<Li> Chuck Roberson as Texas Ranger </Li> <Li> Bernard Fox as the Scottish Shepherd </Li> <P> Written as The Million Dollar Kidnapping, which was used as the shooting title, it was filmed from early October to early December 1970, in the Mexican states of Durango and Zacatecas, including scenes shot at the El Saltito waterfall and Sierra De Organos (in the municipality of Sombrerete, Zacatecas). </P> <P> John Wayne's real - life son, Patrick Wayne, portrays James McCandles in the film, while Robert Mitchum's son, Christopher Mitchum plays Michael McCandles . Wayne's youngest son Ethan Wayne is seen as his grandson, Little Jake, in the movie . </P>

Where was the movie big jake filmed at