One note - knife laws in Washington state are vague but, for the most part, fairly reasonable. A quick search shows that, in several counties and cities, any blade length over 3" could (not will, but could) be considered a "dangerous weapon", especially if it "causes alarm" in someone who sees it.
If it's anything like Chicago, you'll probably be fine with a blade length no longer than 4". Illinois has rather decent knife laws but the city of Chicago has placed further restrictions on them, such as a maximum blade length of 3". That being said, those additional laws typically only come into play as secondary offenses (when police arrest gang bangers, they can add the knife offense). So I have no concern carrying my 3.5" bladed Gerber into the city with me because the police really don't care about me.
That being said, my new Kershaw Leek has a 3" blade which I bought specifically to adhere to all Illinois knife laws.
Just something to keep in mind when you're deciding on your EDC blade.