Every morning for two years, Alexandria resident Henley Fant, a vice president of the Road Runners Club of America, passed a bearded and helmeted cyclist on the Mount Vernon Trail with whom she exchanged a wave and a smile, as she did with everyone. Fant would be returning home from her nine-mile run. The cyclist would be on his way to work.

"We would always be passing going the opposite direction," she recalled.

One morning after an injury forced her to change her running pattern, the jogging Fant heard the squeaking brakes of a bike behind her. It was the bearded cyclist.

"This particular morning, I was going the same direction he was for the first time in three years," Fant said.

So after exchanging names and dating steadily for four years, Henley Fant, 41, married cyclist Jim Gibble, 42, who works as a civilian engineer in aircraft safety for the Navy. "I really have a fondness for the trail, mainly for that reason," she said.

While not everyone is going to find love on the trail, hundreds of thousands of Washington area residents have made the 17-mile trip from Arlington Memorial Bridge to Mount Vernon one of the biggest social and recreation scenes in the area.

On any warm weekend, the 13-year-old trail is a riverside ribbon streaming with cyclists, roller skaters, runners, joggers, brisk walkers, and even young mothers pushing baby carriages. They come to exercise, to view the river, to let nature work its cure on work-battered minds and bodies or to meet those with similar interests.

On a recent Sunday, cyclists lounged in a great circular island of grass at the entrance gate to Mount Vernon. Although it was just past noon, some had already finished and were ready to make a return trip after paying homage to the sun.

Ed Borawski, 64, had driven from Indian Head in Maryland's Charles County, parked his car in West Potomac Park near the Lincoln Memorial and biked the whole trail. In good weather, Borawski, who works for the Naval Medical Command in the Pentagon, rides the 34-mile round trip every weekend.

Intrepid trail roller skater Jenni Bryant, 25, recently moved from Ohio to Virginia where she works at the Beech Aircraft Corp. in Rosslyn. Her knee bandages testify that the Mount Vernon Trail is not without the hazards of "ditching." But weekend after weekend, Bryant skates seven miles. Eventually she hopes to reach the 14-mile mark.

Also riding bikes and walking the trail on a recent Sunday were participants in the Juvenile Diabetes Foundation's "Walk, Ride and Roll" benefit. Jim Kozelsky, 43, with his two children Susan, 14, and Keith, 11, of Burke had ridden seven miles from the Belle Haven Marina on the trail south of Alexandria to raise $150 between them to help the foundation. Seven miles is seven miles, however, and they were waiting for Mrs. Kozelsky and the family station wagon to carry them, bikes and all, back to Burke.

In January the National Park Service opened a $2.75 million marina restaurant called Potowmack Landing, alongside the trail on Daingerfield Island about two miles north of Old Town. Attached to the restaurant is a bicycle shop. A group of weekend sailors, who are weekday nurses at Georgetown University Hospital, were on the restaurant's outdoor deck on a recent Sunday proclaiming the virtues of the life out-of-doors as they shared a pitcher of beer. "This is the only place I know between here and Old Town. Don't tell too many people about it. We don't want it to be overcrowded." -- Kate Dolan

"There aren't enough outdoorsy places in Washington," said Mary Margaret Estill, 25.

Her coworker, Kate Dolan, 25, who lives in the District, agreed. "This is the only place I know between here and Old Town," Dolan said. "Don't tell too many people about it. We don't want it to be overcrowded."

Creighton Smith and two friends were also taking a break at Potowmack Landing. Smith rides the trail round trip from Crystal City to Mount Vernon twice a week. His friend Jack McGlew, a law student at American University who has been riding the trail about a year, had just made his first 30-mile round trip. "It's not that hard," he said.

Friend Marianne Dischleit, on one of her first times out, had put in just two to three miles that day. All three said that the new bar and restaurant were sure to increase the social aspects of using the trail.

A stone's throw from the restaurant, Bill Massey, 30, and his wife Kathy, 27, of the District, lay in the sun after riding along one part of the Mount Vernon Trail. Massey concedes that this trail is "probably the best around," but the day that the District public pools open up, their loyalties will shift. "Swimming is better than biking," said Massey.

But there are die-hard enthusiasts who cycle the trail twice a day, rain or shine: the commuters.

"Oh yeah, I bike all year round," said Ray Blunt, 42, who rides from Stratford Landing in southern Fairfax County to his job at the Veterans Administration in the District, a total of 15 miles, which takes him a little over an hour.

"I've gotten caught in a snowstorm. That's about the only thing that will stop me. I took it slow; it was a little hairy," Blunt said.

During the shorter days of winter, Blunt said that his bike needs a special lighting system to make sure that he can see and be seen along the trail.

The best part for Blunt, however, is observing nature. Every day he passes through heavily wooded areas of tulip and beech trees and Dyke Marsh as well. "I love to watch the change of seasons. The light is different, the temperature is different, every day is just a little bit different," Blunt said.