The Sons of Katie Elder is a 1965 John Wayne Western also starring Dean Martin. Also in this are Martha Hyer, Earl Holliman, Paul Fix, George Kennedy, Dennis Hopper, Strother Martin, and Rhys Williams. This is a wonderful Western, with great characters and setting and fine acting.
DVD Talk calls it "a pretty good film". TCM has an overview. Rotten Tomatoes has a critics score of 100%.