I asked a Port of Portland LEO if it was okay to concealed carry in the airport, and he said it was fine. He explained that the port used to have some rule against it but did away with that years ago. He said if someone concealed carried in the airport (and had their permit) he wouldn't even know what to charge them with. He said it's OK. I did double check, there is no sign prohibiting guns at the entrances. Needless to say, this is all on the outside of the TSA security checkpoint. An old friend of mine found out the hard way TSA has no sense of humor about guns. He forgot he was carrying. It was an expensive mistake.