It's unlikely it was because of a call of nature, because he took lunch with him. As the result of fishing, I discovered the bloodhound trail leads only from the camp to his candy and chip wrappers, and mess kit. It doesn't lead anywhere else. That's not good, and indicates someone else is involved, since a 12y/o can't cover a scent trail. I wonder how far the roads are from this site?
Thanks. Doesn't sound good that the scent trail disappears, but I'm not a tracker. I've only backpacked in two areas of the Blue Ridge Parkway. Both were close to roads -- but they weren't all in common use, and the terrain and vegetation could be disorienting.