Why is the US government hoarding gold?

From How Gold Was Money--How Gold Could Be Money Again, by Richard H. Timberlake

For the last 60 years the Treasury has hoarded thousands of tons of gold, and has only disbursed it to foreign central banks and governments; and for the last 20-plus years the gold has been a largely inert mass of no use to anyone. Even Treasury officials are largely ignorant of its physical details.

Suppose, however, that an astute politician promised to return the gold to the people as a means of economizing on the inventory of "surplus" government commodities. Can anyone imagine that such a plank in a political platform would be unpopular? "No, no," the candidate would declaim, "I am not buying votes with gold. I would not stoop to that. I simply want to economize government operations and, at the same time, return a useful commodity to the public so that people can use it as money if they wish to do so."

Or for anything else as well.