That's a good point. I'm going to assume, without any other information, that she was killed where she was found. Hasn't it been noted that the campsite they were at was highly populated? If so, wouldn't it be safe to assume that someone being killed out in the open would be heard?
Maybe so but you could also ask. In a highly populated campground, wouldn't someone dragging a body 900 feet from the road be seen? I think it likely their tent had been pitched where her body was found. They had a continuation of the fight in the restaurant and he beat her to death, packed up and left her there. Even some serial killers have left their victims covered out of some sense remorse but whomever killed Gabby just left her there in the open exposed to the elements. JMO but to me this shows just how bad their relationship had become and how little he cared about her at the end.