He traces his life's path to a grenade thrown by a Viet Cong soldier one March night in 1969 when his 9th Combat Infantry Division ambushed 400 of the enemy.
The battle was "as close to hand to hand as you can get," he said.
Bauer, a non-commissioned officer at the time, had turned 21 about a month earlier.
"It felt like my brain was frying," Bauer, now 64, said of getting hit.
As the firefight raged around him, medics arrived and tied a tourniquet around his left hip, a signal to Bauer how badly he had been injured.
A swimmer and football player in high school, Bauer recalled living in a "slow-motion" world as he moved around on crutches and in wheelchairs.
He eventually would endure seven operations. Around the time of his sixth operation, Bauer contemplated suicide.
"The whole atmosphere tends to beat you down," the Oakland, Ca., native said. "Your self-image is shot."
A recipient of two Bronze Stars for heroism and two other military awards, Bauer said he considered throwing himself from the fourth-floor window of his hospital room.
"I was taking a checklist and just ticking off the things I couldn't do," Bauer said.
The need for speed
Nine months after he lost all but five inches of his leg, Bauer skied for the first time with his disability.
"For me, it was like the biggest high in the world," Bauer said.
Within months of the first ski trip, Bauer started volunteering to help other disabled veterans get the same feeling he had of the wind rushing by his face as he hurtled down a mountain.
After volunteering for 12 years, he became executive director of Disabled Sports USA.
He remains in the position 30 years later.
As part of his day-to-day duties, Bauer helps people with disabilities participate in sports, such as climbing, surfing and running.
"We really focus on the physical act," Bauer said. "That in itself has a really, really strong psychological effect."
In 2003, Disabled Sports USA formed Warfighter Sports to assist veterans disabled in the most recent conflict in Iraq, according to its website.
In its nine years, Warfighter Sports has helped nearly 5,000 veterans and their families participate in more than 30 sports.