if I understand what you are asking you want to look at Foreign Currency CD's and/or Deposit accounts.
In the US, there are very few institutions offering foreign currency accounts. One (of a very small number) in the US is Everbank. https://www.everbank.com/currencies
. I have no knowledge on residency rules. FWIW, I have positive, although not recent experience (pre-Lehman) with EverBank.
Canada however has a much greater choice for foreign currency accounts. AFAIK, almost all banks in Canada have some offering of foreign currency accounts. In fact, you've already stated your funds are in USD sitting in a Canadian bank. I have no knowledge on residency rules.