"Some of these targets have not been in production for 73 years (closed by Federal government edict the War Production Board Limitation Order No. 208 in autumn 1942 also known as the Gold Closing Act),..."

So, there were producing precious metals mines indirectly shut down by the government early on in WWII, and many have been lost, or are yet to come back on line.

In the following link, read the section beginning "No mines have any minerals left." The first paragraph thereafter begins... "False – This is the biggest myth that is pushed on people. In fact, many mines have many millions of dollars in reserves (reserves are minerals left in place) just waiting to be extracted. So why did the miners just abandon gold, platinum, silver and other metals? Our own federal government took away their mines. Here is a brief history lesson:"

For the details go to https://www.goldrushexpeditions.com/working-abandoned-mines/

Go to the 3rd or 4th section, and read especially the part in bold print.

VP