(NEXSTAR) — If you check your cup holders, coin purse, or piggy bank, there is a very good chance you’ll find a state quarter — the U.S. Mint produced 34.3 billion during the 10-year period the quarters were released. 

While every state has a quarter, one is proving to be of increased interest recently.

First, it’s important to understand the process of making the state quarters. 

During the program, which ran from the 1990s through 2008, states submitted designs for their own quarters. In 33 states, the governor selected the final design and in 17, citizens made the selection.

Once the design was finalized, the coins were minted in one of three cities: Denver, Philadelphia, or San Francisco. You can tell where any quarter was minted (with the exception of some older ones) based on the small letter to the right of President George Washington’s head. 

Where the quarter was minted can have an impact on its collector value, according to Coin Trackers. That’s especially true for some, including Wisconsin. 

If you aren’t familiar with the Wisconsin state quarter, it features a cow, a wheel of cheese, an ear of corn, and the state’s motto, “Forward.” An example can be seen below. 

A 2004 P-mint Wisconsin state quarter. (Addy Bink/Nexstar)

But on some versions of the quarter, the ear of corn is slightly different, sprouting an extra leaf on the left side. That extra leaf will be either “high” or “low.”

It isn’t clear how this variation became available, but it has only been found on D-mint quarters (minted in Denver), Heritage Auctions explains. Both error coins are extremely hard to find, though, as it was first noticed shortly after it was released in 2004. 

If you are lucky enough to find one, it could be worth a pretty penny. Two separate quarters, one with an extra high leaf and the other with a low leaf, both sold in mid-August for nearly $160 at Heritage Auction. Another low leaf sold in early 2020 went for $6,000. Others have sold for hundreds of dollars.

Wisconsin state quarters, error or otherwise, can be difficult to find — they were the third-fewest produced after Oklahoma and Maine. 

There are other error state quarters that can be valuable to collectors. Several Minnesota quarters were minted with an extra tree, but the error was far more common than Wisconsin’s extra leaf, according to Ned Ludd Coins. A few District of Columbia quarters had extra lines on Duke Ellington’s sleeve, while some state quarters were accidentally struck on other coins, or vice versa. 

In general, any state quarter will be worth only its intended 25 cents. Some quarters in mint condition can be worth anywhere between $1 and $15, depending on the state and where it was minted, according to Coin Trackers. If it is silver proof, your quarter’s value could skyrocket to as much as $55.

How can you tell if your quarter or any money you’ve been collecting is worth more than its minted value? 

“The answer is not always obvious,” Dustin Johnson, Vice President of Numismatics (the study or collection of coins, paper money, and medals) at Heritage Auctions previously explained to Nexstar. “Odd items are always set aside but that doesn’t make them rare or terribly valuable.”

It’s best to take your money to a verified coin expert, like Heritage Auctions, which can evaluate your item for free.