Proof US Mint

The US Mint is one of the largest mints in the world, operating from headquarters in Washington D.C. and with four refineries in Philadelphia, Denver, San Francisco, and New York, as well as a storage depot at Fort Knox.

The plant in San Francisco is responsible for the production of all the US Mint's proof coins since 1968. Here they make the excellent collectable coins you can see below, creating the best coinage America has to offer.