Mont. Code Ann. § 72-38-906

The following terms or comparable language in the provisions of a trust, unless otherwise limited or modified, must be construed as authorizing any investment or strategy permitted under this part: "investments permissible by law for investment of trust funds", "legal investments", "authorized investments", "using the judgment and care under the circumstances then prevailing that persons of prudence, discretion, and intelligence exercise in the management of their own affairs, not in regard to speculation but in regard to the permanent disposition of their funds, considering the probable income as well as the probable safety of their capital", "prudent man rule", "prudent trustee rule", "prudent person rule", and "prudent investor rule".