Unclaimed property, like these gold coins, can be reclaimed online by going to https://ucpi.sco.ca.gov/UCP/Default.aspx Riches, Money, Coins, Gold, Generic (CBS)

SAN FRANCISCO (CBS / AP) — A treasure trove of rare gold coins that were discovered by a California couple out walking their dog last year went on sale Tuesday, with the first coin fetching $15,000 that will be contributed to turning San Francisco’s Old Mint into a museum.

The nearly 1,430 coins date from 1847 to 1894 and have been valued at more than $11 million. Most of the rest will go on sale on Amazon.com and Kagins.com later in the evening. Here are five things to know about the coins and their origin:

WHY ARE THEY SO VALUABLE?

Experts say paper money was illegal in California until the 1870s, so it’s extremely rare to find any coins from before that period. Additionally, most of the coins are in mint condition, having been stashed away seemingly immediately after they were minted. They were valued by Don Kagin, a numismatist who is handling the sale and marketing of the coins.

WHO FOUND THEM?

Kagin says the couple — a middle-aged husband and wife — does not want to be identified in part to avoid a gold rush on their rural Northern California property by modern-day prospectors. They discovered the coins in eight cans buried in the shadow of an old tree on the property. They plan to keep a few of the coins themselves and use the money from the rest to pay off bills and donate to local charities. Money from Tuesday’s auction will benefit the effort to turn the Old Mint into a museum.

WHERE DID THE COINS COME FROM?

Most of the coins were minted at the San Francisco Mint, according to Kagin. It’s not clear, however, who put them in the ground or how they were obtained, though theories have abounded. Kagin says people have linked the coins to stagecoach bandit Black Bart, outlaw Jesse James and a theft at the San Francisco Mint, but none of the theories has panned out.

WHAT IS IN THE COLLECTION?

The treasure consists of four $5 gold pieces, fifty $10 gold pieces, and 1,373 $20 double eagles. Among the coins that will be on display Tuesday is the crown jewel of the collection — an 1866-S No Motto $20 gold piece valued at more than $1 million.

HOW DOES THIS DISCOVERY COMPARE TO OTHER COIN FINDS?

Kagin calls this coin find the largest such discovery in U.S. history. One of the largest previous finds of gold coins was uncovered by construction workers in Jackson, Tennessee, in 1985 and valued at $1 million. More than 400,000 silver dollars were found in the home of a Reno, Nevada, man who died in 1974 and were later sold intact for $7.3 million. Gold coins and ingots said to be worth as much as $130 million were recovered in the 1980s from the wreck of the SS Central America. But historians knew roughly where that gold was because the ship went down off the coast of North Carolina during a hurricane in 1857.

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