HALLOWELL – Scott Cowger is among just five people who can say they have biked in every Trek Across Maine, the annual American Lung Association fundraiser that begins today for the 27th year.

It’s a feat he plans to talk about often during the 170-mile bicycle ride from Bethel to Belfast, with the cyclists — they call each other trekkers — sharing countless stories over the whir of tires on pavement.

“One of the most common questions is, ‘How many years did you ride?’” said Cowger, 51, of Hallowell, in a phone interview.

When they find the veteran trekker, less experienced riders will ask for secrets he has learned by biking across central Maine each year for more than a quarter-century. “I guess I’m a novelty more than anything,” he said.

Cowger, a co-owner of an inn and conference center, said other trekkers are amazed by stories about how the fundraiser has grown over the years.

“They used to hand us a map and say, ‘Here you go.’ There may have been some water (stops) along the way, but pretty much you were on your own to make it to the end,” said Cowger, recalling his first trek.

A popped tire left him stranded for an hour in the rain during that first ride, which had precious few support volunteers and mechanics.

“A big piece of glass cut a hole in my tire and I couldn’t fix it myself, so I had to wait for the one mechanic on the road, as opposed to the teams of mechanics they have along the way nowadays,” Cowger said.

Riders had a tough time finding the route in the early years, especially if they got separated from the pack. “I rode on, not really seeing anybody ahead of or behind me, not knowing if I was headed in the right direction,” he said, because of a lack of signs.

The trek has grown steadily and become a small community on wheels, making its way toward the coast over three days, stopping overnight at the University of Maine at Farmington and Colby College in Waterville.

This year there are more than 2,300 cyclists, being helped by about 650 volunteers. That’s a big jump from fewer than 400 riders and a handful of support-staff volunteers when the event began.

Cowger calls it a mix between an adventure and a reunion. “You make friends on this trip; you ride along together and talk politics and catch up from the past years,” he said.

Trekkers don’t forget that they are raising money for the American Lung Association, said Cowger, who was a Maine legislator from 1996-2006.

The trek has raised $16 million in its 27 years. There are 150 teams raising money this year, drawing cyclists from 28 states, organizers say.