The 23-year-old from Ann Arbor, Mich., has hiked and camped through Europe, Australia, New Zealand and India. He has traversed part of the Appalachian Trail, through Tennessee and the Carolinas.

Now he is about to embark on his biggest adventure—taking on the 6,300-mile American Discovery Trail with his horse, Smokey.

The trail is the only nationwide trail of its kind. It's a connection of trails that stretch from California to Delaware, and it's meant for hikers, cyclists and equestrians only. No motorized vehicles are allowed. Parker thinks he is the first to make the trek along the trail entirely on horseback.

He's doing it simply because he "figured it would be something very epic to do, something that few would want to do and even fewer could accomplish."

The nationwide trail, which runs through cities, townships, forests, mountains and deserts, connects five national "scenic" trails, 10 historic and 23 national recreational trails. It leads to 14 national parks and 16 national forests.

Graphic courtesy of the American Discovery Trail Coast to Coast: This map shows the 6,300-mile American Discovery Trail.

The trail is funded through corporations and promotions from the hiking and trail societies, along with the local municipalities through which the trail runs.

Parker had been staying with his brother, Christian, for only a few months when he got the itch to travel again.

Parker knew he wanted to cross the country, and when he learned of the American Discovery Trail, he got the idea to travel it on horseback.

"The horse was secondary to the idea," he says.

He'd always wanted to traverse the country, and he played with the idea of doing it on horseback "because it was something that's infrequently done and the challenge of taking care of a large animal makes it an exponential challenge."

But not everyone took the idea as seriously as he did.

"A friend recommended I ride a camel, but that just doesn't have the same allure," he jokes. "Although I guarantee I would be the first person to cross the country on a camel."

His horse, a 6-year-old Tennessee walking horse named Smokey, is probably not too bothered by what lies ahead. He was born for this kind of stuff—literally.

A Tennessee walking horse has long, sloping shoulders and hips and short hair, which provides for longer strides and little wind resistance. The breed was popular among plantation owners in the South because overseers could ride them comfortably for hours due to the horse's easy, ambling gait.

Parker bought Smokey for $2,200 and had him shipped from Tennessee about 2¹/2 months ago.

Parker, while an experienced camper and hiker, didn't have much experience with horses. When he got the idea to travel the American Discovery Trail, he began taking horseback riding lessons and learned how to care for a horse.

On his first day of training he met Rhonda Heiner, a prominent horse trainer from Washington state who now lives and trains in Morgan Hill.

He was waiting for another trainer when Heiner struck up a conversation with him and learned his ultimate goal was to ride cross country on horseback.

Heiner, an accomplished competitive trail rider in Washington who would ride up to 150 miles a day, decided to train Parker in how to ride and care for a horse.

"I put him and Smokey through a crash course and showed him how to negotiate hills and awkward terrain," she says, "I've tried to familiarize him with conditioning and how fast his horse can go or how many hours he can go in an hour and make him aware that he won't be able to go a hundred miles a day."

Photograph by Jacqueline Ramseyer Leg Stretching: Matt Parker and his horse, Smokey, exercise at a riding stable in Morgan Hill. The pair will leave to tackle the 6,300-mile American Discovery Trail the last week of May. The journey will take a year.

"I'm not willing to sacrifice the life of my horse," he says. "I mean, if something happened to me—like a broken arm or whatever—I could deal with it. But for Smokey, if he goes lame it's usually a pretty big deal."

The possibility that Smokey could be injured somewhere along the way brings a cold sobriety to Parker's voice. "If a horse breaks a leg, then you have to kill him."

He's never put a horse down and hopes he'll never have to.

To keep things simple for himself and easier for Smokey, Parker will use lightweight bags and minimal camping equipment.

"All five of the nylon bags I'll be carrying together weigh less than one leather saddlebag," he says.

Parker's preparing for everything, but he says his family has always been there to support him in anything he does, no matter how ambitious. And this latest adventure doesn't surprise his family, he says.

His brother, a sales executive with the San Jose Sharks, supports Parker.

