The mules at Great Falls wore yellow rainsheets. Most hikers wore ponchos, parkas, slickers and other supposedly waterproof outfits. But chilly rain and soggy socks barely dampened the spirits of two groups that hiked the C & O Canal on Saturday.

About 240 people tramped 12 miles from Seneca to Carderock on the C & O Canal Association's 26th annual reunion hike.

A smaller group also slogged toward Harper's Ferry on the local Sierra Club's eighth annual 100-kilometer hike. Of the 95 who set out from Washington at 3 a.m., 27 completed the muddy marathon trek around nightfall.

Although the towpath got slick and three pairs of socks were required, "this was the easiest of the five times I've done it," said Joe Greene of Silver Spring, an organizer of the march.

"You just had to keep going," said Sue McElfresh of Springfield, who had trained hard for the hike and finished "four hours ahead of last year" without any blisters.

The chilly rain did cause problems for some. Jim Finucane of Washington, an experienced long-distance runner, was "ill-dressed" in a windbreaker, t-shirt and shorts, and got "uncomfortably chilled." As did a number of others, he stopped at White's Ferry after trudging about 37 miles.

"I learned there's a real difference between running 26 miles and walking 62," Finucane said. For all but the most dedicated hikers, he concluded, the canal association's more casual jaunt "may be a better idea than ours."

The 12-mile hike was dedicated to the late Supreme Court Justice William O. Douglas, whose now-lengendary march in 1954 sparked the long fight to save the old canal as a national park. This year's reunion was led by Cathy Douglas, the justice's widow, and included his favorite Pennyfield section of the 184.5 mile trail.

The rain did have an impact on this annual rite of spring. There were more umbrellas than children, no bicyclists and only two or three dogs, including one small, basically white terrier that grew more mud-colored by the mile. Some hikers maintained a determined pace, with far more lingering at the coffee stops than along the trail.

The dampness did intesify the fresh green of the woods, the glints of wild flowers and the hues of redbud and dogwood against the west black of the 500-million-year-old cliffs along the route. But the rain deterred most would-be photographers. The birdwatchers were also disappointed because most of the birds stayed home.

John McAdams of Annandale did report spotting muskrat and deer tracks on the towpath, along with those of dogs, horses, bicycles and several species of sneakers, before a mid-morning downpour turned all the prints into mud.

William E. Davies of Falls Church, one of the most irrepressible amblers in the group, counted the rings on several large stumps and found some dating back to the Civil War era when much of that section of the canal had been rebuilt. t

Because of the rain, few local politicians made the brief appearances that have become standard at sunnier hikes. The day's most vigorous campaigning was done by representatives of area Girl Scouts who are fighting to save Rockwood, a 96-acre nature center near Great Falls that the Scout's national organization is trying to sell to a housing developer.

The Scout's best lobbying was done by senior troop 1120 from Vienna and Oakton, which provided large sandwiches and hot beverages for lunch at Great Falls.

While few dignitaries dropped in, relatively few hikers dropped out.

"Once you start you might as well keep going," Ruth Bronstein of Wheaton explained. Others described the rain as a minor complication of the major social event that the "Douglas hike" has become.

Douglas' leadership was the major theme of the association's annual banquet at St. Francis Episcopal Church in Potomac that night. The adience of about 150, including many in muddy shoes, heard brief remarks by Rep. Michael Barnes (D-Md.) and Cathy Douglas, and saw a new 14-minute film on the 1954 hike produced for the National Park Service by local filmmakers Tina Manatos and Helene Jennings.

The day's most fitting reminiscence was provided by Bill Davies, who recounted the now-legendary tale of the 1961 hike when Douglas, then-Interior Secretary Stewart Udall and others got caught in a downpour, sought refuge at Angler's Inn and were turned away because they were too muddy.

"The manager said, 'You're Democrats, I'm a Republican and I don't give a damn how wet you are, you can't come in.' Now the inn has different management and we might stand a chance," Davies said.

At the inn that afternoon, waiter Jim Guzel said that no wet hikers had stopped by. Asked whether they would be admitted if they came, he glanced at the restaurant's spotless carpet and responded, "It would depend on how grubby they are."