Mont. Code Ann. § 26-1-623

For the purposes of 26-1-622, any finding, report, or record or certified copy of a finding, report, or record purporting to have been signed by an officer or employee of the United States as described in that section is prima facie considered to have been signed and issued by the officer or employee pursuant to law, and the person signing the finding, report, or record is prima facie considered to have acted within the scope of the officer's or employee's authority. If a copy purports to have been certified by a person authorized by law to certify the finding, report, or record, the certified copy must be prima facie evidence of the person's authority to certify.