Just Before Dawn (1981)
The nightmare has just begun --
A group of city slickers are slowly being massacred by an inbred, deformed country dweller. When some friends enter the woodlands for some rest and relaxation, they foolishly disregard the warnings of the local sheriff and a mad man who cries about demons in the forest. However, they soon regret their decision as a powerful, crazed killer begins stalking and killing them one-by-one for invading "his" woods.