Why isn't the Valley of the Vanished mentioned in the later stories? Some people will argue the gold had run out, that there wasn't anything left for the Mayans to send out to Doc Savage. But there may be another explanation.

With the advent of World War II it now became harder to move wealth around from one country to another without attracting unwanted attention. Governments were watching for funds that would be used for subversive activities in the beginning.

After the defeat of the Nazis, the search was on for the lost treasures and wealth of Europe. Any attempt by Doc Savage to utilize the golden treasure of the Valley of the Vanished would have eventually brought the hidden Mayan civilization to the attention of many of the world's governments. The Valley would have been discovered and the Mayan civilization that existed in the valley would have been destroyed.

Did Doc Savage need the gold from the Valley of the Vanished? Probably not. In the course of his adventures he acquired a considerable fortune. By the time the war began the Mayan gold was unnecessary due to his already massive wealth.

By the end of 1936 Doc Savage had accumulated an incredible amount of wealth. He was receiving regular shipments of gold from the Valley of the Vanished. In The Red Skull, August 1933, we are told that the value of an individual shipment is as much as five million dollars. Converting this to current dollars using a flat inflation rate of four percent per annum we arrive at a value just short of seventy-two million dollars sixty-eight years later in 2001.

If we assume the Mayan gold was delivered four times a year and each shipment had an average value of three million dollars and that twenty-eight shipments were carried out from 1933 to 1939 we would have an amount in gold equal to eighty-four million dollars in 1939 dollars. That amount would be in excess of $1.2 billion in 2001 dollars. $1,200,000,000. To give some idea to the value of this wealth, consider the fact that the cost of building the Empire State Building, including land, was forty-one million dollars.

This amount does not even include the incredible treasures accumulated in the course of the adventures during this time frame. The treasure from the Oceanic, the diamonds from the Lost Oasis adventure, and the Sargasso Ogre treasure to name a few.   The Oceanic treasure alone is valued at $50,000,000 in The Phantom City.  The Sargasso Ogre treasure comes in at a meager six to seven million dollars.  This is the same amount for the treasure found in The Brand of the Werewolf.

Pey-deh-eh-ghan's treasure is immense as we see in Resurrection Day (November 1936).  Monk counts over one hundred diamonds in the cache.

The diamonds acquired from the Lost Oasis adventure alone form the core of an unimaginable wealth. We are told that there is such a large quantity that the treasure must be disposed of a few at a time in order not to flood the market. In fact, in The Sargasso Ogre, we are told that the diamond fortune is enough to purchase some of the smaller European countries!

After obtaining this incredible fortune why would Doc Savage put his Mayan friends and their civilization in danger by continuing the gold shipments? He would not and that, in my opinion, is why we don't read about the gold shipments in the later adventures.

Even with the operating expenses of the Crime College, the Hidalgo hanger/boat house, the Fortress, the headquarters, and Doc's fleet of planes and such there would still be plenty of money left over.

Time after time we find in the course of an adventure that Doc has purchased a considerable interest in a particular concern. In Pirate of the Pacific we find out that Doc has an interest in the shipping company. In Red Snow it comes out that Doc owns several chemical plants. These are all going concerns. It is safe to assume that the holdings were worth many times their original purchase price after the depression ended and the economy picked up again.