Montana Title 72. Estates, Trusts, and Fiduciary Relationships § 72-1-301. Notice--method and time of giving

(a) by mailing a copy of the notice at least 14 days before the time set for the hearing by certified mail or ordinary first-class mail addressed to the person being notified at the post-office address given in the person's demand for notice, if any, or at the person's office or place of residence, if known;

(b) by delivering a copy of the notice to the person being notified personally at least 14 days before the time set for the hearing; or

(c) if the address or identity of any person is not known and cannot be ascertained with reasonable diligence, by publishing the notice in a weekly paper once a week for 3 consecutive weeks and, if in a newspaper published more often than once a week, by publishing on at least 3 different days of publication. There must be at least 10 days from the first to the last day of publication, both the first and last day being included.