Chesapeake and Ohio Canal National Historical Park

The Chesapeake and Ohio Canal National Historical Park preserves 184.5 miles of the historic C&O Canal and its towpath along the Potomac River from Georgetown in Washington DC to Cumberland, Maryland — one of the longest, most linear and most accessible linear parks in the eastern United States, a historic waterway canal (operating from 1831 to 1924) whose towpath now serves as a premier hiking, cycling and nature trail through the Potomac River gorge, the Blue Ridge foothills and the Cumberland Valley.

The towpath passes through Great Falls (where the Potomac plunges through a dramatic gorge — the most spectacular natural feature near Washington DC), Harpers Ferry (the famous Civil War and John Brown site), and the dramatic Paw Paw Tunnel (a 3,100-foot canal tunnel through Paw Paw Bends). The canal’s locks, lockhouses, aqueducts and tunnel are remarkable feats of 19th-century engineering. The C&O Canal NHP is a treasured natural and historical icon of Maryland.

The C&O Canal NHP offers cycling the full 184.5-mile towpath (a premier long-distance trail — flat, crushed limestone, through dramatic river gorge and Maryland landscape), hiking the towpath in segments (excellent day hikes near Great Falls, Swains Lock, Harpers Ferry and the Paw Paw Tunnel), kayaking and canoeing the Potomac River (particularly in the flatwater sections above Great Falls and below Cumberland), rock climbing and bouldering at Great Falls (some of the finest sport climbing near Washington DC), wildlife watching and birding (bald eagles, ospreys, great blue herons, prothonotary warblers along the canal corridor), and camping at hiker-biker campsites along the full towpath. The Great Falls overlook, the towpath cycling route, and the Paw Paw Tunnel are the signature draws.

Spring (March through June) is the most beautiful season on the towpath — the Potomac river wildflowers bloom along the towpath, the warblers arrive in the riparian forest (including the brilliant orange-and-yellow prothonotary warbler in the lockhouse swamps), the Great Falls spring runoff creates the most dramatic gorge scenery, and the temperatures are ideal for cycling. Fall brings the Potomac hardwood color. Summer is hot but the gorge sections are shaded; Great Falls is spectacular after summer storms. Spring for the wildflowers and birdsong, and fall for the color, are the highlights.

The Chesapeake and Ohio Canal was conceived as a water route connecting the Chesapeake Bay (at Georgetown) to the Ohio River (at Pittsburgh), carrying the commerce of the interior across the Appalachians. Construction began in 1828 (the same day as the Baltimore and Ohio Railroad, which would ultimately make the canal obsolete). The canal was extended to Cumberland in 1850 but never reached Pittsburgh. It operated, carrying coal from the Alleghenies, until a devastating flood in 1924 ended commercial operation. Justice William O. Douglas organized a famous 1954 hike of the towpath to prevent its conversion to a highway, helping establish it as a national historical park in 1971. The canal’s locks, aqueducts and lockhouses are a remarkable preserved industrial heritage.

The C&O Canal’s route follows the Potomac River gorge through some of the most geologically significant terrain in the mid-Atlantic — the Great Falls of the Potomac (where the river drops 76 feet through a gorge carved in Mather Gorge schist and Metagraywacke, ancient metamorphic Precambrian rocks exposed by the river’s downcutting) and the Blue Ridge through Harpers Ferry (where the Potomac and Shenandoah Rivers cut through the Blue Ridge quartzite in the famous ‘view that repays the trouble of travel’ that Thomas Jefferson described). The Paw Paw Bends are in Silurian-age shales.

The C&O Canal corridor is a nationally significant wildlife corridor along the Potomac River — nesting bald eagles (common along the river), osprey (nesting on every major river bend in season), the brilliant prothonotary warbler (nesting in the flooded willow swamps along the canal), great blue herons, great horned owls, pileated woodpeckers, white-tailed deer, river otters, and a rich diversity of Appalachian migratory songbirds in the riparian forest. The Great Falls section and the flooded canal sections are the richest wildlife areas. The towpath is a birding trail of regional significance.

