Explored in from the end of Field Pond Rd off Rt 20 in Weston and stayed to the right to get to the reservoir.
There were a few rock piles that did not look ceremonial but then I went along the slopes to the west (approximately where the red circle is) and saw a small pile that might have been part of an alignment:
This is a view back downhill. The reservoir is to the upper left. A little further west along the same slope was a large pile:
Again, the reservoir is to the upper left starting near the center of the picture. Since this is about the only interesting pile I saw today, let me add another picture of it:Then I had a bit of trouble finding my way back to my car - in the gray weather. All in all I found rock piles at several other places in there but they all seemed to be non-ceremonial and trashy. Some near the reservoir. Some near a hole near the "golf course". Some near a swamp and near some small terraces, entered by passing between two pillars of cemented cobbles.