If you're curious what the dollar is worth today, it's best to check the website (keeping in mind that even the bank will take a couple percentage points for themselves).

If you're down here shopping many stores and restaurants in Blaine take Canadian dollars. As you move into Bellingham you may have more difficulty, or you may get a crummy exchange rate. In my experience, before moving to the US, the best rate I got was on my RBC Visa. The exchange always seemed to be fair and Visa is accepted pretty much everywhere, except for Costco.

At Costco, it's the usual Amex or bank card. I overheard the cashier yesterday telling a Canadian that your debit card will work as long as it has the Visa symbol on the back. If you don't want to risk it, and don't have an Amex, then it's best to have US Cash.

If you're looking to exchange money on the way down there's a Calforex location right before the Peace Arch Border Crossing. Click here for address and hours of operation.