According to 76-3-103 MCA a subdivision in Montana is defined as a division of land or land so divided that it creates one or more parcels containing less than 160 acres. The title to the parcels may be sold or otherwise transferred and includes any resubdivision and a condominium. The term also means an area, regardless of its size, that provides or will provide multiple spaces for rent or lease on which recreational camping vehicles or mobile homes will be placed.

Both major and minor subdivisions go through a similar review process. Major subdivisions have a few additional requirements including a public hearing, and an environmental assessment. The second notification letters for a major subdivision are sent via certified mail to adjacent landowners and regular mail to agencies by the County Planning Office, whereas the subdivider handles this for a ‘first’ minor subdivision.