Sorry to hear about your injuries. Wish I were more familiar with the fly fishing only fisheries of Washington so that I could fill you in--'cause I would. I suggest getting yourself a copy of the regs and trying out several different locations. Some fly fishing specific magazines and books would probably be a big help with research too. Don't let anyone discourage you--fish away! Just don't expect a warm reception from other anglers. Unless Oregon and Washington fish are totally different--which I doubt--you can expect some banner days.

Good luck!