I'm guessing here, but could it be The Devil's Prey from 2001? The movie has a group of teens fleeing murderous Satanists who prowl raves looking for victims, a wounded woman on the roadside, a town called Howards Point, a helpful Reverend, and a doubting sheriff.
Tell me where the Blood Red River runs/ From my back door to the rising sun/ On again away till dawn/ Never straight and way too long