SWEETGRASS is one of those unique documentaries that is goes beyond simply being a doc and becomes an art film in itself. This is not a film for everyone. There is very little dialogue in the film and almost no music. Three is no voiceover and there are no title cards to explain what's going on to the audience. It's 100 minutes of sheep farming, much of it in real time.
Nonetheless, it is still a very interesting film. There's something hypnotic about seeing the sheep. The pacing though reminds me a bit of some of Andy Warhol's deliberately real-time films. Even if you have the patience to sit through that (and I do), there are still problems with the film. As an animal lover, there were several moments that were disturbing to me, even though the film probably accurately portrays sheep farming. (They also never show their slaughter, just their shearing, but there is always that undercurrent of knowing where they will end up.)
The biggest problem comes late in the film when it finally becomes about the people and not the sheep. One of the farmers has a mental breakdown. The problem is that we were never properly introduced to this character, he just comes out of nowhere, so it's tough to care about - or even follow - what's going on.
Nonetheless I would recommend it, but only to the right audience. If it sounds interesting to you, that might be you!