The Yakima is a decent trout stream. I don't know much about 'cause I never fished it. It is about a 2 hour drive over the hill from Seatown and locating a guide might be a handy thing. The Puget Sound (or should I say the Salish Sea) rivers open up on the 1st of June but there isn't much to fish for in them at that time of year. Sort of in between runs. Beaches are always good to fish for searun cutthroat and resident salmon. Again I don't know much about the beaches in the Seattle area, sorry. There is always the lowland lakes. Lotech gave you the best site to check on those. http://www.washintonflyfishing.com is another site with a knowledgeable membership you could post questions to. Let them know you are only visiting or you might get some flak. The site is a bit more liberal then FAOL and I don't mean liberal like left. It is more tolerant of language and things.