Section 270. Official map, establishment

The town board may establish an
  official map of that  part  of  the  town  outside  the  limits  of  any
  incorporated  city  or  village  showing the streets, highways and parks
  theretofore laid out,  adopted  and  established  by  law  and  drainage
  systems  may  also  be  shown  on  such map. Such map shall be final and
  conclusive with respect  to  the  location  and  width  of  streets  and
  highways,  drainage  systems  and  the  location of parks shown thereon.
  Such official map is hereby declared to be established to  conserve  and
  protect  the  public  health,  safety  and general welfare. The clerk of
  every town which has established such an official map shall  immediately
  file  a  certificate  of  that  fact  with the clerk or registrar of the
  county in which said town is located.