Under state law, it is illegal to remove or deface a lawfully placed political advertisement, including yard signs or billboards, without authorization. Removing or defacing a lawfully placed political advertisement may be prosecuted as a misdemeanor, punishable by imprisonment in county jail for up to 90 days and a fine of up to $1,000.
Rules adopted by the Washington State Department of Transportation regulate temporary political signs located along primary system highways, for example, on private property, or outside of incorporated cities or towns or commercial or industrial areas. These signs must be removed within ten days after an election, except signs for a candidate who is successful in a primary may remain up until ten days after the general election.
Political advertising is not lawfully placed if it remains in place past any deadline for removal provided by law.