By Ben Klayman

DETROIT (Reuters) - Barclay Oudersluys had competed in triathlons and ultramarathons but he wanted to do something bigger, so the Michigan native took a cue from his favorite movie.

Inspired by Forrest Gump, the simple but well-intentioned man played by actor Tom Hanks in the 1994 Academy Award-winning movie of the same name, Oudersluys decided to run across America and set out to do it in 100 days.

"I decided if Forrest Gump could run across the country, I could do it too," he said in a telephone interview this week after he had completed his 61st day of running in Mount Pulaski, Illinois.

Rising every morning around 6 a.m., the 23-year-old from Birmingham, Michigan, has kept a daily pace of 30 to 33 miles(48 to 53 km), a distance greater than a marathon. Like Gump, he is running from the Santa Monica Pier in California to the Marshall Point Lighthouse in Port Clyde, Maine, a route already taken by an undocumented number of runners.

Oudersluys' plan, dubbed Project Gump, will take him through 14 states and over about 3,150 miles (5,070 km), ending on Aug. 16, shortly before the University of Michigan graduate with bachelor's and master's degrees in nuclear engineering starts law school at the University of California, Berkeley.

In the movie, Gump's repeated cross-country jogs inspire people to join him. Oudersluys is in turn trying to raise $10,000 for the Hall Steps Foundation, a charity started in 2009 by two professional distance runners to fight global poverty. About halfway to his goal, Oudersluys plans to donate the money to help build a well in Mozambique.

While many on his Facebook, Twitter and Instagram accounts documenting the run laud him, some question whether he can finish the run without his body breaking down.

Dr. Paul Thompson, a sports medicine specialist and chief of cardiology at Hartford Hospital in Connecticut, said Oudersluys is racing into the unknown.

"From a medical point of view, we don't really have that much knowledge about what that can do because there aren't that many people that do that sort of thing," he said.

Since this isn't a race, Oudersluys' pace can be slower, allowing for less damage to the muscles and less stress on the heart, Dr. Thompson said.

While friends have helped in some stretches, driving his white 2003 Dodge Caravan minivan, Oudersluys at times has had to act as his own support. On those days, he leaves his bicycle at the starting point, drives to his end point, runs back to the bike and then bikes back to the car before resting for the day.

Oudersluys sometimes stays with friends, but most of the time he sleeps in his van, using a small stove to cook.

Strange sights on his trip so far include a lonely shoe-draped tree in the Mojave Desert and zebras on a Colorado farm.

After beginning his journey on May 9, Oudersluys, 5-foot-9 (175 cm) and he guesses 10 pounds (4.5 kg) lighter than his starting weight of 165 pounds (75 kg), has had few companions other than those with four legs.

"I've had a lot of dogs come run with me," he said. "Most stay for like five or 10 miles (8 or 16 km). I don't know how they end up getting home."

(Editing by Eric Walsh)