Preemption? They're a state agency. .290 doesn't apply to them. Or are you referring to the highest preemption statute, the state constitution?[/COLOR]
A State agency can not make law and as far as I know they must follow state law so they are left with making rules which I do not see any rules posted.
The first sign on the left allows lawful weapons since it only says unlawful weapons are prohibited.
The middle sign is just there for the intimidation factor it is very hard to meet the legal requirements of intimidating a public servant and if you go that far then you may want to review your conduct anyway.
The third sign prohibits any and all dangerous weapons since a firearm is not a dangerous weapon unless it is furtively carried, firearms are allowed especially an openly carried firearm since that would be the opposite of furtively carried.
RCW 9.41.250
Dangerous weapons — Penalty.
(1) Every person who:
(a) Manufactures, sells, or disposes of or possesses any instrument or weapon of the kind usually known as slung shot, sand club, or metal knuckles, or spring blade knife;
(b) Furtively carries with intent to conceal any dagger, dirk, pistol, or other dangerous weapon; or
(c) Uses any contrivance or device for suppressing the noise of any firearm unless the suppressor is legally registered and possessed in accordance with federal law,
is guilty of a gross misdemeanor punishable under chapter 9A.20 RCW.
(2) "Spring blade knife" means any knife, including a prototype, model, or other sample, with a blade that is automatically released by a spring mechanism or other mechanical device, or any knife having a blade which opens, or falls, or is ejected into position by the force of gravity, or by an outward, downward, or centrifugal thrust or movement. A knife that contains a spring, detent, or other mechanism designed to create a bias toward closure of the blade and that requires physical exertion applied to the blade by hand, wrist, or arm to overcome the bias toward closure to assist in opening the knife is not a spring blade knife.