I have not seen this film!  But listen carefully to the dialog which begins the trailer:

Blond-Haired Leading Man #1:  “There are 2 forms of life fighting for survival out here in this valley and only one of them can win.”

Grim-Faced Man #2:  “I’ll talk to the girls in the morning.”

Blond-Haired Leading Man #1:  “The girls?”

Grim-Faced Man #2:  “Yes.  They should bear children as soon as possible.”