Even if you don't open a foreign bank account, these bank branches still might be able to exchange currency for you. If they are willing to do so you'll likely have to pay a fee, just as you would in the U.S. if you aren't a banking customer.
Use our branch finder and select "foreign currency" under 'products and services' to find your nearest branch. Just head over with your money and we'll buy it back. Over 2,500 branches won't need to see your purchase receipt, but smaller ones will.