– The "buried treasure" found by a California couple out walking their dog—an estimated $11 million worth of rare gold coins from the 1800s—has started to be auctioned off. Last night at the Old San Francisco Mint, an 1874 $20 double eagle sold for $15,000, the AP reports. A few other coins were also auctioned there, and most of the remaining 1,400 are now on sale on Amazon.com and Kagins.com, according to the firm handling the sale. The anonymous couple, who found the coins on their own property, are also keeping a few. As for the money they make, they'll pay bills and donate to local charities—and the money from last night's auction will help turn the Old San Francisco Mint into a museum. About 60 of the coins will be displayed there, USA Today reports. It's still not clear where the coins, most of which are in mint condition, came from—the numismatist who valued the coins and is handling the sale says theories (none of which panned out) have linked them to stagecoach bandit Black Bart, outlaw Jesse James, and a heist at the San Francisco Mint. And, of course, there are people out there who claim the coins belonged to their distant relatives—one of whom has threatened to sue. But none of the stories so far is legit, according to federal officials.