This Canal Towpath Disappears Into a Mountain at the Paw Paw Tunnel
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The Paw Paw Tunnel C&O Canal passage is a brick-lined historic route where you can walk through a dark mountain tunnel or climb the strenuous trail above it. The short tunnel walk suits visitors who want canal history, while the ridge route calls for more time and effort.
You can also enjoy river scenery from the towpath and ridge. The site sits within Chesapeake and Ohio Canal National Historical Park, where the old waterway meets a rugged stretch of the Potomac. Weep holes are small openings in masonry that let water escape from behind the brick lining.
Key Takeaways
- Walk through the historic tunnel or climb the Tunnel Hill Trail.
- The ridge route is steep and strenuous.
- Parking is at Paw Paw Tunnel Campground.
- The passage has no artificial lighting, so bring a flashlight.
- The tunnel is open dawn to dusk year-round.
- Check park conditions before you travel.
Choose between a brief tunnel visit and a longer ridge hike based on how much time and effort you want to spend outdoors.
How Was the Paw Paw Tunnel Built?
In 1836, the Chesapeake and Ohio Canal Company expected the tunnel to be finished in just two years. Lee Montgomery received the construction contract that year, but crews faced hard shale, labor disputes, and long stoppages.
The company expected the tunnel to cost $33,500 and take two years. Instead, construction lasted 14 years, with workers removing more than 200,000 cubic yards of rock and soil.
Hard shale and repeated work stoppages turned a two-year plan into a 14-year project.
Why the project fell behind
Workers dug from both ends with hand tools and black-powder blasts. Immigrant laborers did the difficult excavation and masonry work under harsh conditions.
Shale slowed each advance. Crews moved forward about 12 feet per week, a slow pace for a passage through a mountain.
Labor disputes also disrupted the job. Work stopped for six years, leaving the tunnel unfinished while the canal company struggled to keep the project moving.
Those delays explain why the construction schedule stretched so far beyond its original target. The company had planned a short job, but the rock and labor problems kept crews away for years.
From construction site to canal landmark
After the long stoppage, workers returned to finish the excavation and prepare the passage for canal use. They opened it before the brick lining was complete.
Crews later lined the tunnel with brick. The unfinished interior at opening reflects the order of work: the passage first had to be cut through the ridge, then finished for lasting use.
The tunnel became a key part of the canal route through a difficult stretch of mountain terrain. Its construction shows how much work canal builders took on to keep the waterway moving.
The 14-year effort ended with the tunnel opening in October 1850, though its brick lining was finished afterward.
What Makes the Paw Paw Tunnel C&O Canal Passage Unique?
The tunnel let canal builders cut through the ridge instead of following the Potomac River’s six-mile Paw Paw Bends. That shortcut avoided the need to build six miles of canal beside a winding river stretch.
The passage is 3,118 feet long and lined with an estimated six million bricks. Its enclosed route feels very different from the open river bends and the mountain ridge above.
The Paw Paw Bends forced canal planners to choose between a long route beside the river and a direct cut through the mountain. A tunnel gave boats a straighter passage, while the Potomac continued around the bends below.
From the canal towpath, the tunnel’s brick walls make the scale of that choice clear. The river bends offer a broad, exposed view; inside, the passage narrows into a long corridor with masonry overhead.
The two entrances also tell different stories. The western entrance has been changed, while the eastern entrance keeps its historic appearance.
Weep holes in the brickwork let water escape from behind the lining. Along with the dark walls, they help show that the passage is a built structure, not a natural cave.
Visitors can see how the canal route passes through the ridge rather than around it. The contrast between the narrow passage and the open river landscape is part of what makes this spot memorable.
The passage is long enough that its dark interior feels like a separate walk, not just a doorway through the hill.
Which Trail Route Should You Take?
For a strenuous ridge walk, take the Tunnel Hill Trail; for a longer outing that combines the ridge and towpath, use the 4.8-mile out-and-back route. The ridge climb is steep and strenuous, while the towpath is nearly level.
Choose by effort as well as distance: the ridge adds a sustained climb, and the towpath gives you a gentler way to reach the tunnel.
