ASPEN - When Bryon Chambers stopped on a ledge halfway through the climb to catch his breath and plan his next move, everyone watching was unsure if he would continue.

But 10 minutes later, he was grinning at the top of the pitch.

"It kicked my butt, but if felt good and I would do it again - not today though," he said.

For Chambers, completing a rock climb is more than a physical accomplishment - it's a metaphorical feat, too. A roadside bomb in Iraq injured the 20-year-old U.S. Marine Corps lance corporal in February. The driver of a light armored vehicle, he suffered a brain injury and a shattered right heel that ultimately cost him his leg from the knee down.

"The three-ton engine next to me was thrown 40 yards, so that tells you something," said Chambers. "I'm extremely lucky to be here."

Chambers is spending a week in the Rockies with other recently injured Iraq war veterans as part of a program hosted by Challenge Aspen. Eighteen men are in town for the Aspen Wilderness Program, and after spending three days river rafting through Westwater Canyon on the Utah/Colorado border, they spent some time scaling rock up the Lincoln Creek valley.

Chambers has only had his prosthetic leg since mid-July, and learning to walk has been a hurdle.

"I was 200 pounds in February, and that's the last thing I remember," he said. "I woke up four months later, and had lost it all. I'm about 150 pounds now."

Chambers underwent 22 surgeries during that period, and while he wasn't in a coma, he says it almost felt that way.

"I was in a dream state. If I didn't like what I was doing, I would just go to sleep," he said. "I thought I would wake up again in Iraq and be late for post or patrol."

The Delta native went home for the second time since the injury on Thursday night to visit family and friends. He's an outpatient at Walter Reed Army Medical Center in Washington, D.C., and has also spent time at a brain injury facility in Tampa, Fla.

"I'm mentally stable enough not to go crazy, or I'd like to say I don't have it (post-traumatic stress disorder)," he said, laughing with a surprisingly good sense of humor.

The Aspen Wilderness Program is in its third year and, like many Challenge Aspen programs, it's recreation-based therapy, said program director Sarah Volf. It encourages the soldiers to test their physical skills, in turn building self-confidence they may have lost along with their leg or arm. In September, Challenge Aspen will host the first TBI outdoor rehabilitation program in the country.

"It's a way to work back into society," said Volf. "Nature is so therapeutic. The changes we've seen, even in five days, is incredible."

She points out Jake Altman as one of those cases. After five months of deployment in Iraq, the 20-year-old Army specialist's vehicle - the lead car in his convoy - was destroyed by a bomb.

"I didn't really feel pain when my hand was blown off," he said. Besides losing his right hand and forearm, both knees were severely injured, and physical tasks like rock climbing and rafting have been work - and fun.

"It's really boosted my self esteem and I think it's wonderful that they do this for the soldiers. It's inspired me to work harder," he says.

A support system is something Altman could use right now, considering his wife - a German native - and 10-month-old son are still overseas. He hasn't seen either since he left for Iraq, and he says securing a passport and dual citizenship so they can travel to America has been difficult.

"I still have fear but I just try to push through it," he said.

And that is one of the Aspen Wilderness Program's goals, notes Kristi Say, an occupational therapist at Walter Reed who accompanied the veterans to Aspen. It's her third summer participating in the program.

"The meaningful goal is to independence," she said. "That's breaking down all barriers, whether or not they're an able-bodied person or missing a limb. Some of these activities were a huge mental block before and it opens up the door to possibilities."