I've considered an entry from this direction. The abandoned railroad bed leads around to 200, right between Pine Grove Missionary Baptist Church, and PTI Machining. So I've thought maybe he could have parked at either of those places, and under cover of the treeline, via that abandoned railroad line, made his way to the bridge area, and back out again.
I've considered he may have parked upstream at near where google maps shows the Deer Creek Valley Rural Historic District, as there is a large open area where one could park and be relatively unseen.
I've also considered he may have parked at the pull off at the Old Royster Ford and Carroll County Bridge No. 121.
He could have been picked up at any of the aforementioned areas.
I've also considered that he may have been parked under the bridge, on the private drive, with the intent to get the girls in the vehicle some how, but they ran when they saw what his intent was. I kind of doubt this, as the car would likely have been seen by someone that day.
With all that being said, parking at the rear of that cemetery puts him right smack dab in the area of the CS, bridge, and trails. Easy in, easy out.
MOO