A long stretch of history ... and recreation. (Great parks: the Chesapeake & Ohio Canal National Historical Park).

The Chesapeake & Ohio Canal National Historical Park must be one of the oddest-shaped parks in the country. Running 184.5 miles from Cumberland, Md., to Washington, D.C., in some places it's no more than several feet wide. Its thread-like shape notwithstanding, for more than three decades it's been among the most popular recreation sites in the Washington, D.C. area.

The park gets its shape, of course, from the canal's original purpose as a shipping route. The C&O Canal was just one of the dozens of canals built on the East Coast during the first half of the 19th century. Teams of mules, averaging just 2 miles per hour along the canal's towpath, pulled barges designed especially for traversing the shallow canal and filled with coal and other commodities. Seventy-four locks, 11 aqueducts and other engineering feats allowed smooth passage from the mountains of Western Maryland to the flatlands. (The canal drops 600 feet from Cumberland to its other end.)

Unhappy History

The canal as a commercial enterprise was doomed from the start. The idea seemed solid--create an overland route linking the Eastern seaboard, via the Potomac River, with what was then the West, the Ohio Valley country--but logistics proved nettlesome. A survey in the early 1820s put the cost at $22 million, and there were endless squabbles about who should pay what, where the canal should start and other non-insignificant details.

Work began on July 4, 1828, on a 350-mile route that would go from Washington to Cumberland, then on to Pittsburgh, Pa. President John Quincy Adams gave a speech and grabbed a spade to ceremoniously mark the groundbreaking. He struck a root, and had to make two more attempts. On the same day, ground was broken 40 miles away in Baltimore, Md., for the B&O Railroad. By the time the canal reached Cumberland in 1850, years behind schedule and millions over budget, the railroad, which paralleled the towpath in many places, had largely doomed it to commercial irrelevance. (Trains, after all, tend to go faster than boats pulled by mules.) The second segment, from Cumberland to Pittsburgh, was quietly forgotten. After a brief profitable spell following the Civil War, the canal slid into increasing debt. Its caretakers closed it for good in 1924 after yet another flood did too-costly damage to its infrastructure.

After the flood ended commercial activity on the canal, its owner--by then, ironically, the same B&O Railroad that had helped to strangle it during the previous century--looked on with disapproval as talk of creating a highway along the route sprouted. The talk increased significantly when the federal government bought the canal from the railroad in 1938. By the early 1950s, the proposed roadway had morphed into a scenic parkway, an idea that The Washington Post endorsed in a 1954 editorial.

Supreme Court Justice William O. Douglas dissented. "I wish the man who wrote your editorial ... approving the parkway would take time off and come with me ... I feel that if your editor did, he would return a new man and use the power of your great editorial page to help keep this sanctuary untouched," he wrote to the Post in January 1954. Two months later, Douglas, two Post editors and 34 others set out to traverse the towpath in eight days. Only nine--including Douglas but no ink-stained wretches--completed the trek, but the hike brought enough good publicity that the Post changed its mind. The parkway scheme was quashed. In 1971, President Nixon made the canal a national historical park.

The Path to Recreation

According to the National Park Service, the park hosts millions of visitors each year. The 14-mile eastern end of the canal, from Great Falls to Georgetown and mere minutes from the densely populated Washington suburbs, is by far the most popular stretch. In My Wilderness: East to Katahdin, Justice Douglas eloquently explained why: "The din of the city, the roar of its traffic, was behind me ... The schemes and machinations of the little men who possess the place seemed far away. I did not have to go far ... to reach this wilderness of solitude and quiet. Only a few miles. That's what the cities need, I found myself saying. A wilderness at their back door, where a man can go and once more find harmony and peace in his inner being."

Most visitors take the most obvious recreation route--they hike or bike on the towpath. Most treks are short, although the beauty of the canal and the flatness of the towpath are often inducement to add on a few miles. The soft, flat surface of the towpath and its waist-high mile markers also make it one of the most popular running spots in the Washington area.

Some hikers and bikers want it all. Groups such as the C&O Canal Association regularly reenact Justice Douglas' through-hike of the towpath, while organizations such as the Washington Area Bicyclist Association organize length-of-the-towpath rides. For relatively fit riders, a three-day traversal of the towpath is standard. Two-and even one-day rides aren't unheard of. Others take as long as a week, allowing plenty of time for side excursions to the many historical sites along and near the canal. For example, an 18th century military outpost, Fort Frederick, is preserved not far from the 112-mile mark of the towpath. The Antietam battlefield, site of the bloodiest day of fighting in the Civil War, is just a few miles from the 72-mile mark. Harper's Ferry, W.Va., where John Brown failed in 1859 to ignite a slave uprising, is just across the Potomac River from the 60-mile mark.

The canal and parallel Potomac River allow many other types of recreation. Birdwatching is popular. The variety of environments along the 184 miles of the park--canal, river, timberland, marsh, swamp--attracts a wide range of species. Birdwatchers especially flock to the wildlife sanctuary found near the 20-mile mark and the wildlife management area near the 27-mile mark. With great blue herons frequent along the river's edge and bald eagles nesting in denuded trees, even those on the towpath for other reasons are likely to become birdwatchers.

Naturally, fishing in the Potomac River is an activity of choice. Most of the canal is unwatered, but the stretches that contain water also contain species such as catfish, carp and sunfish. These stretches also host human species, in the form of canoeists and kayakers, who also take to the Potomac.

Hikers, bikers and general outdoor enthusiasts make great use of the many campsites along the towpath. All but two allow unrestricted use. Spaced four to eight miles apart, and featuring toilets and water pumps, they're convenient stops for those who want to spend a night near the towpath.

Among other types of recreation are rock climbing at two sites near Washington, cross country skiing soon after a snowfall and horseback riding, which is allowed from Swains Lock, at the 16.7-mile mark, all the way to the terminus in Cumberland.

Teaching the History

The National Park Service maintains six visitor centers along the canal. Rangers lead tours describing the rich history and environmental landmarks of the surrounding areas. The visitor center at the terminus in Cumberland houses an interactive museum that chronicles economic life on the canal during its heyday, including a to-scale replica of a commercial canal boat.

Two of the visitor centers--Georgetown and Great Falls, both in the Washington area--offer mule-drawn canal boat rides. The hour-long rides go through an operational lift lock, and are guided by park rangers dressing in 1870s clothing. On weekends, Girl Scouts dressed in period clothing lead tours of Rileys Lockhouse, near the 22-mile mark, and demonstrate typical tasks of being a member of a lockkeeper's family.

As occurred during its commercial peak, the canal and towpath are easily ravaged by severe weather. Flooding after a 1996 blizzard quickly melted did extensive damage to stretches of the eastern towpath. Farther west, the towpath isn't traversable near Big Slackwater, a calm stretch of the Potomac in which canal boats were diverted for two miles. Too-frequent floods have eroded the towpath so much that through cyclists and hikers leave the canal area for a four-mile detour on roads. Recognizing this fragility, the National Park Service and nonprofit friends groups work diligently throughout the year to keep what Justice Douglas called a treasure available to all.