Two map views of 6071 Lower York Road. One from Bing and another from Google. You can see the concrete pile in the lower right corner of the large field where the common grave was found, and then to the Northwest a smaller rectangular field on the side of the hill. Also, on Bing map you can see additional piles of concrete around the perimeter of the "upper" field. Posted before that IMO this would be an ideal spot to hide a grave(s). With the road leading up to it from the lower field, would certainly be able to get a large piece of equipment up there. I think this is the field where they found JTP?
It was also noted earlier that maps prior to 2005 (when CD's family bought property) there was no road to the "upper" field, and no concrete piles up there either. Will try to find this map in earlier posts.
https://binged.it/2tRoFd2
https://goo.gl/maps/iLAEUEP6EE72