There are probably some others than can help more than I might but, Squaw Creek is a refuge/no hunting allowed, I think. There are a couple very popular public hunting areas in the northern part of the state. One is Grand Pass Conservation area another is Bob Brown Conservation Area. Both are especially for waterfowl hunting. For a weekend hunt, the trick is having a reservation that you have to apply for in Sept. During weekdays you have a much better chance at drawing in, as they only allow so many hunters per day. There are others but those are the most productive north central and northwestern managed areas. Eagle Bluffs south of Columbia usually holds a respectable number of birds as well.
Here's the link to main waterfowl hunting page. It has info on all the managed areas as well as some info on the Reservation System.
The atlas in this website might be helpful too.
Rest in peace my friend... Mocha- Jan 20th, 2001-Feb 1st, 2009.