Using his trusty BB gun to help him return to Earth, a 48-year-old American service station owner flew a lawn chair rigged with helium-filled balloons more than 322 kilometres across the Oregon desert, landing in a field in Idaho.

Kent Couch created a sensation in the tiny farming community of Cambridge, Idaho, where he touched down safely in a paddock and was soon greeted by dozens of people who gave him drinks of water, local plumber Mark Hetz said.

"My wife works at the City Market," Hetz said. "She called and said, 'The balloon guy in the lawn chair just flew by the market.'

"We go outside to look, and lo and behold, there he is. He's flying by probably 100 to 200 feet (30 to 60 metres) off the ground.

"He takes his BB gun and shoots some balloons to lower himself to the ground. When he hit the ground he released all the little tiny balloons. People were racing down the road with cameras. They were all talking and laughing."

Couch covered about 235 miles (378 kilometres) in about nine hours after lifting off at dawn from his petrol station riding in a green lawn chair rigged with an array of more than 150 giant party balloons.

Couch had kissed his wife and kids goodbye as he prepared to leave, and patted their shivering Chihuahua, Isabella, before his ground crew gave him a push so he could clear surrounding light poles and a coffee cart.

Then, clutching a big mug of coffee, he rose out of the parking lot of his petrol station into the bright blue morning sky, cheered by a crowd of spectators.

"If I had the time and money and people, I'd do this every weekend," Couch said before getting into the chair. "Things just look different from up there. You've moving so slowly. The best thing is the peace, the serenity.

"He's crazy," said his wife, Susan. "It's never been a dull moment since I married him."

Each balloon gives 1.8 kg of lift. The chair was about 181 kg, and Couch and his parachute 90 kg more.

It was his third flight. In 2006, he had to parachute out after popping too many balloons. And last year he flew 310 km to the sagebrush of north-eastern Oregon, short of his goal.

Couch was inspired by a TV show about the 1982 lawn chair flight over Los Angeles by truck driver Larry Walters, who gained folk hero fame but was fined $US1,500 ($A1,563) for violating air traffic rules.

‘Dream big’

Dozens of volunteers wearing fluorescent green T-shirts with the slogan, Dream Big, filled Couch's 1.5-metre-diameter latex balloons and fastened them to the rig carrying his chair, before he left. A few balloons popped, and one got away.

"I think it's wonderful he's got guts enough to do it," said retired commercial pilot Bob Banta. "I've owned 12 little airplanes, but I've never done anything like this."

Couch, a veteran of hang gliding and sky diving, estimated the rig cost about $US6,000 ($A6,250), mostly for helium. Costs were defrayed by corporate sponsors.