Mont. Code Ann. § 70-22-206

Coordinates based on the Montana coordinate systems purporting to define the position of a point on a land boundary may not be presented to be recorded in any public land records or deed records unless the coordinates have been determined with respect to the national spatial reference system (NSRS) at an accuracy consistent with the relative accuracy of the land boundary as presented in the recorded instrument. Public land or deed records presented for recording that purport to define the position of a point on a land boundary based on coordinates from the Montana coordinate systems must contain a statement that identifies the specific realization of the reference frame or datum of the coordinates, including the coordinate epoch date if applicable, along with the type of equipment and methods used to perform the survey and tie it to the NSRS.