Cooper felt that the great adventure of his life had been when, in 1924, he and his two companions accompanied Haidar Khan and his 50,000 Bakhtiari tribesmen and their numberless animals on their long, difficult, heroic and dangerous annual migration -- on foot over frozen mountain passes and across a swollen river on goatskin floats -- over the Zargos Mountains in search of winter pasture. In the 1920s, when Americans lived in a world with radios and airplanes and automobiles, there were still people in the world who lived seemingly as they always had, following their herds on foot across vast open spaces, living in tents and carrying their possessions with them.
Cooper’s film of that trek, “Grass”, released in 1925, had been made under difficult conditions and he had barely had enough film stock to reach the end, and the finished product had been edited for an American audience that might not know what to make of a documentary film of so strange a people and way of life.
A quarter of a century later, the war behind him and with the resources of a modern Hollywood film crew, Cooper wanted to go back and do it right. And so in 1947, he sent a film crew back to Persia, now called Iran, to make a proper record of the migration before this ancient and heroic way of life was washed away by the modern world.
When the crew got there they found there was now a railroad and that the Bakhtiari now used trucks and cars in the migration and the wild, flooded Karun River that tribesmen and their stock had made their way across on inflated goatskins was now spanned by a bridge. The crew came back with nothing to show for their trip. The world that Cooper had seen just a quarter-century earlier had ceased to exist. “For Cooper, the expedition’s failure represented a door that had closed, forever, on one of the great dreams of his life.” Mark Cotta Vaz, Living Dangerously, 339-40.