All four people on board the plane -- the pilot and three engineers from the Pan American Argentina Oil Company -- were killed when it crashed into the Colhue Huapi lake on October 19, 1964.
Emergency workers managed to pull the victims' bodies from the wreckage at the time, but never recovered the plane, a Piper Apache Twin Engine, which sank into the lake.
Now, more than 50 years later, a local has found the wreckage after spotting a wing poking out of the ground in an area where the shallow and shrinking lake has evaporated.
The Colhue Huapi lake has been retreating for decades, steadily evaporating for various reasons including lack of rain and pressures on the local water supply.
The wreckage had eluded an exhaustive search from the air and water by Pan American Argentina in 1964 and another attempt to find it in 1980, local resident Julian Bochatey yesterday told newspaper Cronica.
Bochatey, who helped dig out the plane, said locals matched its registration number with that of the missing flight and informed aviation authorities.