Grass: A Nation's Battle for Life is a 1925 documentary film[1] that follows a branch of the Bakhtiari tribe of Lurs in Persia as they and their herds make their seasonal journey to better pastures.

The film highlights the extreme hardships faced by nomadic peoples, as well as the bravery and ingenuity of the Bakhtiari on their migration in search of grass, which meant abundant seasonal pasture for their animals.

The film then follows Haidar Khan as he leads 50,000 of his people and countless animals on a harrowing trek across the Karun River and over Zard Kuh, a subrange of the Zagros Mountains.

[12] The Explorers Journal reported: "It is Mr. Cooper's happy achievement to have portrayed poignantly and comprehensively the drama of a people in their primitive struggle with inexorable forces of nature.

[14] In 1947, Merian C. Cooper sought to remake Grass, which he called a "damned half picture," and he said: "One man and one woman, and their children, will exemplify for the audience the whole of this struggle for survival which breeds a race that is proud and strong, rugged individuals all, meeting bravely the moods of natural forces seemingly bent upon their destruction.

"[15] Ernest B. Schoedsack told him to forget the idea because his Persian friends had informed him that a rail line now ran through the country, and much of the Bakhtiari's trek was now performed using cars and trucks.

[19] In 2009, author Bahman Maghsoudlou published a book titled Grass: Untold Stories that includes background information and historical references related to the making of the film.