70-22-201. Coordinate systems adopted -- designation -- division of state into zones. (1) The North American datum systems of plane coordinates that have been established by the national oceanic and atmospheric administration/national geodetic survey (formerly the United States coast and geodetic survey) or a successor for defining and stating the positions or locations of points on the surface of the earth within the state of Montana are to be known and designated from now on as the "Montana coordinate system NAD 27", the "Montana coordinate system NAD 83", and the "Montana plane coordinate system".

(2) For the purpose of the use of the Montana coordinate system NAD 27, the state is divided into a north zone and a central zone and a south zone as provided in subsections (3) through (5).

(3) The area now included in the following counties shall constitute the north zone: Blaine, Chouteau, Daniels, Flathead, Glacier, Hill, Liberty, Lincoln, Phillips, Pondera, Roosevelt, Sheridan, Teton, Toole, and Valley.

(4) The area now included in the following counties shall constitute the central zone: Cascade, Dawson, Fergus, Garfield, Judith Basin, Lake, Lewis and Clark, McCone, Meagher, Mineral, Missoula, Petroleum, Powell, Prairie, Richland, Sanders, and Wibaux.

(5) The area now included in the following counties shall constitute the south zone: Beaverhead, Big Horn, Broadwater, Carbon, Carter, Custer, Deer Lodge, Fallon, Gallatin, Golden Valley, Granite, Jefferson, Madison, Musselshell, Park, Powder River, Ravalli, Rosebud, Silver Bow, Stillwater, Sweet Grass, Treasure, Wheatland, and Yellowstone.

(6) For the purpose of the use of the Montana coordinate system NAD 83, the state is a single zone.

(7) For the purpose of the use of the Montana plane coordinate system (MTPCS), the most recent system of plane coordinates that has been established by the national geodetic survey (NGS), or a successor, that is based on the North American terrestrial reference frame of 2022 (NATRF2022), or a successor, and the national spatial reference system (NSRS), or a successor, and known as the state plane coordinate system (SPCS), or a successor, for defining and stating the geographic positions or locations of points within the state must be known as the "Montana plane coordinate system".