The Chesapeake & Ohio Canal towpath stretches 184.5 miles from Cumberland, Maryland, to Washington, D.C., and it is one of the longest continuous walking and biking routes in the Mid-Atlantic. This guide pulls together what the National Park Service says about the route, its famous brick tunnel, free hiker-biker camping and entrance fees, so late-fall visitors know what to expect.
What is the C&O Canal towpath?
The Chesapeake & Ohio Canal National Historical Park follows the Potomac River through the District of Columbia, Maryland and West Virginia, according to the National Park Service (NPS). The canal itself was a working transportation route for “nearly 100 years,” carrying coal, lumber and farm products to market, the agency says.
Mules were the “engines” of the canal boats, hauling goods and people along the towpath between Georgetown and Cumberland. That towpath, the narrow strip beside the water where the animals walked, is what visitors use today. The park’s basic-information page says it “stretches 184.5 miles.”
Highlights the NPS names include Great Falls, Paw Paw Tunnel and the stretch known as Big Slackwater above Dam 4. Bicycling is allowed on the towpath, as well as on the Western Maryland Rail Trail, the Capital Crescent Trail and Berma Road. The agency also points hikers to the Billy Goat Trail.
Quick facts
| Item | What the NPS says |
|---|---|
| Towpath length | 184.5 miles, Cumberland to Washington, D.C. |
| Paw Paw Tunnel | Mile 155.2; 3,118 feet long |
| Tunnel construction | Began 1836; opened October 1850 |
| Commercial shipping ended | 1924 |
| Federal acquisition | 1938 |
| Hiker-biker campsites | Free, first-come, first-served, one night per trip |
| Drive-in campsites | $20 per site per night, reserved through Recreation.gov |
| Park office | Williamsport, Maryland, 301-739-4200 |
Why is the Paw Paw Tunnel such a landmark?
The tunnel sits at mile 155.2 and measures 3,118 feet, or about 0.6 miles (3,118 divided by 5,280 is roughly 0.59). According to the NPS, it is lined with an estimated 6 million bricks.
Construction began in 1836 on a plan that called for two years of work. It took 14 years, and the tunnel opened in October 1850, the park service says. That is a useful reminder of how ambitious the canal was: the schedule slipped by 12 years on this one structure alone.
The tunnel let the canal cut straight through a ridge rather than follow the river’s bends, which is why it remains the route’s best-known engineering feature.
What should you bring and do inside?
The NPS says to bring a flashlight. Its page does not say whether the tunnel has interior lighting, so plan for darkness. Bike riders must dismount inside the tunnel and on boardwalks, and horses are not allowed.
The agency suggests parking at the Paw Paw Tunnel Campground, which sits at mile 156.1, and walking about half a mile to the tunnel. In winter, staff board up the south portal with plywood to protect the brickwork from wind and freeze-thaw damage; the tunnel stays open through a doorway in the boards.
Is there a way around the tunnel?
Yes. The two-mile Tunnel Hill Trail goes over the mountain and connects to the towpath at both ends of the tunnel. The NPS describes it as “steep and strenuous,” and bikers must dismount. It is a detour for those who cannot or prefer not to walk through the tunnel, not an easy shortcut.
How long did the canal work, and what happened to it?
The canal’s commercial era ended in 1924, according to the NPS, and the federal government acquired it in 1938. The gap between those two dates is 14 years. The agency’s history page describes the canal’s busiest period as “a little less than one hundred years.”
For readers, the practical result is that the towpath is now a recreation corridor rather than a freight route. The park today is visited for walking, biking, camping and river access, and some of its older structures, such as the tunnel, are managed as historic landmarks.
Can you camp along the towpath?
Yes, in several ways. The NPS lists stays in nearby canal towns, reserved campgrounds and hiker-biker campsites.
