Estabrook Woods, Concord - an(other) broad brush description of rock pile sites

Let me try again with that Estabrook Map:

Here is a map of Estabrook Woods with blue outlines showing areas with one or more clusters of rock piles. In a minute we'll look at some pictures from the area above "Farmer's Cliff" on the map and, in particular, the rock piles near the Boaz Brown cellar hole.

One notices a swath of sites at the southern end of the woods and a few more at the northern end. I have not looked too carefully in the area west of "Corly Pate Hill" and I know there were a few piles and split wedged rocks over near Middlesex school (where the topo line wiggle) but those piles may be gone by this stage of the school's expansion. I believe this site distribution is well correlated to brook access and water sources. Take a close look: The southern sites, except at Punkatasset, are at the top of brooks flowing south. The northern sites - at the north end of Estabrook Rd (Kibbe's Cellar hole) and the north end of Two Rod road (Stearns Str in Carlisle) - have sites near wetlands and brooks that flow north into Spencer Brook before heading south (past lots of other sites in Acton and Carlisle).

The exceptions test the rule: Punkatasset has piles on its northern slope, and Annursnac Hill, the other major hill north of the rive, has them on its southern slope. I imagine a slightly different reason explains the location of these sites on hillsides rather than at brook sources. Also testing the rule: the blank space west of Corly Pate Hill has no water sources, no brooks leading up to it, and is correspondingly blank. So look: they paddled up the river, as far as they could, sought out the highest headwaters (and hills overlooking them) and constructed rock piles.