My story is set in the early 1990s, and it's about various races of immortal humanoid mythical creatures living amongst humanity in secret. The main setting is a town in America that's been around for hundreds of years. It's one of various immortal "sanctuary towns" in the world, places populated exclusively by immortals and the humans in the know about them. While immortals frequently live in secret within human societies, sanctuary towns serve several purposes:
1: They provide immortals who can't pass for human with a place to live without having to spend their lives hiding in caves.
2: They provide immortal parents with a place to raise their children without their immortality raising massive eyebrows among humans wondering why that couple barely looks 10 years older than their teenage son.
3: They just generally allow immortals to openly be themselves without having to worry about anyone seeing them use their powers.
4: It allows the town to be built with immortal abilities and limitations in mind, such as, say, an underground network of tunnels connecting various buildings together so that the vampires who aren't strong enough to resist sunlight can get to certain places in town during the daytime.
This particular sanctuary town, located somewhere in the eastern United States, is run by the Drake Clan, a centuries-old alliance of vampires and werewolves, with other immortal species as minority members of the clan. I mention this because vampires and werewolves each have an ability that I suspect people might want to know about and factor into their answers: werewolves have superhuman senses of hearing and smell, and vampires have the ability to control the minds of any human they make eye contact with (as long as they aren't exposed to sunlight).
With that being established, here's the problem: in order for a sanctuary town to exist, it has to be able to prevent anyone who doesn't know the secret from getting into the town, because merely entering the town would likely cause you to become aware of the existence of immortals within minutes, if not by seeing one directly, then by hearing people casually talking about them. Sure, letting some people in (while temporarily covering up anything supernatural) will be inevitable, especially when the government is involved, but keeping this to a minimum is necessary in order for the town to serve its intended purpose. So the town has to have some kind of reasonable justification for why it's so selective about who is allowed in the town limits. Key word being "reasonable". They have to have a cover story that most people will buy without batting an eye at it.
How does this sanctuary town contextualize the act of almost completely keeping outsiders out so that outsiders consider this completely normal?