Montana State Senate seat · lines in effect since 2024
Montana Senate District 42
A district of about 21,000 people, 43% of adults with a bachelor's degree. It votes R+11.8 relative to the nation for president.
Where it sits among all 50 seats
Every Montana State Senate seat by partisan lean, from most Democratic to most Republican. Lean is the seat's presidential vote on current lines, relative to the nation.
Democratic
Source: 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Every race on these lines
Results recomputed from precinct returns as if today's boundaries had always existed, so years compare like for like.
| 2016 | 2018 | 2020 | 2026 | |
|---|---|---|---|---|
| U.S. Senate | No race | D+12.4 | R+3.3 | No race |
| Governor | D+18.4 | No race | No race | No race |
| Montana State Senate | No race | No race | No race | D+1.1 |
Outlined: the race for this seat itselfBlank: no race that year
Source: 99chambers results archive: precinct results allocated to current lines; 2026: Montana Secretary of StateUpdated Nov 7, 2026, 3:01 PM ET
Who lives here, compared
Grey bars show the spread of all 50 seats. Small marks are other seats in Montana. The black marker is District 42.
Higher than 76% of seats.
Lower than 65% of seats.
Higher than 73% of seats.
Lower than 55% of seats.
Higher than 53% of seats.
Denser than 53% of seats.
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current linesUpdated Oct 13, 2026, 5:06 AM ET
Seats most like this one
Nearest seats on demographics, density and lean. 1 of the 4 flipped this year.
District 4538% college gradsR+19.3Not up in 2026District 29
47% college gradsD+2.6Flipped DDistrict 25
38% college gradsR+24.1Held RDistrict 12
33% college gradsR+14.7Held R
Source: Census Bureau, American Community Survey 2020–2024 5-year estimates, allocated to current lines; 99chambers: 2024 and 2020 presidential results on current lines, relative to the nation (2024 weighted 3:1)Updated Oct 16, 2026, 5:19 AM ET
Who has held it
These lines took effect in 2024.
- Mary Ann Dunwell (D)
2027– · Won 2026 by 1.1
Source: Past results: 99chambers results archive (MEDSL, Klarner, state election offices)