One thing you might never expect to witness is the Marlboro man on a craggy mountain top, making a tearful call to his mum because his knee is making a funny clicking sound and his sheep dog's got sore paws. But this is the modern-day cowboy, and as Ilisa Barbash and Lucien Castaing-Taylor's absorbing new documentary shows, they're a vanishing breed.
Sweetgrass, which is out here at the end of April, follows a small group of Montana herders and several thousand sheep across the staggeringly dramatic and bleak Beartooth mountains (and yes, the name is no accident). As it turned out, it was the last time this particular group would make the journey, and the movie, while peppered with the occasional exciting outburst — a bear sighting, a weepy phonecall, a tired tirade against all those "cocksucking" sheep — has a quiet, elegiac feel.
There are some incredibly powerful scenes, sheep being sheared in an airless shed to the soundtrack of "Highway To Hell", a female farmer wordlessly coaxing a mother to step free from the flock and tend to her new lamb, and a grizzled old cowboy contemplating his not-so-bright future. And yes, there are times when, like the sheep, you don't know where you're going or which way is up, but you know somewhere in your bleating heart that you're in safe hands.
Sweetgrass is out on 22 April www.sweetgrassmovie.co.uk