Who hasn't, at one time or another, thought of spending the summer working in Alaska, or some other far-off place? Me, included! If you can, it's a good idea to start as early as December to look for summer work, and mid-summer for the winter. By February, the hiring cycle is in full swing, because most of the resorts and such like to have a full crew scheduled as soon as possible. Some as early as March.
This listing is far from complete, but I will add more as I find them and have the time.