The Tunnel Hill Trail
The Tunnel Hill Trail runs for two miles and connects with the towpath at both ends. It climbs steeply over the ridge, so allow for a demanding walk even though the route is relatively short.
River viewpoints reward the climb. You can look out over the Potomac and the wooded terrain around the Paw Paw Bends, then descend toward the canal path.
Trail names can be confusing on maps and signs. Tunnel Hill Trail refers to the ridge route, while “Paw Paw Tunnel Trail” may describe a longer outing that also uses the towpath.
The longer out-and-back route
The listed Paw Paw Tunnel Trail route covers 4.8 miles out and back, with 784 feet of elevation gain. It takes an estimated 2 to 2.5 hours, depending on your pace and stops.
A route map helps you see where the ridge section begins and where the towpath takes over. Check the line of the route, not just its name, so you know whether your plan includes the steep hill.
The combined outing gives you both the ridge views and a walk beside the canal. It asks more of your legs than a towpath-only visit, especially on the uphill sections.
If you enjoy longer outdoor outings with fewer crowds and limited cell service, browse these backcountry destinations for a week away.
A towpath-only visit
You can stay on the nearly level C&O Canal towpath and walk through the tunnel without taking the ridge climb. This option keeps the outing simple while still giving you time inside the historic passage.
The towpath suits visitors who want to avoid steep grades or keep the walk shorter. You can turn back when you have seen enough, rather than committing to the hill trail.
Match the route to your comfort with steep climbs, since the towpath and ridge demand very different effort.
Where Do You Park for the Paw Paw Tunnel?
Park at Paw Paw Tunnel Campground, then walk 0.5 miles to reach the tunnel. The parking lot is free, and overnight parking is allowed.
The tunnel has no street address, so searching for Paw Paw Tunnel Campground is a practical way to set your destination. GPS coordinates for the lot are 39.544188, -78.460900.
MD-51 reaches the campground from both nearby towns. The lot sits on a different side of the road depending on which direction you approach.
- Navigate to Paw Paw Tunnel Campground.
- Approach on MD-51 from Cumberland or Paw Paw.
- From Cumberland, travel about 24 miles; the lot is on the left. From Paw Paw, travel about 0.5 miles; the lot is on the right.
- Walk 0.5 miles from the campground to the tunnel.
From Cumberland, Maryland, follow MD-51 for about 24 miles toward the campground. Watch for the parking area on your left as you approach.
From Paw Paw, West Virginia, follow MD-51 for about half a mile. The parking lot is on your right.
Give yourself time for the walk from the campground. The lot is the starting point for reaching the tunnel, not a place beside its entrance.
Save the campground destination before leaving, since the tunnel itself has no street address.
What Should You Know Before Entering the Tunnel?
The tunnel has no artificial lighting, so bring a flashlight before you step inside. A flashlight is recommended for the dark middle of the passage.
The brickwork holds small clues to the tunnel’s past. Look closely at the walls, where old marks and numbered plates help make the walk more than a dark crossing.
Historic details inside the brick passage
Weep holes are small openings in masonry that let water escape from behind the brick lining. You can also look for rope burns, rub rails, and brass plates marking each 100 feet.
- Weep holes: openings that release water behind the brick lining.
- Rope burns: marks left by canal boat ropes.
- Rub rails: wall features that helped protect boats.
- Brass plates: distance markers set every 100 feet.
These details give you clear points to notice along the way. The plates can help orient you, while rope burns and rub rails hint at how boats moved through the passage.
For tunnel or trailhead photos, use the brickwork and plates as visual guides. Their repeated shapes can add scale to a view of the interior.
Rules for people, bikes, and horses
Bicyclists must dismount in the tunnel and on boardwalks. Horses are not allowed inside the tunnel, so riders cannot use the passage.
The rules differ by visitor type, especially for horses at the tunnel entrance. Keep this quick comparison in mind:
| Visitor | Tunnel rule | Boardwalk rule |
|---|---|---|
| Walkers | Carry a flashlight | Walk through |
| Bicyclists | Dismount | Dismount |
| Horses | Not allowed in tunnel | No tunnel access |
Walkers should keep their light ready before entering the unlit middle of the passage.
