Overview
- District ID
- id-sd-031
- State
- Idaho
- Chamber
- Upper chamber (state senate)
- District Code
- 031
- Land Area
- 9,284.5 sq mi
- Water Area
- 50.6 sq mi
Boundary
Boundary as GeoJSON
Source: U.S. Census Bureau TIGER/Line state legislative district boundaries.
Counties
Showing all 4 counties
Places
Showing all 19 places
Overlapping Congressional Districts
| Congressional district | Population in both | Share of this district's population | Share of the congressional district's population | Share of this district's land |
|---|
| ID District 2 | 53,043 | 100.0% | 5.8% | 100.0% |
Source: U.S. Census Bureau 2020 blocks and 2025 block equivalency files (119th Congress, 2024 state legislative plans).
Voters
- Registered Voters
- 30,886
- Active Voters
- 30,886 (100.0%)
Party Registration
| Party | Voters | Share |
|---|
| Democratic | 1,225 | 4.0% |
| Republican | 24,335 | 78.8% |
| Unaffiliated | 5,021 | 16.3% |
| Other parties | 305 | 1.0% |
| No party recorded | 0 | 0.0% |
Turnout by Cycle
| Cycle | General | Democratic Primary | Republican Primary |
|---|
| 2025–2026 | 4,889 (15.8%) | 0 (0.0%) | 0 (0.0%) |
| 2023–2024 | 27,801 (90.0%) | 0 (0.0%) | 0 (0.0%) |
| 2021–2022 | 16,862 (54.6%) | 0 (0.0%) | 0 (0.0%) |
| 2019–2020 | 22,680 (73.4%) | 994 (3.2%) | 10,964 (35.5%) |
| 2017–2018 | 14,595 (47.3%) | 257 (0.8%) | 7,774 (25.2%) |
| 2015–2016 | 16,827 (54.5%) | 166 (0.5%) | 9,894 (32.0%) |
| 2013–2014 | 10,576 (34.2%) | 137 (0.4%) | 6,493 (21.0%) |
| 2011–2012 | 13,850 (44.8%) | 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 01/12/2026. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".
Demographics
- Total Population
- 56,195 (± 148)
- Median Age
- 37.0
- Median Household Income
- $76,605 (± $3,632)
- High School Graduate or Higher (age 25+)
- 91.9%
- Bachelor's Degree or Higher (age 25+)
- 25.5%
Population by Age
| Group | People | Share |
|---|
| Under 18 | 15,705 | 27.9% |
| 18 to 64 | 31,336 | 55.8% |
| 65 and over | 9,154 | 16.3% |
Population by Race and Hispanic Origin
| Group | People | Share |
|---|
| Hispanic or Latino (any race) | 5,938 | 10.6% |
| White, not Hispanic | 48,027 | 85.5% |
| Black, not Hispanic | 69 | 0.1% |
| Asian, not Hispanic | 60 | 0.1% |
| American Indian / Alaska Native, not Hispanic | 168 | 0.3% |
| Native Hawaiian / Pacific Islander, not Hispanic | 23 | 0.0% |
| Some other race, not Hispanic | 480 | 0.9% |
| Two or more races, not Hispanic | 1,430 | 2.5% |
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
- 54,795
- Citizen Voting Age Population (CVAP)
- 39,248
Citizen Population by Race/Ethnicity
| Group | Citizens | Share |
|---|
| Non-Hispanic | 50,119 | 91.5% |
| Hispanic | 4,676 | 8.5% |
| White | 48,544 | 88.6% |
| Black | 69 | 0.1% |
| Asian | 54 | 0.1% |
| American Indian / Alaska Native | 169 | 0.3% |
| Native Hawaiian / Pacific Islander | 21 | 0.0% |
| Two or More Races | 206 | 0.4% |
Citizen Voting Age Population by Race/Ethnicity
| Group | CVAP | Share |
|---|
| Non-Hispanic | 36,449 | 92.9% |
| Hispanic | 2,802 | 7.1% |
| White | 35,359 | 90.1% |
| Black | 144 | 0.4% |
| Asian | 225 | 0.6% |
| American Indian / Alaska Native | 601 | 1.5% |
| Native Hawaiian / Pacific Islander | 14 | 0.0% |
| Two or More Races | 111 | 0.3% |
Source: Redistricting Data Hub / U.S. Census Bureau CVAP Special Tabulation (2020-2024 ACS 5-year).
