Re: washington state
A few questions will help narrow down your options:
What is your intended game that you are planning on hunting?
What is your weapon choice?
Not trying to tear you down but there are a lot of places to backpack in WA state and depending on what weapon you choose and what is in season will help narrow it down.
For example if you want to hunt deer in the Modern Firearm "High Buck Hunt" that runs from Sept. 15-25; your choices are some classic high country backpacking areas: Alpine Lakes, Glacier Peak, Pasayten, Henry Jackson Wilderness, Lake Chelan Recreation area, and Olympic Peninsula. This is straight from the hunting pamphlet. What you need to do is some research on maps, google earth, find some logging roads or trailheads that will get you close to the GMU you intend to hunt.
If you are planning on an Archery hunt the options are even bigger because of the length of the season and the access to areas.
And of course some of the best backpacking scenery in the state is on National Parks that don't allow hunting: North Cascades, Mt Rainier, and Olympic National Parks.
Maybe you have already found all the info you were looking for but maybe this will help.