Raul Fernando Gomez Circunegui set out to cross the mountains from Chile to Argentina on foot in May because his motorcycle broke down but then lost his way during a snowstorm.
Argentine officials from the northwestern province of San Juan stumbled upon Mr Gomez in a shelter 9318 feet above sea level when they travelled there to record snow levels.
A feeble Mr Gomez was able to hobble over and open the shelter's door, alerting the crew to his presence.
San Juan Governor Jose Luis Gioja said: "The truth is that this is a miracle. We still can't believe it. We let him talk to his wife, his mother and his daughter. I asked him: 'Are you a believer?' He told me, 'no, but now I am'."
Sugar, raisins, rats and the shelter's leftover supplies kept Mr Gomez alive through the Southern Hemisphere's winter. He lost 45lbs during the ordeal and is dehydrated.
A doctor who examined Mr Gomez was surprised by the man's resilience, saying: "He's a patient with high blood pressure, a history of smoking and signs of undernourishment but he's going to be fine and in a few days we're going to discharge him."
In 1972, a plane carrying an Uruguayan rugby team to Chile crashed in the Andes and some survived by eating dead bodies.