In 2003, a last herd of sheep made its way through Montana’s Absaroka-Beartooth mountains, taking over three months and covering some 150 miles. That journey is documented in Sweetgrass, in images ranging from magnificent to stark, most often observing sheep in motion — trekking along dirt roads, up and down mountainsides, through densely green forest trails or snowy fields. Watching these creatures from overhead and from behind, from long distances or right up in their baaing faces, the film doesn’t anthropomorphize or otherwise imagine emotional lives for the sheep. Instead, it contemplates the simultaneous aspects of this journey — both timeless and now, after 2003, ended.

It’s a full 18 minutes before you even hear spoken words in Ilisa Barbash and Lucien Castaing-Taylor’s remarkable film (it is now open at New York’s Film Forum, and the filmmakers will be on hand to speak on 8 and 9 January). Here a rancher is speaking to a just born lamb, informing “junior” that they’ll have to find him some milk, as his own mother isn’t providing any. As he pushes another nursing ewe up against the walls of her pen and pushes her baby away, the man’s gestures bespeak both the urgency and the familiarity of the situation. He moves deftly and aggressively, trying to push one natural process to override another, a drama that lasts but a minute or so, before the film moves on to another scene, without revealing whether or not the lamb survives.

It’s only one moment in a long story, of course (the filmmakers actually shot for three years). Before this in-the-barn moment, the film has observed sheep outside — some 3,000 of them moving in long lines like ants, pushing one another aside to grab at grainy mush or hay laid out on frozen earth. They teem, they crowd, they look directly into the camera, their expressions odd and poignant, not conscious, maybe just complacent. Or maybe, grouped together and headed to a single, knowable end, just sheep, thoughtless and symbolic.

As a parable, the story of sheep is unsubtle. As poetry, however, it is stunning. The lack of language encourages your appreciation of the human loneliness and difficulty of living among sheep. A young herder and the older wrangler John Ahern herd the sheep over their long route, enjoying the big sky and long views, then enduring hard weather and physical pain. As the young man reveals during a phone call to his mother late in the film, “This is bullshit, mom. My dog’s so sore-footed, he can’t walk.” On top of that, he has a problem with his own knee (it’s clicking), and he’s wondering just why he’s doing this, again. “It’s impossible,” he goes on as the camera pans from him over the gorgeous vista of mountains to his right. “It’s so goddamn rough, I mean, you kill a horse. My horse is ribs and bones. I’m riding the shit out of him.” When his phone runs out of battery, he quickly bids his mother goodbye, then the camera follows him as he walks away, calling and then affectionately greeting his dog, “You dumb cripple.”

The young man’s emotional expressiveness — alone on the mountain — is unusual in the film, but the basic feeling (“I’d rather enjoy these mountains than hate ’em”) is neither devastating nor strange. A sense of faith, persistence and extraordinary patience are prerequisites for herding sheep, whether the job is handed down in families (as it is so often), refuge or adventure. The herders spend most of their days apart, that is, on opposite sides of their herd, atop their horses, directing dogs and smiling occasionally at young riders. John reminds one girl to say her prayers at night, as the low-angle frame shows only a horse’s silhouette against a darkening sky, the individuals and their tents less compelling here than their vast, lovely, and constantly daunting surroundings.

If the film doesn’t pretend such natural beauty is only that, neither does it make a familiar case, whether nostalgic or to protect the environment. Rather, it shows that this hard life has effects, good and bad, that it presses workers to their edges and also helps them to discover themselves as well as the world around them. Again and again, the sheep are alternately incredible to see and plainly unpleasant to live with: John saddles his horse in the morning while murmuring, “You got away from the sheep all night, got away from the damn sheep all night. A relief, I imagine.”

But leaving them behind is another issue, complicated in ways at once emotional and philosophical. As John rides away from the herd in a pickup, the driver glances over, toward him and the camera. He asks John what he’s planned for the future. “I don’t know,” John says, not looking at his questioner. “I wasn’t going to worry about it for a week or two.” In the mountains, among the bleating sheep and looming trees, you learn that time is relative.

RATING 10 / 10