More scenes form Hopkinton - Echo Lake

Walked north from the bike trail and crossed a dirt road then stepped across the western branch of the (upper) Charles River and proceeded up and then down and then north up a long ridge. [This brings us to ~B or somewhere north of B on this map.] I got bored climbing the ridge and turned east back towards the wetter area (of the Charles?) and immediately was rewarded with a peculiar rock pile site.

Located in a gully, this was a bit like a marker pile site:

In one place SB said: "look, 3 in a row":

But I think this is misleading. What came through to me, more clearly, was the sense of herringbone arrangements for the piles: 

The only other place I know that has this kind of herringbone is near Gibbs Mountain in Sudbury/Framingham as mentioned here. I am not sure it is the same thing.

 You can see the herringbone effect here, as we look up the gully.

This "gully" is a place that might flow with water at certain times.
Looking down at the site:

The fun continued above it, as we tended back towards the higher ground:

and then swung back towards the lower ground:

Dipping back down to the wetter areas, here is another site.

I do not know exactly where these places are- a bit south of Echo Lake. As I said earlier: it really does not matter - it is all one huge rock pile region. You can find sites anywhere in those woods. Here the LFH discuss a structure:

There is so much in there:

Then we walked back out to the car. Our exploration continues "on the flip side".