I'm set up as USD currency. Any ideas? All other orders are USD. This customer lives in Colorado.
That's usually the currency the Buyer chose when they checked out. They could live in both countries, or be in the process of moving.
The buyer has their currency set incorrectly.
@EEECrafter: The buyer could live in a different country and is sending a gift or perhaps they are using a credit card in a different currency.