MOUNT EVEREST BASE CAMP, Nepal – It's midnight, and Gary Guller is still up in his expedition tent, bundled into a sleeping bag and yelling into a satellite phone.

The roar of an avalanche splits the icy darkness, answered by a tinny din from the phone. Forty-five fifth-graders back in Texas are screaming in delight that a real mountaineer would share such an adventure with them from the top of the world.

The 36-year-old climber flashes a grin, delighted at more converts to his passion and his cause: The freedom to explore should be open to anyone, and there's nowhere better to prove it than the highest of his beloved mountains of Nepal.

"It doesn't take a lot of money, a lot of material things. It's people willing to get out and make the effort, being willing to work together and help and try," he said. "Even if it's going only 50 meters. Sometimes just one meter is enough. Sometimes, all it takes is getting off the couch."

The Austin resident took a team of people with disabilities to Everest's base camp this spring to prove just that, and he's now poised to take his message to its summit.

Joined by two other American climbers and a small team of Nepalese Sherpas, Mr. Guller hopes to stand on the peak of the 29,035-foot mountain in the next few weeks. If successful, he would be the first person with one arm to reach the top of Everest.

It would complete an odyssey that began at age 12, when he was captivated by a photo of a snow-rimmed peak on the trail to Everest. "I thought, 'One day, I'd like to see that. One day, I will,' " he said.

He roped up for his first rock climb the next year, exhausting himself on a 40-foot pitch near his hometown of Gastonia, N.C.

At 15, he talked his parents into sending him to mountaineering school and then got a job helping underprivileged kids learn outdoor activities, including climbing.

"That was a start," he said. "What appealed to me then and now is that sort of sense of accomplishment, letting other folks experience some of the pleasures that I can show them, of something that they wouldn't normally do."

The accident: By his early 20s, he'd climbed across California and the Southwest and been in the Alps. After a college stint spent mostly climbing, he ended up at an Arizona school specializing in outdoor education.

He and his best friend talked professors into letting them organize a climb of Orizaba, a volcano in Mexico, as an independent study project. So one piercingly bright morning in 1986, Mr. Guller, his friend and another student were roped together at 18,000 feet on the ice-rimmed mountain, nearing the summit.

Mr. Guller said the lead climber somehow peeled off a short vertical section, pulling them all down. Then came the realization that they were falling far too fast.

He said he dug his ice ax into the slope, and the others hurtled past as he held onto it, its strap around his left wrist. The ax initially held, but he passed out after his friends' weight ripped the nerves controlling his left arm from his spinal cord. He later learned that his neck was also broken in several places.

He came to in a scree field with his friend trying to wake him. They had fallen about 2,000 feet, and neither could walk. Their companion was hundreds of feet below with a broken hip.

As darkness came on, he said, he and his friend hugged each other and fell asleep. His friend cried out in the night and was dead by morning. Mr. Guller said he and the other climber waited two days before being found by searchers so sure they'd be dead that "they only brought body bags."

Coming to terms: A neurosurgeon told him he'd never regain use of his arm. He had experimental surgery but ended up only with excruciating pain in his left shoulder.

He had more surgery to deaden the nerves, and then began trying to get himself back into shape.

"You saw something that he wanted to do so bad, and nothing was going to get in his way. Not even losing a limb," said his younger brother David. "He would spend hours at the gym, just driving himself to the point of physical exhaustion. It was almost a hush-hush situation with our parents, not something ever talked about. But as a brother, I knew: He's going to go up a mountain again."

In 1989, trying to regain "that free, athletic kind of life," Mr. Guller said he decided to have his arm amputated.

It was easy "from a physical point of view," he said, but it wouldn't be until he was asked to speak at a convention of people with disabilities in Texas in 2001 that he would come to emotional terms with what had happened.

"That was a big turning point for me. I think I've wasted too many years, not facing up to my injury," he said. "I've begun to look back and realize how long I have tried to hide the fact that I had only one arm."

After the amputation, he said, he delved back into outdoor sports, hiking and camping across Canada and the western U.S., and then going to Europe to search for some semblance of all that he'd lost.

