Here's what the US Mint tells us
Amount of present gold holdings: 147.3 million ounces.
The only gold removed has been very small quantities used to test the purity of gold during regularly scheduled audits. Except for these samples, no gold has been transferred to or from the Depository for many years.
The gold is held as an asset of the United States at book value of $42.22 per ounce.
The Depository opened in 1937; the first gold was moved to the depository in January that year.
Highest gold holdings this century: 649.6 million ounces (December 31, 1941).
Size of a standard gold bar: 7 inches x 3 and 5/8 inches x 1 and 3/4 inches.
Weight of a standard gold bar: approximately 400 ounces or 27.5 pounds.
Construction of the depository:
How would any of us know if that is true or not?
Also we are informed by that the Fort Knox
...gold depository is second in the United States to the
Federal Reserve Bank of New York's underground vault in
Manhattan, which holds 7,000 metric tons (7716 tons) of gold bullion (225.1 million oz. troy), some of it in trust for foreign nations, central banks and official international organizations.
source Wiki.
Again, how would we
know for sure whether that is true or not?
Like so many other things we read or are told, we either take it as true on faith or we don't.