When a real estate mortgage confers a power of sale, either upon the mortgagee or any other person, to be executed after a breach of the obligation for which the mortgage is a security, either an action may be maintained under this part to foreclose or proceedings may be had under the provisions of the mortgage.
Power Of Sale
Mont. Code Ann. § 71-1-223, under Mortgages of Real Property.
Mont. Code Ann. § 71-1-223