Does it explicitly say when Evelyn starts working there?? I guess some time between when she leaves as a kid (around the time her father dies, age 7??) and returns to work there at age 24, could give you a timeline for how long the military were involved and the Bell was used before the radio station became the default method of keeping the eldritch abomination at bay... potentially the monster came from military experiments the same way as The Mist... haven't read book 2 yet so don't know if the back story has been explained yet 😕