Rock-on-rock leading down a hillside - Westford/Tyngsborough line

I was exploring and found 2 sites off the end of "Paddock" road, a side branch of Tenney Rd/Westford Rd. See the two small outlines at the top of the map here. Walked it and wanted to climb that small unnamed hill. Saw a rock-on-rock near the summit:When I walked over to this, I saw another rock-on-rock downhill.When I walked down to this, I saw another rock-on-rock downhill.Another view of this interesting shaped rock:And so it continued down the hillside. Here is a view back up the sequence:I do not think these rock-on-rock structures are marking a trail, although it is tempting. When I got near the foot of the hill, I saw three or four more structures, layed out in horizontal direction.
How about this nice one:If these structure define a trail, it is not designed for efficiency to get you from A to B.