What is the town in which US troops were sent to fight rumored paranormal entities?

Question

I watched a a couple of videos related to this exact event but payed little mind, one of the sources was from television the other social media. This even consisted of United States troops evacuating a small town in which many people would go missing and others would claim paranormal presence. The event takes place around the time of the Vietnam war and I cannot remember if this is actually a thing, a over dramatized evacuation, or is a real occurrence I can no longer discover. The original sources showed war footage of troops filming trees with inscriptions and fire fight taking place in the dark.