Just a little history,
Back in 2004, SeaTac Airport went to the Legislature and asked for restricted access areas to be banned by anyone from carrying. Now, the state law merely duplicates federal law on the subject, so that a state law enforcement officer at Port of Seattle PD can arrest someone on state law grounds. The reason of course was that they couldn't enforce the ban on the books due to preemption.
That law was passed in 1981. Preemption passed in 1983 and 1985.
I will be following up with Port of Seattle on this subject.