Thought it might seem counterintuitive, there is actually more than one official currency in the United States. Of course, the federal bills that we all know and use. And a second, lesser known local currency.

In the area known as the Berkshires, a mountainous, 98-mile stretch of western Massachusetts and northwestern Connecticut, also prints their own official money. Known as BerkShares, the initiative was launched in 2006 as a means of bolstering the local economy and incentivizing community-mindedness. Here’s how this peculiar local U.S. currency came to be.

Make no mistake: BerkShares are not funny, Monopoly money. In addition to being accepted by over 300 locally owned businesses in the Berkshires region, the currency is backed by U.S. dollars on reserve at area banks. And Berkshares are even exchangeable for USD at six branches of those banks. Many of those businesses offer discounts to customers paying with BerkShares, and the exchange rate is fair as well: One dollar will get you one BerkShare. If and when you need to exchange them for USD, you can do so at the same rate and pay a modest 1.5% exchange fee.

In addition to their role in building up the local community, Berkshares are aesthetically pleasing. They feature the likes of W. E. B. Du Bois, Herman Melville, and Norman Rockwell — luminaries who were all born and raised or spent significant time in this bucolic area. 

The notes themselves come in denominations of one, five, 10, 20, and 50. More than 10 million BerkShares have been issued since 2006, and there’s a directory listing every business that accepts them. The list includes museums, restaurants, playhouses, grocery stores, doctors, and inns, just to name a few.

You may be wondering, though, how BerkShares are considered legal. Interestingly, while the U.S. dollar is the only legal tender in the country, local currency is allowed under federal law as long as the currency is paper scrip, not coins, and doesn’t too closely resemble the U.S. dollar. 

So next time you visit the Berkshires and a cashier hands you some different looking money… Rest assured that you are not being taken advantage of!