70-22-205. Technical description of zones. For the purposes of more precisely defining the Montana coordinate systems NAD 27, NAD 83, and MTPCS, the following description by the national oceanic and atmospheric administration/national geodetic survey (formerly the United States coast and geodetic survey) is adopted:
(1) The Montana coordinate system NAD 27, north zone, is a Lambert conformal projection of the Clarke spheroid of 1866, having standard parallels at north latitudes 47° 51′ and 48° 43′, along which parallels the scale must be exact. The origin of coordinates is at the intersection of the meridian 109° 30′ west of Greenwich and the parallel 47° 00′ north latitude. This origin is given the coordinates: x = 2,000,000 feet and y = 0 feet.
(2) The Montana coordinate system NAD 27, central zone, is a Lambert conformal projection of the Clarke spheroid of 1866, having standard parallels at north latitudes 46° 27′ and 47° 53′, along which parallels the scale must be exact. The origin of coordinates is at the intersection of the meridian 109° 30′ west of Greenwich and the parallel 45° 50′ north latitude. This origin is given the coordinates: x = 2,000,000 feet and y = 0 feet.
(3) The Montana coordinate system NAD 27, south zone, is a Lambert conformal projection of the Clarke spheroid of 1866, having standard parallels at north latitudes 44° 52′ and 46° 24′, along which parallels the scale must be exact. The origin of coordinates is at the intersection of the meridian 109° 30′ west of Greenwich and the parallel 44° 00′ north latitude. This origin is given the coordinates: x = 2,000,000 feet and y = 0 feet.
(4) The Montana coordinate system NAD 83 is a Lambert conformal conic projection of the GRS 80 (Geodetic Reference System 1980) ellipsoid, having standard parallels of north latitudes 45° 00′ and 49° 00′, along which parallels the scale must be exact. The origin of coordinates is at the intersection of the meridian 109° 30′ west of Greenwich and the parallel 44° 15′ north latitude. This origin is given the coordinates: x = 600,000 meters and y = 0 meters.
(5) The Montana plane coordinate system must be the state plane coordinate system of 2022 (SPCS2022) or its most recent successor as defined by the national geodetic survey or its successor agency.