Reader Brian M. writes in:
I have a newfound respect for how difficult it is to shoot these things and make it so you can actually see anything. As I said, these are in a section of Petersham that old maps designate as the Indian village. It also features an area that I would call a glacial delta except that it's made of gravel and stones like the ones in the piles.
There are "stonewalls" in the area that may indicate agricultural use in the past. There was a mill in the neighborhood (powered by the east branch of the swift river) that produced barrels. I'd be interested in any thoughts you have on the piles. Some are as long as 30 or 40 feet and maybe 20 feet wide.