The cache of rare Gold Rush-era coins is worth more than $10 million, a currency firm representing the pair said on Tuesday.
The 1,400 gold pieces, dating to the mid- to late 1800s and still in nearly mint condition, were discovered buried in eight decaying metal cans on the couple's land in April, said coin expert David McCarthy of currency firm Kagin's.
"We've seen shipwrecks in the past where thousands of gold coins were found in very high grade, but a buried treasure of this sort is unheard of," McCarthy said. "I've never seen this face value in North America, and you never see coins in the condition we have here."
Donald Kagin, president of Kagin's Inc., a numismatic firm that specializes in U.S. gold coins, announced the discovery. The company represents the couple, who want to remain anonymous for fear treasure hunters will descend on their property in Northern California's so-called Gold Country, named after the state's 1849 Gold Rush.
The couple, identified only as John and Mary, had been walking their dog when they came across a rusty metal can sticking out of the ground and dug it out.
The rare and perfectly preserved U.S. gold coins date from 1847 to 1894 and have a face value of more than $28,000. They could sell for more than $10 million.
The previous largest reported find of buried gold treasure in the U.S. had a face value of $4,500. It was discovered by construction workers in 1985 in Jackson, Tenn., and eventually sold for around $1 million.
McCarthy said Kagin's will sell most of the coins on Amazon for the couple and that a sampling will be displayed at the upcoming American Numismatic Association show in Atlanta later this month.
The "Saddle Ridge Hoard," as it’s being called, includes the 1866-S No Motto Double Eagle valued at around $1 million.
The couple told Kagin they couldn’t believe they had made such a big discovery and were grateful for it.
“I thought any second an old miner with a mule was going to appear,” John said in an interview posted on the company's website.
"It was like finding a wonderful hot potato," Mary added. "I never would have thought we would have found something like this; however, in a weird way I feel like I have been preparing my whole life for it."
The coins were authenticated, graded and certified by Professional Coin Grading Service in Irvine, Kagin said.
The $20 gold pieces appeared to have been new when they went into the ground and had suffered little damage from being in the soil for so long.
McCarthy said the couple wisely refrained from cleaning the coins themselves and brought a sampling of them to him in little baggies, still covered in soil.
"I picked up one of bags. It was an 1890 $20 gold piece. It was covered in dirt," McCarthy said, recalling when he first saw one of the gold pieces. "An area of the coin was exposed and the metal looked as if it had just been struck yesterday."
His company took what became known as the "Saddle Ridge Hoard" to an independent coin-grading service, which found that it was comprised of nearly 1,400 $20 gold pieces, 50 $10 gold pieces and four $5 gold pieces.
"The Saddle Ridge Hoard discovery is one of the most amazing numismatic stories I've ever heard," said Don Willis, president of Professional Coin Grading Service. "This will be regarded as one of the best stories in the history of our hobby."
The couple said they plan to keep some of the coins and sell others with the intention of donating part of the proceeds to charity.
More importantly, they said, they will use the money to hold on to their home. They did not explain further.
"Whatever answers you seek, they might be right at home," Mary said. "The answer to our difficulties was right there under our feet for years."
"Don’t be above bending over to check on a rusty can."
Los Angeles Times and Reuters contributed.