I can see how he (if drifter) possibly arrived at the bridge, and I agree it's possible he didn't get far in 24 hours. I suppose I just keep wondering about his mindset... was he on a mission to find victims? Did he just happen upon them? I suppose he could have been watching them long enough to know they were there alone, as well as determining the "best area" (quiet & no foot traffic) to commit a crime. As always, it's just a guess on these things. But, for me... this aspect of the crime is more intriguing than analyzing the perps pic over and over and over and...
I'm with you. The logistics of this is what is so intriguing to me. The crime itself doesn't take a lot of time, but traveling in and out of the area that they were found isn't something that can be done in a flash. I would imagine that the drainage ditches are holding water this time of year. There is at least one substantial ditch between the bridge and the spot where they were found. The picture of the suspect on the bridge doesn't show a guy who is muddy or wet. He is also walking to the southeast(opposite side from the crime scene) in that picture, just like the one of Abby. So either that was prior to the crime or he managed to avoid getting wet or muddy.
Also, that bridge can't be walked too quickly. It is in bad condition and I've seen where it is some 850' across. Crossing it at least twice would take time. If he only crossed the bridge once, he either crossed the creek leaving without using the bridge or he left the area using a totally different route than he used to enter.
The topography, the creek, the bridge, the limited access by vehicle, the combination of it being somewhat secluded and at the same time an area that is visited by locals, limited time-frame, etc... It doesn't seem to allow for much middle ground. Either was thoroughly planned by someone who knew the area and the times that he would have to work with OR it was an incredibly unlucky encounter with an opportunistic killer.
My reasoning behind it being one extreme or the other is that if it were planned, it was done so in a manner that allowed for the perp to do this without his vehicle ever being spotted and he was able to control 2 girls over potentially a considerable distance in rough terrain.
On the flip side, if it is totally random and he's just a drifter on foot, he can enter and leave in whatever direction and did not have to backtrack or go to specific point to retrieve a vehicle, bike, or motorcycle.
It seems there are two major scenarios that lead in opposite directions. Of course, there is a ton of info we aren't privy to.