57039 leans heavily Republican by roughly 40 points: about 30% of voters vote Democratic and 70% Republican.
About 87% of adults in 57039 typically vote, above the U.S. average of about 62%. Among adults in 57039, ~26% vote Democratic, ~61% Republican, and ~13% don't vote. The map below shows estimated turnout by block group.
How 57039 compares
Among zip codes within 15 miles, 57039 leans more Republican than 5 of 12 neighbors.
57039 runs about 11 points more Republican than South Dakota as a whole.
Politics vary noticeably by block within 57039. The northeast side is the most Republican-leaning (R+49) and the south side is the least Republican-leaning (R+36), a spread of about 13 points.
Why 57039 leans the way it does
This analysis examined 14,881 data points per zip code to find what predicts political lean and turnout. The items below are a few correlations that stood out for 57039, not a ranked or complete list of what matters most.
Areas with many family households vote Republican. About 74% of households in 57039 are family households, about 8 points above the U.S. average of 67%.
Park access and Republican lean
Places with low park coverage tend to lean Republican; 57039, SD sits in the bottom quarter nationally on this measure. Park access does not change how people vote; it tends to track denser, higher-income areas.
Why turnout in 57039 looks the way it does
Areas with strong routine healthcare access turn out at higher rates. 57039 is in the top quarter nationally for routine-care measures such as insurance coverage, preventive screenings, and dental visits. The dental-visit rate here is about 70%, about 10 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Zip Codes
Zip Codes with Similar Populations
Sources and methodology
Precinct-level voting records used to fit the model come from South Dakota Secretary of State, Elections, distributed by the Voting and Election Science Team. Demographic inputs come from the U.S. Census Bureau (ACS 5-year estimates and the 2020 Decennial Census). Health and environmental inputs come from the CDC (PLACES and the Environmental Justice Index). Land cover comes from the USGS and EPA. Election-day and lead-up weather come from PRISM 4km daily grids and the NOAA Global Historical Climatology Network. Mail-voting and election-administration patterns come from the MIT Election Lab's Survey of the Performance of American Elections. Block-group crime detail comes from CrimeGrade. Internet data and modeling support provided by ISPreports.org.
Modeling and analysis by the BestNeighborhood data science team. Full methodology and findings: political spectrum map.
Methodology reviewed by the BestNeighborhood data team. Last updated May 2026.