While walking their dog, a couple from Northern California struck gold — literally.

Last spring, the anonymous couple dug up rusty tin cans with 1,427 gold coins, dating from 1847 to 1894. Nearly every coin was in mint condition and has never been circulated, according to the Professional Coin Grading Service of Santa Ana, which recently authenticated the coins.

Though the face value of the coins came out to around $27,000, rare coin experts like Don Kagin, a veteran numismatist and representative of the couple, told the AP that some of the coins could fetch nearly $1 million apiece — making it one of the largest such discoveries in U.S. history.

To avoid a modern-day Gold Rush — a swarm of amateur prospectors with metal detectors in tow — the middle-aged husband and wife want to remain anonymous. They found the coins on a rural property in a hilly area of California’s Gold Country that they have lived on for years, but they haven’t released any information about the property or its ownership history. They have simply said that they live on a section of the property they have nicknamed Saddle Ridge.

“Their concern was this would change the way everyone else would look at them, and they’re pretty happy with the lifestyle they have today,’’ Kagin told the AP.

Before the couple sells the coins on Amazon, they plan on loaning some to the American Numismatic Association for its National Money Show. They will use the money to pay off bills, while also anonymously donating some to local charities. Kagin has also said they plan on keeping a few of the coins as keepsakes of their incredible find.

Perhaps they shouldn’t be too quick to spend it. There have been instances of the U.S. government claiming golden coins found by citizens. In 2011, a judge in the Eastern District Court of Pennsylvania ruled that 10 gold coins worth $80 million dollars belonged to the U.S. government after the U.S. Treasury seized the coins from a family in Pennsylvania, claiming the coins were stolen. It remains to be seen if the coins the anonymous couple found were also stolen.

The moral of the story, according to the anonymous wife: “Don’t be above bending over to check on a rusty can.”