From Roger Corman's Filmgroup, it's BEAST FROM HAUNTED CAVE (1959), directed by Monte Hellman (what a name!) and starring Michael Forest, Frank Wolff, Sheila Noonan, Wally Campo and Richard Sinatra.

Have you ever wondered what KEY LARGO would be like, but in South Dakota and with a monster? Better strap in then!

Context setting 00:00; Synopsis 20:56; Discussion 31:12; Ranking 46:02