There is hereby established within the Township an area which shall be known as the Steep Slope District, in which land development and construction shall be subject to the special regulations contained in this section. The Steep Slope District shall include those portions of the R-1 (one family residence zone), R-2 (one, two and three-family residence zone), R-3 (one, two and three family residence zone including townhouses), R-4 (multi-family residence zone), B-2 (outdoor recreation zone) and Planned Development District, designated on a map entitled "Zoning Map, Township of Weehawken, Hudson County, New Jersey revised through November 1986" which is on file with the Township Clerk and which is hereby adopted by reference.