There is some really great waterfowling south of you. Skagit Bay, Grays Harbor and Willapa Bay. Inland the Pot Holes area, call Mardon Resort, they have blinds(guided and unguided hunts), cabins and restaurant. I never hunted with them but have camped on their place and hunted on my own. The only guide I knew of on the south coast died but there are others.
Fun on the south coast with the oldtimers
North Dakota in the Devils Lakee area has plenty of great waterfowling and lots of guides for both on the water and field hunts.
Idaho on the Snake can be great.
Other renowned places are Arkansas, Louisiana, Texas.
East of the Mississippi I'm lost
Oops, years ago I used to hunt ducks at Horicon Marsh and had good hunting again self guided but there are some guides and clubs around there. I guess that is east of the Mississipi.