The only thing more mysterious than the identity of the couple who stumbled upon an estimated $10 million in US gold coins while walking their dog on their California property: Where did the gold come from? The San Francisco Chronicle floats a theory with all the intrigue and illegality you could hope for: Historian/coin collector/fishing guide Jack Trout provided the paper with a passage from the Bulletin of American Iron and Steel Association that references a $30,000 turn-of-the-century gold heist from the San Francisco Mint that he believes is linked to the coins. Lending credence to the theory: The unearthed 1,427 gold coins, dated 1847 to 1894, were mostly uncirculated and in chronological order, suggesting they hadn't entered the public realm. And though they are worth millions today, their face value is $27,000, which roughly syncs with what was taken from the mint.
Trout also points to the buried stash's 1866 Liberty $20 gold piece not emblazoned with "In God We Trust"; he suspects it was a private coin created by a mint manager that never left the mint. "For it to show up as part of the treasure find links it directly" to the mint heist, he says. But the couple's coin broker is no fan of the mint robbery theory, telling the Chronicle he'd expect the haul would have included coins dated closer to the heist date. But a former SF Mint detective sees it as plausible: "Downstairs, we had vaults where we kept old coins that hadn't been put into circulation." PJMedia further digs up a 1906 congressional report that indicates mint clerk W.N. Dimmick was convicted of the mint theft, but the document doesn't state whether Dimmick revealed the coins' location, or if they had been recovered. ABC News notes that if the coins are indeed purloined government property, the couple may owe Uncle Sam more than a heck of a lot in taxes: They may have to turn over the entire haul, and get a finder's fee in return. (Read more discoveries stories.)