If a signature envelope containing an absentee ballot has been deposited unopened in the ballot box and the envelope has not been marked rejected, the signature envelope must be processed as provided in 13-13-241.
Opening Of Signature Envelopes After Deposit
Mont. Code Ann. § 13-13-244, under Procedure for Electors Absent From the Polling Place.
Mont. Code Ann. § 13-13-244