Yeah, that's how it is in AL as well. I joke that my TX LTC is good in 36 states and I know how to carry without getting arrested in 3 of them.
The "places off limits even with a permit" section of handgunlaw.us is always interesting. Signage requirements are just the tip of the iceberg. There's absolutely no consistency between states, even 'gun friendly' states. In some places the premises of a prohibited area is just the building, in others it's all real-estate sometimes including the parking lot. Some places you can legally carry at a protest (i.e. Garrett Foster) in others it's explicitly prohibited. Same for sporting events, polling places, etc.