This movie is sometimes categorized as sci-fi, but it really isn't. Beast of Hollow Mountain (BoHM) is a monster movie. There is no "science" to explain the existence of the beast. Instead, as was typical of the monster genre, he simply exists, and the characters must deal with him. A dinosaur monster movie and western hero / romance movie hybrid, is an odd mix. Even though it doesn't really qualify as sci-fi, it's included here only because the title shows up in other people's lists of 50s sci-fi.
Very Quick Plot Synopsis
An rancher in Mexico is losing cattle. He suspects a rival rancher who is trying to put him out of business. The locals say it is a "beast" which comes out of Hollow Mountain whenever the swamps surrounding it dry out enough. A love triangle develops between the two rival ranchers and a pretty seniorita. The feud between the two ranchers is interrupted when the beast, a T-Rex, appears. The T-Rex first stampedes the cattle, threatening the village. It then tries to get the seniorita and a little boy. It chases the two ranchers into a cave, finally getting the sinister rancher. The good rancher leads the beast towards the swamp and lures it in. The beast sinks in the quicksand. All is well and the triangle resolved. The end.
Why is this movie fun?
As a simple monster film, BoHM has its own quirky appeal. Dinosaur vs cowboy! The pace in the last 20 minutes of the movie is brisk. This last part has much affinity to more sci-fi movies like Beast from 20,000 Fathoms ('53), It Came From Beneath The Sea ('55), Revenge of the Creature ('55), The Snow Creature, ('54) etc. Monsters running amok among people. This may be why BoHM gets lumped into the sci-fi genre. Still, the animation has its amusing moments to watch: T-Rex carrying off a steer in his mouth, and that crazy flailing tongue!
Cold War Angle
As a hybrid of the western genre (which has no Cold War baggage) and the monster movie (which also has no Cold War heritage), there's no allegories to commies or nukes.
Timeless Dinosaurs -- True to the monster genre, the beast simply exists. Given the narrator's talk of old legends, that T-Rex had lived in that mountain for centuries. Not a self-sustaining population of Ts, just this one, who can apparently go without food for years at a time. All this points ton almost mystic view of dinosaurs -- a creature beyond mere biology.
Budget Beast -- The stop-motion animation of the beast was passable. It was certainly not up to Harryhausen standards. While not as smooth, it wasn't too bad. What was more fun, was the big rubber T pants. There were two or three scenes where the monster's approach was shown with an actor taking big steps in a waist-down costume of T-Rex legs. Given how much prop recycling has gone on already in B-movies, it will be interesting to see if the rubber T pants show up in some other low budget film.
Typical B Western -- The western tale portion of this hybrid had all the usual ingredients. There was a clear good guy and clearly bad bad guy. There was a knock-down fist fight between them. There a full-gallop scene, a stampede and, of course, a beautiful young woman for the good guy and bad guy to fight over.
Remake -- As obtuse as a dinosaur & cowboy movie might sound, it was apparently credible enough to be done again in 1969. The Valley of Gwangi is a more complex tale and a better done film. Of course, coming 13 years later gives people some time to polish the brass.
Bottom line? BoHM really doesn't belong in sci-fi movie lists. It really offers none of those thoughtful moments or allegories or even social commentary. It's just plain old entertainment. If you like old westerns, and like rampaging dinosaur movies, BoHM is just the hybrid for you.