2006 New York Code - Maintenance Of Monuments.

 
    § 8. Maintenance of monuments.  The commissioner of transportation, in
  cooperation  with  persons duly authorized by the adjoining state, shall
  cause the monuments erected, or to be  erected,  as  boundaries  of  the
  state, to be maintained, and cause suitable monuments to be set wherever
  such  are  now  lacking  at  the  points  where  such  state boundary is
  intersected by the boundary of any towns or counties of this  state,  or
  by any highway.