BG sure wasn't worried about trespassing on private property out in the woodsy area, where people will run you off. He wasn't concerned about barking dogs. So, he is locally connected to this area.
The girls had been on the trail for an hour before that shot of Abby was taken. It didn't take them an hour to cross that bridge. Likely, they walked the trails first, then went to the bridge. It is also making sense that they crossed paths with him on the trail, thought him odd and that is why they photographed him on the bridge. As in, "ut - oh. Is that that weirdo coming towards us?" They stepped aside onto a platform to let him pass. Or, maybe that is rail bridge etiquette?
The video posted by some woman up thread is chilling. I am convinced that the girls were taken across the river to Logan's property. I just do not know if they were still alive when they reached the other side.
This guy knows the property lines. He is well aware of the area. And he knows who owns the property all around that area. And he knew that Logan wasn't around and that the southern neighbors weren't either. He knew where to cross the river and that it was out or sight from the bridge and trails. He played there as a kid and was run off the property. A lot. His path was over property owned by the RR, which had no agents in the area to make a complaint, two parcels of private property with property lines in the middle of a river which has a sandbar and fronted by a cemetery, which is public although privately owned. He knows how to get on someone else's property fast when confronted. He grew up there. He is a local.