I saw the 1966 Western The Professionals. I have seen so many movies from the 1960s but I don't know how I missed this one. This is available on Netflix. Burt Lancaster', Lee Marvin and Other well known actors made a good combination even though Burt Lancaster' and the marvin couldn't stand each other due to Lee Marvin being a drunk in Las Vegas all the time off the set. I am including the movie trailer in the comments. This movie was filmed in California by the Death Valley and Coachella Valley. Parts were also filmed in Nevada.