Ralston left hospital staff stunned as he explained his ordeal
A US rock climber used a penknife to amputate his own arm and escape to safety after a boulder pinned him down for five days in a remote part of the western state of Utah.
Aron Ralston, 27, and described as an experienced outdoorsman, was found by climbers on Thursday and airlifted to hospital.
Officials said that his condition was serious but that he would fully recover.
He had been hiking in Blue John Canyon near the Canyonlands National Park in Utah when his right arm was trapped by a boulder which came loose as he attempted to use it as a handhold.
On Tuesday his water ran out, and on Thursday he made the decision to sever his arm just below his elbow, applying a tourniquet and administering basic first aid before abseiling off a 70-foot (21m) ledge and beginning the hike back to his vehicle.
He was taken to hospital by a rescue helicopter - friends had alerted the emergency services when he failed to turn up for work.
At hospital, a calm Mr Ralston explained to stunned staff what had happened, adding that he had lost a lot of blood.
'Love of outdoors'
Calling Mr Ralston a "rare hero", Sergeant Mitch Vetere, of Emery County Sheriff's Office, said he was amazed by the climber's good condition considering the circumstances.
He also said that Mr Ralston had made the right decision to free himself, as the county's rescue teams might never have spotted him.
"Our rescue team said that they never would have seen him from under that boulder," he told the BBC.
"The only way we would have seen him is if we had stumbled into him."
Mr Ralston's mother said that her son, an experienced climber, survived because he was in peak physical and mental condition.
"He was able to rationally consider alternatives relative to his situation," she told the Associated Press news agency.
"His spirits are high and he anxiously looks forward to returning to his love of the outdoors."