Every winter, the Bakhtiari people of western Iran make a treacherous 200-mile journey over the forbidding Zagros Mountains, with their livestock and possessions in tow. This fascinating documentary, narrated by James Mason, trails these hearty tribesmen on their epic, cross-alpine migration.

Shot in 1975, this incredible film brings us into the timeless world of the nomadic Babadi clan, who, along with 500,000 of their Persian brethren, make an annual trek to the greener pastures waiting on the other side of the Zagros, a range equivalent in scale to the Swiss Alps. What makes this film structurally unique from the equally riveting 1925 documentary “Grass,” about a similar, fate-filled Bakhtiari odyssey, is the presence of elder leader Jafar Qoli, who shares with the crew his thoughts, worries, and the history of his clan, an intimate narration rendered in English by the great James Mason.