Oriah, Do you happen to know how populated the area is? I looked at Google maps and it appears that the residences are spaced some distance apart (of course I really couldn't tell that much from the satellite view of the Bobo property). Are maps of the area published out there somewhere on the web or did you get them from another source? The reason I ask is because I think you are definitely on to something there. I've thought the same thing for some time but didn't know of a resource for any off road maps of the area. This is my theory ... if someone were going to hide a body, even as small as Holly is, carrying dead weight a good distance wouldn't be easy. So, it would be feasible that someone could have transported her part of the way via 4 wheeler, then carried her body off trail from there to hide it deeper into the woods. Makes sense to me.
I'm using a different map than this- but the area is available here (for a free trial period anyway...Mods, does that count as a free site or a paid site?? Help!) :
http://www.topozone.com/map.asp?lon=-88.2200413&lat=35.790343&datum=nad83
Or if you have a GPS and an updated USGS map, you can plug in the coordinates of the Bobo residence, and start looking at the access to trails there.
HTH.