With rugged reverence, Sweetgrass depicts the final sheepherder drive into Montana's Beartooth mountains, a saga that begins on farms where sheep are born and shorn, and ends in another cattle pen after an arduous trek across the region's blustery plains and punishing peaks. It's an annual ritual that began in the 19th century, and one positioned by filmmakers Ilisa Barbash and Lucien Castaing-Taylor as a longstanding custom as deeply embedded in the cowboy way as are sheep's innate instincts to bleat, feed, and follow the pack. Man, animal, and earth, all shadowed by the big sky's enormous clouds, are here intertwined in a cyclic ritual, one that expands not only across species but generations as well, as subtly expressed by the sight of aged herder Joe guiding his four-legged flock with the help of his horse-riding daughter and younger son. This symbiotic relationship is filtered not through traditional American West clichés or conveyed with icky romanticism but is depicted as a vanishing example of the world's capacity for both hardness and beauty. Barbash and Castaing-Taylor's realistic treatment lends the footage a tough-mindedness, whether it be the sight of herders pinning sheep's heads between their legs while sheering, clothing a lamb in a dead newborn's wool so that the deceased's mother might accept the new child as its own, or the enormous herd—its myriad moving heads and limbs, as well as its baaing chorus, making the convoy seem like a cohesive living entity—trickling down a mountainside like a river stream. In its starkly beautiful imagery of herders and sheep's kinship with each other and their imposing, hazardous surroundings, Sweetgrass achieves a borderline abstract splendor that's furthered by the directors' avoidance of delving deeply into its human subjects, whose backstories and general circumstances are only alluded to through fly-on-wall scraps. As the migration progresses across the wild Montana landscape (the journey marked by teepee camps, shotgun warning blasts at encroaching bears, and punishing exhaustion and frustration), the focus slowly shifts from sheep to men. It's a change that may lend this nonfiction eulogy a slightly more conventional narrative structure, but courtesy of the film's portrait of life in all its scraggly, majestic glory, depletes not an ounce of its hard-bitten potency.