We are east of the brook in the Ohlin Conservation Land. Bower's brook is in the background.And here is a trench in the side of a hill with a long rock pile, broken into two pieces to the left. It looks like they took away the sand and left the cobbles behind. This is a typical pattern for sand and gravel quarrying. But then, out here in places like Harvard, MA you are never sure even with the most mundane earthmoving.