Advertised as a Horror Western this one skates the limits a little bit. It is very brutal (there is a disemboweling scene I will never shake the memory of) but all the antagonists here are humans. Savage humans, but humans. If anything, this is a horror movie in the way those old Cannibal (Ferox, Holocaust, etc.) movies were. Here, you have Kurt Russell as a Sheriff in a town that is pretty damn near empty anyway. When a local gets abducted by a particularly rough local Indian tribe, Russell gathers up a posse and goes to find them.
The action is very intense in this and I was never really sure who would live from one minute to the next. As far as that goes, it is almost as tense as Green Room. While some of you may argue it isn't really a horror movie, I would say there is enough horrific content for it to qualify. If you liked Russell's turn in Hateful Eight, you should definitely check this out (he's even still sporting the same facial hair). I imagine this one might be a jagged pill for those sensitive to the portrayal of Native Americans in films. While the movie tries to distance regular natives from the villains here, it is still a tad uncomfortable.
Also also, everyone in this movie is pretty damn great. Sid Haig and David Arquette open the film. Richard Jenkins, Jack from Lost and Patrick Wilson are Russell's posse. Everyone is bringing their A-game so I would suggest seeking it out.