“There is a lot of work to be done in the summer,” says Tibetan nomad Yama in Summer Pasture, a documentary directed by Lynn True and Nelson Walker (working with co-director Tsering Perlo). The film bears witness to that fact. Up at 4 a.m., Yama collects yak dung, wrangles pots and pans in the yurt, and milks the livestock—at one point in the midst of a high-grasslands hailstorm. Her herder husband, Locho, stands by, speaking of their courtship and showing the camera his caterpillar-fungus stash (he claims not to understand whether the Chinese use it to make medicine or poison, only that it’s worth more than gold). Life in the bustling Dzachukha county seat, where Locho haggles for supplies and visits the doctor on his wife’s behalf, provides a constant point of comparison; Locho estimates that four to five neighboring families relocate there each year. Wanting to send their daughter to school, and increasingly hemmed in by local policies (the film isn’t expressly political, but Yama does discuss China’s per-couple child maximum, and Locho attends a community meeting where he’s told it’s illegal to assemble in groups larger than four), they face doing the same, though not without trepidation. Yama explains that she and her husband, both illiterate, “were like yaks” during a pilgrimage to Lhasa. Summer Pasture is remarkable not merely for documenting the disappearing way of life, but for registering the depth of Yama and Locho’s uncertainty about moving on from it.