Personally this type of film irritates me. Will they be found out will they not? It is very hard to maintain the tension throughout the film. Unfortunately this film does not quite manage it. Leaving me to laugh as the main characters speed away from the ranger (who is in no position to follow immediately), stop to spend five minute disposing of guns, then crash into a log truck only for the ranger to arrive seconds after and tick them off for driving too fast.
Just after the hour mark, the ranger's character has developed to a point at which she can have a scene to herself. I feel this was unnecessary, sitting on the main 2 characters shoulders gives us the tense limited vision holding the suspense. Diverting the attention releases that tension to a degree and the film focus shifts.
The movie defies the usual theory of a defined protagonist and antagonist, as we are debating over calling the first ranger's death an accident or a crime. By the final ten minutes most people will have decided who the bad guy is in the film just in time to have the desired effect at the conclusion. Which I felt was a little bit soft.
Overall the film was not such a bad watch. It had its peaks and troughs, the technique is to sit back and watch, don't try applying your own thoughts or reactions to the characters or you will tear your hair out.