I got the stuff below from the Washington State license and fees section License and fees
Migratory Bird Permit $16.50
Migratory Bird Authorization $13.20
Does one need both to hunt waterfowl?
Also what is a Discover Pass? $33.00
You still need to pick up the Federal Duck stamp as well. Don't forget that one. The $13.20 just gets you the authorization for SW Wash. Goose, SD, B, SG, BT if you want to hunt those. If your not you don't have to buy it. You still need to pay an additional .$50 per tag as mentioned if you want sea duck, brant, SW Wash. Goose for 2A/2B, snow goose or band tailed pigeon.
The WDFW pass will only work on those lands. You will have to get the discover pass if you go on any non WDFW or DNR lands. Don't leave the discovery pass in the window at all times or the print will fade away and you will just have a piece of blank paper.