Hiker-biker sites
According to the NPS, these sites are free, first-come, first-served and cannot be reserved. The limit is one night per site per trip. Most are about 1 to 5 miles from the nearest parking area, with Swains Lock at mile 16.6 the exception. Each has a chemical toilet, picnic table, firepit and non-potable well water that must be filtered, chemically treated or boiled. Capacity is five to ten tents, depending on the site.
Drive-in and group sites
Drive-in campgrounds must be reserved through Recreation.gov and cost $20 per site per night, according to the NPS. Sites hold up to eight people and two tents. Stays are limited to 14 days between May 1 and October 1, and 30 days in a calendar year. There are no RV hookups, and trailers may not exceed 20 feet.
Group campgrounds cost $40 per night in peak season and $20 in off-peak season. Groups of more than eight people must use group sites or reserve multiple sites.
Timing matters in November
The NPS says water is turned off from mid-November to mid-April, so campers should bring their own backup supply. That makes this week and the next few a last window for relying on well water at campsites.
What are the rules at camp?
The NPS lists these rules, among others:
- Camp only in designated sites and carry out all trash.
- Quiet hours run from 10 p.m. to 6 a.m.
- Pets must be leashed.
- Bring only kiln-fired or dried firewood; do not tie ropes to trees or structures.
- Build fires only in provided fire rings or on raised portable grills, and remove extinguished coals from the park.
- Do not wash dishes, bathe or clean fish near wells.
Overnight parking at designated areas is allowed without a permit, the agency says, but it does not patrol lots regularly and parking is at the visitor’s own risk. In the District of Columbia and Montgomery County sections, visitors are asked to send their license plate number, a car description and an expected return date to the park’s permits office.
How much does it cost to visit?
The park is mostly free to enter. According to the NPS fee page, as of November 4, 2026, entrance fees apply in the Great Falls area and are collected at the entrance station. The page says it does not accept cash.
| Pass type | Fee |
|---|---|
| Private vehicle | $20 |
| Motorcycle (valid 7 days) | $15 |
| Per person on foot or bicycle (age 16+) | $10 |
| Non-commercial group (16+ persons) | $100 |
| Annual Entrance Pass (Great Falls area) | $35, valid one full year from the month of purchase |
Worked example: four friends on foot
Illustrative arithmetic: four adults walking in at $10 each would pay $40 for the day. The Annual Entrance Pass admits the pass holder plus three adults if entering on foot or by bicycle, according to the NPS, so one $35 pass would cover all four, $5 less than the per-person total. The pass also covers Great Falls Park in Virginia. Pricing can change, so confirm on the park’s fee page.
Is a full-length trip realistic?
Many cyclists do it. The NPS’s Mile 0 page says some start in Pittsburgh, ride the Great Allegheny Passage to Cumberland, then follow the towpath to Washington, for a total of 333 miles. Subtracting the 184.5-mile towpath leaves about 148.5 miles on the Great Allegheny Passage, illustrative arithmetic based on those two NPS figures.
The Mile 0 page, last updated August 15, 2026, calls the marker a spot where hikers and bikers can say they have “ended or are just starting” their full trip. Before heading out, the NPS recommends reviewing closures, current conditions, weather forecasts and safety tips; river and towpath conditions are posted on the park’s current-conditions page.
Where to go next in Maryland’s outdoors
The canal fits neatly with other seasonal outings. If you are chasing color, see our report on Maryland fall foliage conditions. For another slow-paced outdoor trip, read the Assateague wild horses viewing guide, or browse Maryland’s state symbols for more on what makes the state distinctive.
A long path with a short checklist
The towpath rewards preparation more than athleticism: carry a flashlight for the tunnel, treat well water, reserve drive-in sites ahead, and remember that campsite water goes off in mid-November. With the right gear, a stretch of the 184.5 miles can be a single afternoon or a multi-day trip.
This article is general information based on National Park Service pages. Conditions, fees and closures change, so check the park’s current notices before traveling.
Sources: National Park Service
