The 127-year-old C & O Canal and its towpath will be dedicated to retired Supreme Court Justice William O. Douglas May 17, with the unveiling of a bronze bust in Georgetown, beside the historic and scenic canal he helped preserve.

Douglas, who hiked the entire 185-mile canal with journalists and conservationists in 1954 after plans were announced to turn it into a highway, was instrumental in preservation of the waterway and the ultimate creation of the C & O Canal National Historical Park in 1971.

The retired justice, confined to a wheelchair and partly paralyzed since suffering a stroke in December, 1974, is expected to make a rare public appearance to attend the 2 p.m. ceremony. He was hospitalized for almost two months last fall after breaking his hip in a fall at his home here. Douglas retired from the court in November, 1975.

The National Park Service, in its master plan for the canal park released last year, gives Douglas "much of the credit" for saving the canal and adds "it has been said this is the first National Park ever walked into existence."

Douglas challenged editors of The Washington Post, which had previously endorsed plans to build a parkway along the canal, to make the 185-mile hike with him and other conservationists in 1954. In a letter published in the paper, Douglas described the canal and its stone aqueducts, tunnels, locks and magnificent scenery "not yet marred by the roar of wheels and the sound of horns," and urged editors to see for themselves that "the stretch of 185 miles of country from Washington to Cumberland, Maryland is one of the most fascinating and picturesque in the nation."

After accompanying Douglas and others on the hike - nine persons completed the entire 185-mile march - the paper reversed its position on the canal highway. The federal government later dropped the road plan, and 14 years of efforts began to guarantee the canal's preservation by making it one of the nation's 300 national parks. The efforts were launched on the last night of the hike, in March, 1954, when Douglas organized a committee to work for the canal's preservation and expansion - the committee evolved into the C & O Canal Association, its unofficial guardian. President Eisenhower proclaimed part of the canal a national monument in 1961, and bills to make it a national historical park were considered by Congress from 1957 until enactment in 1971.

A commemorative hike along the canal was held last weekend, as it has every year since 1954, to honor the efforts of Justice Douglas and others in preserving the canal. This year 325 persons hiked the 12 miles from White's Ferry to Point of Rocks.

Although the canal park has been expanded from some 5,000 acres to more than 20,000, it also has suffered some reverses, more than $45 million worth caused by tropical storm Agnes in June, 1972, which destroyed major sections of the canal and damaged the rest.

While former Interior Secretary Rogers C.B. Morton pledged to have the canal completely restored by the Bicentennial, only about $6 million in stablizing work has been done so far. Another $1.8 million is being requested by the Park Service for fiscal 1978, but Congress has yet to approve the budget. The canal tow path is still not passable in some sections, and hikers and bikers must make detours of up to 7 miles to skirt the closed sections.

The 175-pound bronze bust of Douglas, to be mounted on a 5-foot granite pedestal where the canal passes under 30th Street in Georgetown, was sculpted by Park Service recreation specialist and artist Wendy Ross, who works at Glen Echo Park and made the bust on her own time as a tribute to Douglas.