Carol, have you tried getting their death certificates ? You may get lucky and they will have the parents names on them, depends on who gave the information for the records and how much they knew about them. Might be too early for death certificates in Montana but they would have a record of his death. How about naturalization records for Carl Muller ? Marriage record for 2nd marriage in MN might have parents names. Have you written the church they attended ? there might be some record of baptizmals for the children, sometimes they put the parents birth place. Just suggestions. Cidney