The Beast of Hollow Mountain is a 1956 film about an American cowboy living in Mexico who discovers his missing cattle are being preyed upon by dinosaurs. The first film to show dinosaurs and cowboys in the same picture, it is notable for being based on a story idea by special effects innovator Willis O'Brien. It starred Guy Madison and Patricia Medina, and was produced/ co-directed by Edward Nassour. | Horror, Sci-Fi and Fantasy