My thoughts on the possible routes taken.
At 2:07 Abby and Libby were on the bridge and had crossed over the water. Abby is walking in the south/east direction in the snapchat photo.
At some point Abby and Libby reach the end (or close to the end) of the bridge on the south/east side. We know this because of the video stills of the . He is walking towards Libby's camera and towards the south/east end of the bridge.
The billboards that show just the , list the time as the being "last seen" as 2:30pm. This would possibly fit with the video stills.
To go "down the hill" at the south/east end of the bridge and cross the creek to the crime scene is about 450 to 550 feet depending on the exact route.
To go back across the bridge to the north/west end of the bridge, go "down the hill" and to the crime scene is over 2000 feet depending on the exact route.
Both routes will lead to the crime scene but to me the route from the south/east end would be more likely. Seems more isolated at the south/east area after watching all the videos.
Also, the bridge is in disrepair, and crossing all the way back to the north/west end would need to be done slowly and carefully. The bridge is about 850 feet long.
There was another person who said she arrived at the north/west side of the bridge at approx. 3pm. She said she did not see the girls.
Maps of possible routes. (2 different views)
View attachment 111265View attachment 111266
http://heavy.com/news/2017/02/liber...ssing-snapchat-facebook-photos-family-bridge/
http://wane.com/2017/02/24/fbi-expanding-billboards-for-tips-in-indiana-teens-killings/
https://bridgehunter.com/in/carroll/high/#Desc