C&O Canal Lock 20 | Montgomery County

C&O Canal Lock 20, also known as Tavern Lock, is a historically significant lock situated at mile 14.4 along the Chesapeake and Ohio (C&O) Canal Towpath in Great Falls, Maryland. This lock is part of a cluster of six locks (Locks 15 through 20) located near the Great Falls area, a region where the canal navigated challenging terrain through a series of elevation changes along the Potomac River. Lock 20 played a vital role in enabling canal boats to safely and efficiently traverse the steep elevation shifts caused by the nearby waterfalls and rugged river gorge.

Historical Context and Construction

Constructed in the early 19th century, Lock 20 was built as part of the ambitious C&O Canal project, which aimed to create a navigable waterway linking Georgetown (now part of Washington, D.C.) to Cumberland, Maryland. The canal was essential for transporting coal, lumber, agricultural goods, and other commodities during the 1800s, significantly contributing to the economic development of the region.

Lock 20’s design follows traditional canal lock engineering principles, incorporating hand-operated miter gates inspired by Leonardo da Vinci’s 15th-century design. These gates function by closing against each other to create a watertight chamber where water levels could be raised or lowered, allowing boats to ascend or descend approximately eight feet in elevation at this lock.

Architectural Features

Lock 20 is constructed from locally quarried Seneca Red Sandstone, known for its distinctive reddish hue and durability. This sandstone was a common building material for many canal structures in the region, including other locks, lockhouses, and the nearby Great Falls Tavern. The use of Seneca Red Sandstone links the lock to the geological and industrial history of the Potomac River corridor.

The lock structure consists of massive stone walls forming a rectangular chamber where boats would enter. The gates on either end were manually operated by canal workers, who controlled water flow through sluices to fill or empty the lock chamber. This engineering feat enabled boats to navigate the rugged terrain near Great Falls, where the Potomac River drops dramatically.

Great Falls Tavern and Lockhouse

Adjacent to Lock 20 is the historic Great Falls Tavern, built in 1828 initially as a lockhouse. The tavern provided lodging, meals, and social gathering space for canal boatmen, lock tenders, and travelers navigating the canal. It became a critical hub for commerce and rest in this remote and rugged section of the canal.

Today, the Great Falls Tavern operates as the Great Falls Tavern Visitor Center, offering interpretive exhibits and educational programs about the canal's history, engineering, and natural environment. The visitor center provides information on the role of Lock 20 and the surrounding locks, enhancing visitors' understanding of the canal’s operation and regional significance.

Canal Boat Demonstrations

One of the unique attractions at Lock 20 is the opportunity to witness or participate in canal boat rides aboard the Charles F. Mercer, a replica mule-drawn canal boat. During these rides, visitors can observe the locking process firsthand as the boat is guided through Lock 20. This hands-on experience demonstrates the practical mechanics of canal navigation and the labor-intensive work involved in moving goods and people along the waterway.

Visitor Access and Experience

Location: Lock 20 is accessible via the C&O Canal Towpath, a flat, multi-use trail ideal for walking, biking, and hiking. The towpath follows the canal's historic route and connects to other park features and trails in the Great Falls area.

Viewing and Access: A pedestrian footbridge spans Lock 20, allowing visitors to view the lock chamber from above and observe canal boats as they transit the lock. This vantage point offers excellent photographic and educational opportunities.

Facilities: The nearby Great Falls Tavern Visitor Center provides restrooms, informational exhibits, and park ranger assistance. Parking is available at the visitor center and surrounding areas.

Accessibility: The towpath and visitor center areas around Lock 20 are generally accessible for people with mobility challenges, though some historic structures may have limited accessibility due to their age and preservation status.

Importance and Preservation

Lock 20 is an integral part of the Chesapeake and Ohio Canal National Historical Park, preserving a crucial piece of 19th-century American engineering and transportation history. It stands as a testament to the ingenuity and effort required to build and operate the canal system, which shaped commerce and settlement patterns in Maryland and beyond.

The lock, along with the Great Falls Tavern and surrounding canal structures, is maintained by the National Park Service. Preservation efforts focus on maintaining the lock’s structural integrity, educating the public about the canal’s history, and providing opportunities for immersive, hands-on experiences that connect visitors to this historic waterway.

Summary

C&O Canal Lock 20 is a vital historic structure that exemplifies early American canal engineering. Built from Seneca Red Sandstone and equipped with classic miter gates, it facilitated boat navigation through one of the canal’s most challenging segments near Great Falls. Adjacent to the lock, the Great Falls Tavern provided essential services to canal travelers and now functions as a visitor center. Today, visitors can walk or bike along the towpath, explore interpretive exhibits, and experience canal boat rides that bring the history and mechanics of Lock 20 to life. The lock remains a significant cultural and educational resource within the Chesapeake and Ohio Canal National Historical Park, preserving the legacy of a critical transportation artery from America’s early industrial era.