South Dakota State Senate District 21

State Legislative District Profile (Upper Chamber)

Overview

District ID
sd-sd-021
State
South Dakota
Chamber
Upper chamber (state senate)
District Code
021
Land Area
4,864.6 sq mi
Water Area
103 sq mi

Boundary

Boundary of South Dakota State Senate District 21

Boundary as GeoJSON

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

Counties

CountyOverlapShare of district landShare of county land
Tripp County1612.46 sq mi33.1%100.0%
Charles Mix County1097.49 sq mi22.6%100.0%
Gregory County1014.95 sq mi20.9%100.0%
Aurora County708.46 sq mi14.6%100.0%
Douglas County431.80 sq mi8.9%100.0%

Showing all 5 counties

Places

PlaceOverlapShare of district landShare of place land
Marty CDP3.22 sq mi0.1%100.0%
Winner city2.30 sq mi<0.1%100.0%
Wagner city1.89 sq mi<0.1%100.0%
Gregory city1.72 sq mi<0.1%100.0%
Hamill CDP1.22 sq mi<0.1%100.0%
Platte city1.05 sq mi<0.1%100.0%
Lakeview Colony CDP0.99 sq mi<0.1%100.0%
Armour city0.94 sq mi<0.1%100.0%
Corsica city0.84 sq mi<0.1%100.0%
Plankinton city0.76 sq mi<0.1%100.0%
Delmont city0.76 sq mi<0.1%100.0%
Lake Andes city0.75 sq mi<0.1%100.0%
Geddes city0.73 sq mi<0.1%100.0%
Pickstown town0.61 sq mi<0.1%99.7%
Burke city0.56 sq mi<0.1%100.0%
Herrick town0.52 sq mi<0.1%100.0%
Ideal CDP0.51 sq mi<0.1%98.7%
Dallas town0.51 sq mi<0.1%99.9%
Dante town0.50 sq mi<0.1%99.9%
White Lake city0.41 sq mi<0.1%100.0%
Bonesteel city0.35 sq mi<0.1%99.9%
Platte Colony CDP0.31 sq mi<0.1%100.0%
Clearfield Colony CDP0.30 sq mi<0.1%99.9%
Fairfax town0.30 sq mi<0.1%99.9%
Colome city0.29 sq mi<0.1%100.0%

Showing top 25 of 34 places

Overlapping Congressional Districts

Congressional districtPopulation in bothShare of this district's populationShare of the congressional district's populationShare of this district's land
SD At-Large24,573100.0%2.8%100.0%

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

Voters

Registered Voters
16,659
Active Voters
15,731 (94.4%)

Party Registration

PartyVotersShare
Democratic3,79022.8%
Republican10,07360.5%
Unaffiliated9635.8%
Other parties1,83311.0%
No party recorded00.0%

Turnout by Cycle

CycleGeneralDemocratic PrimaryRepublican Primary
2023–202411,585 (69.5%)0 (0.0%)0 (0.0%)
2021–20229,813 (58.9%)0 (0.0%)0 (0.0%)
2019–202011,015 (66.1%)0 (0.0%)0 (0.0%)
2017–20189,659 (58.0%)0 (0.0%)0 (0.0%)
2015–20169,313 (55.9%)0 (0.0%)0 (0.0%)
2013–20147,461 (44.8%)0 (0.0%)0 (0.0%)
2011–20128,623 (51.8%)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 01/20/2026. These are registered voters, separate from the Census population figures. Counts under 10 are suppressed and shown as "<10".

Demographics

Total Population
24,378 (± 180)
Median Age
40.7
Median Household Income
$65,719 (± $3,468)
High School Graduate or Higher (age 25+)
90.6%
Bachelor's Degree or Higher (age 25+)
22.6%

Population by Age

GroupPeopleShare
Under 186,52526.8%
18 to 6412,43351.0%
65 and over5,42022.2%

Population by Race and Hispanic Origin

GroupPeopleShare
Hispanic or Latino (any race)6732.8%
White, not Hispanic18,73976.9%
Black, not Hispanic1260.5%
Asian, not Hispanic1280.5%
American Indian / Alaska Native, not Hispanic3,50814.4%
Native Hawaiian / Pacific Islander, not Hispanic100.0%
Some other race, not Hispanic170.1%
Two or more races, not Hispanic1,1774.8%

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
24,112
Citizen Voting Age Population (CVAP)
17,630

Citizen Population by Race/Ethnicity

GroupCitizensShare
Non-Hispanic23,60897.9%
Hispanic5012.1%
White18,79477.9%
Black1270.5%
Asian960.4%
American Indian / Alaska Native3,51214.6%
Native Hawaiian / Pacific Islander140.1%
Two or More Races470.2%

Citizen Voting Age Population by Race/Ethnicity

GroupCVAPShare
Non-Hispanic17,43098.9%
Hispanic1971.1%
White14,53282.4%
Black1160.7%
Asian1170.7%
American Indian / Alaska Native2,66615.1%
Native Hawaiian / Pacific Islander00.0%
Two or More Races350.2%

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