Persistence: He settled in England, hiking in winter in the mountains of Wales and returning to climbing in earnest with ice climbing in Scotland. He discovered Nepal in the early '90s, and was so smitten with the country and people that he was soon leading treks there.

In 1997, he signed on to a friend's expedition to climb Lhotse, a peak adjoining Everest. Shortly after they reached the mountain, his friend died in his sleep of a heart attack.

Mr. Guller returned to England and learned his wife had filed for divorce, citing his frequent absences.

"I don't know if I could give up what I do for anyone. That comes across as very hard," he said. "I think the majority of people don't really get to experience what they really want to do, though."

He flew back to Nepal and fell in love with Joni Rogers, a speech therapist from Texas.

They decided to move to Austin to tap into the U.S. adventure-travel market. They married and mapped out a plan. Mr. Guller would lead treks and build up their company, Arun Treks and Expeditions, while readying himself for his ultimate goal: going up Everest.

"The one part that was missing was my head," he said. "I didn't have the mental control over what had happened [in 1986] yet. I was still kind of running from it."

He went to climb Everest in 2001. With only one arm, it was far more difficult to get through sections like the Khumbu icefall, a highly unstable ice floe at the base of the mountain. There, climbers traverse 25 to 30 aluminum ladders stretched over deep crevasses and up massive ice walls, balancing heavy boots with sharp metal crampons while holding onto fixed safety ropes. Having to use one arm to negotiate the ladders and safety ropes was difficult, but Mr. Guller said he compensated with footwork and patience.

On one trip through the icefall, he and his climbing Sherpa, one of his closest friends, narrowly escaped being swept away by an avalanche. Hearing a roar overhead and seeing a wall of snow hurtling toward them, Mr. Guller said, Nima Dawa Sherpa threw sacred rice blessed by a Buddhist lama, told Mr. Guller to hold his breath and hugged him against an ice wall.

"What went through my mind was, 'I can't believe this.' " he said. " 'I survived my neck being broken. I got here, and this is how it's going to end?' "

They were unscathed, and got up to 24,000 feet but ultimately had to abandon their summit bid when shifting ice knocked out crucial fixed ropes.

Confidence renewed

Back in Texas, Mr. Guller agreed to speak to the Coalition of Texans with Disabilities. He said it was the first time he'd talked publicly about how he lost his arm, and he was initially terrified of being with so many people with disabilities.

"Even I didn't know his whole story," Ms. Rogers said. "I'd only gotten pieces of it. It was an extremely emotional process just to write the talk that he gave."

Afterward, Mr. Guller began brainstorming with the coalition's director, Dennis Borel. They assembled Team Everest 03, and their goal was audacious but simple: Carry to the highest point on earth the message that people with physical challenges have unlimited potential.

They hoped to raise $1 million, but the poor economy made fund raising so difficult that they had to pare the expedition budget. At the last minute, they scrambled to raise enough to send the minimum amount of equipment they needed in Nepal. Mr. Borel said they remain $13,000 short of covering expedition costs.

Once under way, Mr. Guller said, virtually everything about the trek exceeded his hopes. Seven of his fellow Americans with disabilities reached base camp with him, and the group drew national attention and praise from every climber and trekker they met along the way.

"People do get it," he said. "What we're doing is pushing the same envelope that Sherpas did years ago and climbers did years ago."

He reveled in showing teammates the mountain kingdom.

In the tiny settlement of Dugla, he pointed out a particularly stunning peak – the one he'd seen in pictures as a boy.

"It's like a dream, regardless of anybody's ability or disability, to see people's faces when they see these mountains," he said, his eyes tearing up as he watched his teammates. "And working together like this, it can truly change the world.

"In Austin, they're fighting to keep basic human services for people just like these," he said. "I wish we had the ways and means to have direct, live satellite links to the Legislature. I think they'd start maybe realizing these people are just like them. They're not asking for the world. They're asking for fairness."

The day they left base camp, a passing Sherpa stopped him on the trail to hand him a package from Katmandu. Mr. Guller sat down and ripped it open like a child opening a present and then stared at the Nepali government document inside. It was his team's permit to climb Mount Everest.

"I've waited all my life for this," he said. "Since I was 12 years old."