The Spanish King, Charles II, decreed that all treasure in North America that could not be brought back to Spain before the American Indian revolt of 1685 was to be buried at least 30 feet deep or 30 feet of tunnel from the outside of the mountain. Penalty for a burying treasure too shallow was death! Hundreds of Spanish mines “pickled” (stored) refined bars of gold and silver at least 30 feet deep. Extensive death traps were incorporated to prevent the occasional robber from stealing the treasure (Do your research of “Death Traps” before digging for treasure!). Spain did send expeditions back to open old mines and send refined bars back to Spain. Many sites are still waiting to be found as the ownership of the land changed hands from French to American, Spanish to American, and many miners never made it back to Spain with the secret code to relocate the hidden caches due to time, death, disease or tragedy
Anyways most of these caches where discovered by the KGC and the symbols where updated replaced or moved. Look it up.