Montana State House District 31

State Legislative District Profile (Lower Chamber)

Overview

District ID
mt-hd-031
State
Montana
Chamber
Lower chamber
District Code
031
Land Area
3,322.3 sq mi
Water Area
181.8 sq mi

Boundary

Boundary of Montana State House District 31

Boundary as GeoJSON

Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.

Counties

CountyOverlapShare of district landShare of county land
Phillips County1639.06 sq mi49.3%31.9%
Valley County984.62 sq mi29.6%20.0%
Roosevelt County565.96 sq mi17.0%24.0%
Blaine County132.70 sq mi4.0%3.1%

Showing all 4 counties

Places

PlaceOverlapShare of district landShare of place land
Lodge Pole CDP13.39 sq mi0.4%100.0%
Zortman CDP3.95 sq mi0.1%100.0%
Frazer CDP1.62 sq mi<0.1%100.0%
Brockton CDP0.99 sq mi<0.1%100.0%
Fort Peck town0.89 sq mi<0.1%100.0%
Wolf Point city0.86 sq mi<0.1%97.2%
Poplar city0.28 sq mi<0.1%100.0%
Landusky CDP0.09 sq mi<0.1%100.0%

Showing all 8 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
MT District 210,301100.0%1.9%100.0%

Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).

Voters

Registered Voters
4,830
Active Voters
3,921 (81.2%)

Party Registration

This state's voter file does not record party registration.

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2023–20243,162 (65.5%)0 (0.0%)0 (0.0%)
2021–20221,982 (41.0%)0 (0.0%)0 (0.0%)
2019–20203,399 (70.4%)0 (0.0%)0 (0.0%)
2017–20182,500 (51.8%)0 (0.0%)0 (0.0%)
2015–20162,354 (48.7%)0 (0.0%)0 (0.0%)
2013–20141,775 (36.7%)0 (0.0%)0 (0.0%)
2011–20121,905 (39.4%)0 (0.0%)0 (0.0%)

Turnout counts today's registered voters with a counted ballot in the cycle's elections (the odd and even year), as a share of today's registered voters. Voters who have since left the rolls are not counted.

Browse the voter list for this district (premium access; sign-in required)

Source: Civitech voter file snapshot as of 09/10/2025. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".

Demographics

Total Population
9,892 (± 377)
Median Age
31.7
Median Household Income
$53,108 (± $4,214)
High School Graduate or Higher (age 25+)
90.4%
Bachelor's Degree or Higher (age 25+)
17.4%

Population by Age

GroupPeopleShare
Under 183,09631.3%
18 to 645,41154.7%
65 and over1,38514.0%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)3253.3%
White, not Hispanic2,34723.7%
Black, not Hispanic30.0%
Asian, not Hispanic830.8%
American Indian / Alaska Native, not Hispanic6,43765.1%
Native Hawaiian / Pacific Islander, not Hispanic10.0%
Some other race, not Hispanic230.2%
Two or more races, not Hispanic6736.8%

Source: U.S. Census Bureau, American Community Survey 2020-2024 ACS 5-year estimates (tables B01001, B01002, B01003, B03002, B15003, B19013) for this state legislative district. Estimates are survey-based; ± figures are 90% margins of error.

Citizen Voting Age Population

Total Citizen Population
9,807
Citizen Voting Age Population (CVAP)
6,709

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic9,51497.0%
Hispanic2953.0%
White2,45325.0%
Black30.0%
Asian450.5%
American Indian / Alaska Native6,43465.6%
Native Hawaiian / Pacific Islander00.0%
Two or More Races850.9%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic6,58198.1%
Hispanic1251.9%
White2,10331.3%
Black150.2%
Asian220.3%
American Indian / Alaska Native4,40965.7%
Native Hawaiian / Pacific Islander10.0%
Two or More Races300.4%

Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).