Mont. Code Ann. § 32-1-493

Any photostatic or photographic or microfilm reproductions (including enlargements of the latter) of any original records or files of any bank, whether in the form of an entry or entries in a book or any other form of record, shall be admissible in evidence in any court of competent jurisdiction in proof of an act, transaction, occurrence, or event when shown to be made in the regular course of business of the bank. But nothing contained in 32-1-491 through 32-1-495 shall be construed to authorize the use of secondary evidence in administrative or court proceedings when original records are in existence and available for use in accord with the rules of evidence.