I need help identifying a movie a saw a long time ago (think +10 years but the movie wasn't recent anyway so I don't know exactly how old).

It's this group of friends who trespass on some rancher's property. One of them starts to turn into a monster, disfigured face. I remember one scene very clearly where one of the friends asks him something like "why are you so upset" or something like that and the disfigured guy replies with "Take a wild guess".