Such bounds shall be of stone, Portland cement or concrete not less than three feet long, two feet of which at least shall be set in the ground, or of stone not less than three feet long with holes drilled therein and filled with lead placed a few inches below the traveled part of the way, or if stone, Portland cement or concrete bounds are impracticable, a heap of stones, a living tree, a permanent rock, or the corner of a building, or such other permanent bounds as said officers may determine.
Massachusetts Legal Code