The C&O Canal corridor protects 184.5 miles of Potomac River riparian forest and historic waterway, one of the most significant linear greenway corridors in the eastern US. The canal’s flooded sections provide prothonotary warbler and wood duck habitat. The Great Falls Potomac gorge is a Registered Natural Landmark. The Potomac River and its riparian forest are shared among Maryland, Virginia and Washington DC; protecting the water quality and the wildlife corridor requires regional cooperation. Invasive plants (Japanese honeysuckle, garlic mustard, mile-a-minute vine) are significant threats to the native riparian flora.

The Chesapeake and Ohio Canal National Historical Park holds a treasured place among the icons of Maryland, Washington DC and the mid-Atlantic — a 184.5-mile linear park of historic waterway, Potomac River gorge, and 19th-century engineering infrastructure, the finest long-distance cycling and hiking trail in the region, and the site of Great Falls — the most spectacular natural feature near the nation’s capital. The canal’s history, the dramatic Potomac gorge and the towpath trail together make the C&O one of the most beloved parks in the eastern US. It is a cherished natural and cultural icon.

The C&O Canal NHP runs from Georgetown (Washington DC) to Cumberland, Maryland, 184.5 miles. The main access points for day visitors are the Great Falls Tavern Visitor Center (in Maryland, off MacArthur Boulevard near Potomac, MD — about 15 miles from downtown DC; the most visited section), the Georgetown entrance (the eastern terminus, at the Georgetown waterfront), and Harpers Ferry (West Virginia, accessible by the Appalachian Trail bridge from the Maryland side). The full towpath is accessible from dozens of road crossings. Check the NPS for current visitor center hours, campsite reservations and conditions before visiting.

The National Park Service manages the C&O Canal NHP. Invasive plants are a major management challenge along the towpath; volunteers are essential for removal. The Potomac River water quality, the flooding that damages the towpath (the towpath is frequently damaged by Potomac floods and requires ongoing maintenance), and the natural flooding of the Great Falls gorge are primary management considerations. Visitors help by staying on the towpath and designated trails, packing out all trash, respecting the historic structures (do not enter closed lockhouses without authorization), and reporting invasive plants to the park. Support the C&O Canal Trust (the park’s nonprofit partner) for trail maintenance.

The Potomac River above Great Falls is deceptively calm but extremely dangerous — never wade or swim in the Potomac above Great Falls (powerful underwater currents, smooth rocks and an invisible hydraulic that has killed dozens of people who ignored this warning). Below Great Falls the river is also dangerous in high-water conditions. Rattlesnakes and copperheads are present on the rocky sections of the Maryland heights. The towpath can be flooded and impassable after heavy rain. Cycling the full towpath requires camping and multi-day preparation. Respect the Potomac hazards above Great Falls above all other safety concerns at this park.

The towpath and most areas are free; the Great Falls parking area has a fee. Camping at towpath hiker-biker sites is free; reservations through recreation.gov required for some sites. Bicycles on the towpath (no motorized vehicles). Dogs must be leashed. No swimming in the Potomac above Great Falls (posted). Fires only in designated fire rings at towpath campsites. Hunting is not permitted in the NHP. Check the NPS for current towpath conditions (flooding frequently closes sections) before any trip.

The Great Falls of Virginia (across the Potomac in Great Falls Park, NPS — a complementary Virginia-side view of the same falls), Harpers Ferry National Historical Park (at the western end of the Maryland heights), Seneca Creek State Park, the city of Cumberland (the western terminus, with the Western Maryland Scenic Railroad), and the full Potomac River corridor from DC to Cumberland define the region. The C&O Canal towpath connects Washington DC to the Appalachian highlands of western Maryland in an unbroken linear greenway, the finest multi-day cycling trail in the mid-Atlantic.

Walk or bike from the Great Falls Tavern Visitor Center upstream to the Great Falls overlook (0.5 miles) for the most dramatic view of the Potomac — the 76-foot falls plunging through the Mather Gorge is the finest natural spectacle near Washington DC. Cycle the towpath from Georgetown to Harpers Ferry (about 62 miles, 2 days) for the finest towpath cycling experience — stay at the towpath hiker-biker campsites and end at the dramatic Harpers Ferry overlook. Look for the brilliant yellow prothonotary warbler (a cavity-nesting warbler) in the flooded canal sections at Swains Lock and Hughes Hollow in May — one of the most beautiful birds in the eastern US.