Be very careful with open carry in WA; especially W WA. "Alarm" is vague and hard to quantify and I am sure that if I open carried in my area there would be all kinds of "alarm"!
RCW 9.41.270
Weapons apparently capable of producing bodily harm—Unlawful carrying or handling—Penalty—Exceptions.
(1) It shall be unlawful for any person to carry, exhibit, display, or draw any firearm, dagger, sword, knife or other cutting or stabbing instrument, club, or any other weapon apparently capable of producing bodily harm, in a manner, under circumstances, and at a time and place that either manifests an intent to intimidate another
or that warrants alarm for the safety of other persons.