Plot hole: How did the wolves get across the canyon? Unless they were flying wolves, there's no way they could.
Suggested correction: Just because we don't see how they got across doesn't make it a plot hole. We see next to nothing of the area surrounding the canyon. There could have been a pass or trail in the distance that the wolves used. The characters think they are gradually walking away from where the wolves' den is, so they decide to use a makeshift zipline to get to the other side rather than go back the way they came and risk running into the wolves again.