PORTLAND — The man who started annual bicycle treks across Maine has pedaled his way to a bigger job.

Peter King is organizing the American Lung Association’s trek across America, also known as the Big Ride, with a fund-raising goal of $4.5 million.

King organized the first 180-mile Trek Across Maine 14 years ago. Since then, participation in the three-day trip has grown from barely 100 riders to 1,400 this year.

The American Lung Association says King, 45, has shown he’s the best man to head the six-week Big Ride. About 500 people will pedal 3,250 miles from Seattle to Washington, D.C., next summer.

Working from his office in Portland, King heads a staff of four that will coordinate meals, campsites, showers and other services for the nation’s biggest cross-country bicycle ride.

“He has the skills both to conduct the ride and to generate enthusiasm for it among the lung association’s chapters throughout the country,” said Edward Miller, executive director of the American Lung Association of Maine.

King, an avid cyclist, came to the Maine lung association in 1984 after working for several years in New Hampshire as an elementary school teacher and as education coordinator for the lung association’s New Hampshire chapter.

His proposal for a fund-raiser that appeals to people’s sense of adventure and their desire to help a good cause gave birth to the Trek Across Maine.

In 1985, the event raised about $50,000. This year it brought in $750,000, two-thirds of the Maine chapter’s yearly budget.

“Peter has done an exceptional job,” said Robert Verrill, who worked with King on the Maine ride for nine years. “He thinks creatively and is always open to other people’s ideas. Now people call us from all over the country to ask about how to put on a ride.”

Winnie Jones, who has made 11 Treks Across Maine and last year’s Big Ride, is helping to organize the next ride across the country.

Jones calls last year’s Big Ride one of the best experiences of her life. She rode about 80 miles a day, often through wind, snow, rain and baking heat.

“The sense of camaraderie is pretty powerful,” Jones said. “Sometimes it becomes almost a spiritual experience.”