It came from above and mimicked the sound of a far away jet engine, but there was no jet in sight, just a circle of geese fast approaching the earth.

Matt Charros and his four-legged companion hadn't heard anything like it but soon realized they were likely the only ones to have experienced such a sound while crossing over the Utah border in a barren part of the state sometime last week.

"There is not a whole lot out there," Charros said. "It's nice and quiet."

Charros, 38, and his dog, Onyx, are trying to make a statement with their feet, walking more than 3,400 miles to raise funds to start an art therapy studio for people suffering from multiple sclerosis and for veterans with post-traumatic stress disorder.

His "walk of a lifetime" began on Easter Sunday in West Quoddy Head, Maine, the easternmost point of the United States. Charros arrived in Salt Lake City Thursday, visiting friends at Westminster College, his alma mater. He plans to make it back to his hometown in Massachusetts by the end of November, after planting his feet on the coast of California, making his journey complete.

"The biggest challenge so far has been the altitude," he said. "Eight thousand feet is tough and you have to make small strides. The Midwest was kind of boring, mentally, and it starts to wear on you. I was not a big fan of Iowa; I thought the Midwest was supposed to be flat but it wasn't. However, when I hit the Rockies, it was a rejuvenation."

"I can really haul," he said. Charros walks up to 30 miles each day, moving at a pace of about 3.5 mph. For the most part, he said, he stays off the beaten path and out of the way, sleeping in a tent alongside roads and in forested areas, but occasionally drivers stop to ask questions or honk at him to get out of the way. His dog is a gentle and friendly traveling companion, but "he doesn't like diesel engines or the UPS man," Charros said.

He's been through some monsoonal rain showers, windstorms and other treacherous weather conditions, but he has kept walking all the while, hoping to beat the winter storms. He pushes a 150-pound baby stroller holding all his gear, which has required tire replacements a number of times, and he's worn out four pairs of shoes.

He had an iPod, but it got wet and malfunctioned. He said he likes just taking in the landscape. Had he been listening to music while crossing into Utah, he said he'd have missed out on the unique sound of birds in flight.

Charros is not completely removed from modern conveniences, as he charges his laptop and cell phone with a portable, foldable solar panel. However, he eats dehydrated food and takes shelter under a huge tarp when it's dark or rainy.