Here is an interesting question that doesn't come up to often. If you were to find some buried treasure, who would get to keep it? The Answer often lies in primarily in jurisdiction being a matter of property law. Most American law originates from English Common Law, but that is not the case with "Treasure Trove" issues in the US. Instead, most applicable laws originate from legal precedent stemming from lost or owner less items.

Claims in the United States between 1904 and 1948 have tended to lend themselves to the finders favor. The landowner generally did not have any legal claim to an ownerless item. Since 1948 there simply has not been much cause for new precident on the Treasure Trove rule. Some feel that the finders should still receive the items, while others feel that a few rulings in the early 20th century do not overrule private property rights. Certainly if you were found to have tresspassed on a property, the items may not be available for your claim.

Still, if you find a box of Gold Coins, just keep your mouth shut.