RCW 77.15.150: Poison or explosives—Unlawful use—Penalty.

(1) A person is guilty of unlawful use of poison or explosives if:

(a) The person lays out, sets out, or uses a drug, poison, or other deleterious substance that kills, injures, harms, or endangers fish, shellfish, or wildlife, except if the person is using the substance in compliance with federal and state laws and label instructions; or

(b) The person lays out, sets out, or uses an explosive that kills, injures, harms, or endangers fish, shellfish, or wildlife, except if authorized by law or permit of the director.

(2) Unlawful use of poison or explosives is a gross misdemeanor.