Spearfish leans heavily Republican by roughly 32 points: about 34% of voters vote Democratic and 66% Republican.
About 68% of adults in Spearfish typically vote, above the U.S. average of about 62%. Among adults in Spearfish, ~23% vote Democratic, ~45% Republican, and ~32% don't vote. The map below shows estimated turnout by block group.
How Spearfish compares
Among cities within 25 miles, Spearfish is the least Republican-leaning.
Politically, Spearfish sits close to the rest of South Dakota.
Politics vary noticeably by neighborhood within Spearfish. The northeast side is the most Republican-leaning (R+53) and the south side is the least Republican-leaning (R+11), a spread of about 42 points.
Why Spearfish leans the way it does
This analysis examined 14,881 data points per city to find what predicts political lean and turnout. The items below are a few correlations that stood out for Spearfish, not a ranked or complete list of what matters most.
Spearfish votes Republican even though it is densely developed (about 44%, far above the South Dakota average of 9%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
Walkability and Democratic lean
Places with a highly walkable street grid tend to lean Democratic; Spearfish, SD sits in the top quarter nationally on this measure. A walkable street grid does not change how people vote; it mostly reflects how urban a place is.
Why turnout in Spearfish looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Spearfish 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 72%, about 12 points above the U.S. average of 60%. High high-school completion lines up with higher turnout, and about 96% of adults in Spearfish have completed high school, above 86% of cities. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- St. Onge, SD R+57
- Central City, SD R+51
- Trojan, SD R+51
- Lead, SD R+33
- Deadwood, SD R+49
- Belle Fourche, SD R+56
- Whitewood, SD R+53
- Fruitdale, SD R+72
- Beulah, WY R+74
Cities with Similar Populations
- Commerce, GA R+57
- Murraysville, NC Even
- Green Cove Springs, FL R+38
- Sayville, NY R+18
- Gilbertsville, PA R+14
- Fairview Heights, IL D+18
- Las Vegas, NM D+29
- Chesnee, SC R+60
- Glenmont, MD D+51
- Franklin Farm, VA D+36
All Local Stats
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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.