The Valley of Gwangi

“Cowboys Battle Monsters in the Lost World of Forbidden Valley.”

Tuck Kirby (James Franciscus) needs money to keep T.J. Breckenridge's (Gila Golan) struggling wild west show from going under in Mexico. Then a tiny prehistoric horse turns up, and it points the cowboys toward the Forbidden Valley, where living dinosaurs are said to roam. Jim O'Connolly sends them across the desert, and the valley's rock walls rise ahead of their horses.