Does private property need to be posted in Washington State in order for trespass rules to be enforced?
No. If the land has indications of private ownership, such as buildings, fences, or signs, you cannot go onto the land without the landowner’s or tenant’s permission, if you go onto land despite seeing or being aware of No Trespassing signs, you can be cited for trespassing. If you trespass on private property that is not posted with signs or fenced, or is only sparsely posted with signs or fenced, and you refuse to leave the property when asked to do so by the property owner, you can be cited for trespass.