserving and protecting the resources and providing for recreation and enjoyment of the park.

Geological History of the Falls

From the National Park Service Website, www.nps.gov.

Located just 15 miles from the Nation's capital, the Great Falls of the Potomac (a name given the area by the first European colonists) is considered the most spectacular natural landmark in the D.C. metropolitan area. Here, the Potomac River builds up speed and force as it falls over a series of steep, jagged rocks and flows through a narrow gorge. This dramatic scene makes Mather Gorge, named after the first director of the National Park Service, a popular site with local residents and tourists from around the world who are visiting the Washington area.

The falls consist of cascading rapids and several 20-foot waterfalls with a total 76-foot drop in elevation over a distance of 3,500 feet. Arising from a calmer and much broader flow upstream, the Potomac constricts at Great Falls from 2,500 feet just above the falls to between 60 and 100 feet along the gorge for over a mile. The Great Falls of the Potomac display the steepest and most spectacular fall line rapids of any eastern river.

After the last ice age, the ocean levels dropped forcing the Potomac river to carve deeper in its path to the sea. The overlying rock was eroded away exposing a much harder, resistant rock formation called the Piedmont. This hard layer is principally made up of highly metamorphic and igneous rock, and may be seen throughout the park.

For thousands of years the Potomac river has eroded the bedrock, causing the falls to recede upstream from a point 9 miles downstream near Chain Bridge to its current position at Great Falls. Joint fault plains, natural fissures in the rock substrata where shifting has occurred, exist in many places in the Piedmont Formation between Chain Bridge and the Great Falls. These areas of faulting have loosened the rock, forming areas of weakness. The force of the river has eroded along these areas changing the river's course to its current position.

As one walks along the cliff tops, evidence of the ancient riverbeds can be seen in well-rounded boulders, smoothed surfaces and grooves, and beautifully formed potholes, which were once formed on the ancient riverbed. The metamorphic rocks provide jagged rocky surfaces and high-walled cliffs, stark and pristine against the crashing waters of the Potomac at the falls and along Mather Gorge.