A tract or parcel of land that has been shown on municipal maps or plats as being within municipal boundaries but is later found to have been improperly or unofficially annexed is conclusively presumed to be annexed and may be so recorded if municipal taxes have been paid on the tract or parcel without protest for a period of 7 years.
Mont. Code Ann. § 7-2-4331
When land conclusively presumed to be annexed
En
Official source: Montana Code Annotated (Montana Legislature). Reproduced from public-domain Montana statutes; confirm against the official source for the current text. Not legal advice.