Ahem...to be fair:
http://en.wikipedia.org/wiki/Operation_Deep_Freeze
"Operation Deep Freeze (OpDFrz or ODF) is the codename for a series of United States missions to Antarctica, beginning with "Operation Deep Freeze I" in 1955?56, followed by "Operation Deep Freeze II", "Operation Deep Freeze III", and so on. Given the continuing and constant US presence in Antarctica since that date, "Operation Deep Freeze" has come to be used as a general term for US operations in that continent, and in particular for the regular missions to resupply US Antarctic bases, coordinated by the United States military."
Now, mind you this wasn't hugely secret, and it was in the Antarctic. But still.