"He is a loving brother and he realizes this is something I like to do," Parker says. "It's something he would never do, but he respects it. Traveling has always been the only thing I ever cared about."

And just as earlier adventures prepared him for crossing the discovery trail, this adventure should prepare him for others.

Once completed, he plans to join the Peace Corps. His preference would be returning to India or going someplace new in Africa.

"I figured if I could do this, then I could do that," he says. "I think this will teach me a lot. But I would not have attempted riding the trail had I not had extensive experience camping and hiking."

Yet the great outdoors alone isn't what keeps his life interesting.

"I've always felt I was living the most when I was putting myself in mortal danger," he says.

Parker recalls being part of an entourage in India.

"We would count all the times we were in jeopardy every day," he says. "We were in danger of everything: disease, flood from monsoons, horrible drivers, bad living conditions, I mean, you name it, man. There's nothing normal about that place. But it's very beautiful."

Parker also casually recalls an ordeal last year while hiking the Appalachian Trail, where he was tracked for two days by a mountain lion.

"That wasn't too fun," he says nonchalantly.

"You know how the hairs on the back of your neck stand up? You know you're being watched when you find tracks at night. Mountain lions are very inquisitive, and you don't want something that large and inquisitive around you."

He was able to avoid the lion, as well as survive treks through other hostile terrain because of a combination of luck and skill.

"Sometimes it's just luck that nothing bothers you; sometimes it's skill to survive when something does bother you, and sometimes it's just damn bad luck and you get bothered and you can't do much about it."

He doesn't consciously seek out risky situations, however.

"I go to a place that interests me and at times I just happen to find myself in danger."

Camping and hiking in isolated areas far from civilization can put an individual in harm's way, Parker notes.

"If you hurt yourself or something else goes wrong, you rely on your own intuition and skills. And that is a very satisfying feeling if you saved yourself or just had a great time going through a treacherous area," he says. "It's much more rewarding than completing a day at work doing menial things."

Although he was in California a short time and only worked in the kitchen at Trials Pub on N. First Street in San Jose for a few months, the owner, Greg Mast, held a fundraiser one night for him the week before he left.

"You don't need to know someone for a long time to know they're a good person," Mast says.

And to help make the most of the event, he scheduled the fundraiser on a Friday, the pub's busiest night. Parker's pub co-worker Renée La Barge arranged for one dollar from each drink or entrée sold to go toward Parker's expedition fund. About $375 was raised for him and Smokey.

"It's just great. I went from a boring job to a new job at Trials, and they really took to the idea of my leaving on this trip," he says.

He adds, "Everything has worked out. I can't stress enough how surreal the whole thing has been, but the last two months things have really begun to come together."

His other globe-trotting jaunts were funded "very shrewdly," he says with a sly laugh. His grandfather was his benefactor for several years, but Parker has worked and saved for his adventures.

For this trip, he arranged for some trail coordinators to accommodate him every few miles so he can rest and shower.

Parker could have also sought out sponsors but thought better of it.

"I thought sponsorships would be really cool if I started running out of money," he says, "but I don't think it's worth it. Once I get involved with sponsors there'd be any number of hoops I'd need to jump through, and I really didn't want to sacrifice the integrity of the trail. It's just my purist nature, I think.

"Of course, I want people to know I'm doing something that's going to be tough and great, but when I'm done and no one cares, then so be it."

He leaves just before the last week of May. He'll cross Nevada and Utah and take the northern route where the trail divides in Boulder, Colo. He'll break off the trail and ride north to spend the winter at home in Michigan. He'll get back on the trail to make it to his childhood home of New Haven, Conn.—where he lived until age 10—by this time next year.

"I thought it would be really great if I could end the trip at the front doorstep of my old house from when I was a little kid," he says.

For more information about the American Discovery Trail, write the American Discovery Trail Society at P.O. Box 20155, Washington, D.C. 20041-2155, call 800.663.2387 or 703.753.0149, or visit www.discoverytrail.org.