Willis O'Brien's Gwangi was an epic movie that was never completed. King Kong's visual effects wizard made elaborate plans for a spectacular motion picture project. Gwangi combined elements of The Lost World with cowboys, rodeos, and Western themes. Like all of O'Brien's projects, it was meticulously preplanned. Particular scrutiny was placed on how each scene would be brought to the screen. The Assistant Director's Breakdown Sheets are valuable clues to the epic that Willis O'Brien's Gwangi could have been. They detail characters, costumes, stunt doubles, extras, horses, dummy horses, props and sets. They describe process shots, glass paintings, miniatures and animation, as well as full size mechanical effects. Scanned from the original documents they are presented "as is" in full color, complete with the discoloration and stains that attest to their sixty plus years. The originals are in pencil, some of them in colored pencil. The different colors designate the various processes that had to come together to create a finished frame of film.