The elements crucial to any cowboy film are all here: a long trek that pushes the heroes to their limits, perilous shootouts with tragic casualties and a triumphant victory that will forever cement the heroes as the last of their kind.

Sweetgrass follows several modern cowboys as they take their massive flock of sheep through the mountains of Montana to their summer pastures. Along the way they sustain injuries, shoot at bears and use language that would make Mel Gibson blush.

They travel more than 300 kilometres through rugged terrain, and their frustration at some points is very clear.

And yet, somehow the filmmakers edited their documentary to be utterly boring.

The film is visually rich, showing beautiful landscapes and plenty of sheep.

However, the pace becomes painfully slow with some shots lasting for an eternity and showing nothing of interest.

The film is purposely edited to contain these long, slow shots, but this technique will render the film virtually inaccessibly to those with modern, movie-going attention spans.

A complete lack of narration or explanation until the very end leaves the viewer guessing and annoyed. The plot is not difficult to understand, but at some points there is utter confusion and no attempt to clarify what is happening.

There is also no music to accompany the film. This means that apart from the inane drone of hundreds of sheep and some mostly incoherent mumbling from the aged cowboys, many of the long scenes are completely silent.

The film documents a difficult journey, the last of its kind.

However, with such slow editing and without a narrator and a soundtrack, the documentary fails to create excitement about the subject matter or encourage an emotional bond between the viewer and the real-life cowboys on screen.