>>99446274 reason
1) Nazi documents on their Antarctic base
2) operation high jump
3) disclosure of advanced nazi U-boat designs
4) south American coast towns reported interactions with Nazis doing supply runs after the end of the war
Most likely scenario: there was a small holdout base. High jump "failed" only due to poor planning for the cold. US mopped up and repurposed the facilities then built their own. The reason travel over the center of the continent is restricted is a standard no-fly zone over military bases.
