From 1913 to 1993, Montana had two congressional districts. From 1913 to 1919, those seats were elected statewide At-large on a general ticket. After 1919, however, the state was divided into geographical districts, with the 1st district covering the western part of the state, including Missoula, Great Falls, Butte, and Helena.
After 1993, the second seat was eliminated and the remaining seat was elected at-large.
List of members representing the district
- Martis, Kenneth C. (1989). The Historical Atlas of Political Parties in the United States Congress. New York: Macmillan Publishing Company.
- Martis, Kenneth C. (1982). The Historical Atlas of United States Congressional Districts. New York: Macmillan Publishing Company.
- Congressional Biographical Directory of the United States 1774–present