How Does the Paw Paw Tunnel Fit Into C&O Canal History?
The C&O Canal means Chesapeake and Ohio Canal, a 184.5-mile waterway completed to Cumberland in 1850. Construction began in 1828 and took about 22 years.
The canal stopped at Cumberland rather than reaching its original planned destination, Pittsburgh. Its towpath and waterway formed a route linking Georgetown with western Maryland.
What the canal name and route mean
The C&O Canal name describes the Chesapeake and Ohio route the builders hoped to create. The finished canal reached Cumberland, not Pittsburgh, after decades of work.
The 184.5-mile towpath from Georgetown to Cumberland follows the canal from Mile 0 in Georgetown to Mile 184.5 in Cumberland. You can walk its length in stages or follow a shorter stretch near the tunnel.
The canal joined a period of major waterway building in the United States. Its full route gives the Paw Paw passage a wider role: it helped boats cross a hard stretch between the river and the ridge.
How the waterway worked
The towpath ran beside the canal so people or animals could pull boats along the water. Locks raised or lowered boats between water levels, allowing them to move across changes in elevation.
The canal prism is the channel that held the water. Its original depth was six feet, and its original width ranged from 60 to 80 feet.
The South Hadley Canal offers an earlier comparison. It was the first navigable canal completed in the United States, in 1795.
| Canal feature | Measurement | Extent | Purpose |
|---|---|---|---|
| Towpath | 184.5 miles | Georgetown to Cumberland | Route alongside the canal |
| Locks | 74 | Along the canal | Raise or lower boats between water levels |
| Prism | Originally 6 feet deep and 60-80 feet wide | Canal channel | Held the navigable water |
The prism’s original depth and width show the size of the channel boats needed to travel through.
The South Hadley Canal was completed in 1795 as the first navigable canal in the United States.
Can You Walk or Swim Along the C&O Canal?
You can walk the C&O Canal towpath, but swimming rules depend on whether you are in canal water or the Potomac River. Swimming is prohibited in canal waters.
The towpath runs 184.5 miles from Georgetown to Cumberland, so you can explore it in stages instead of walking the full route at once. Pick a stretch that fits the time you have.
Rules for the river differ by park location. Potomac River swimming is prohibited in the park’s Washington, D.C., and Montgomery County, Maryland, sections.
- Swimming is prohibited in canal waters.
- Potomac River swimming is prohibited in the park’s Washington, D.C., and Montgomery County sections.
- Check local park signs before entering any water elsewhere.
The Paw Paw Bends sit along a river stretch where the canal route cuts through the ridge. Nearby water does not mean the same rules apply everywhere in the park.
Check the local park signs before planning any water activity, because the Potomac rule applies to specific park sections.
When Is the Paw Paw Tunnel Open?
Paw Paw Tunnel is open dawn to dusk year-round, though the south portal looks different in colder months. A doorway remains open for public access when boards cover the portal.
The boards act as a windbreak during colder weather. The entrance may look closed at first, but the open doorway allows people to enter.
In colder months, use the open doorway in the boarded south portal for public access.
The Tunnel Hill Trail is listed as open year-round. The tunnel’s dawn-to-dusk hours still shape when you can walk inside.
Park crews maintain the structure to keep the historic passage in use. Repairs have included replacing fallen bricks, filling towpath cavities, stabilizing rock slides, and repairing the downstream portal.
Maintenance work can affect conditions around the route, even when the site remains open. Check current park conditions before you travel, especially if you plan to travel through the tunnel rather than turn back at the portal.
Conclusion
Paw Paw is worth planning around whether you want a short canal-history stop or a demanding hike with river views. The tunnel gives you a close look at the canal’s route through the mountain, while the ridge adds a different view of the river and towpath.
Decide how much climbing you want, then save the route that fits your visit. Check current park conditions before setting out, since access details can change with weather and repair work.
Save the park’s current route and access information before you leave home.
