Rock Valley is a Republican stronghold. About 19% of voters here vote Democratic and 81% Republican.
About 95% of adults in Rock Valley typically vote, above the U.S. average of about 62%. Among adults in Rock Valley, ~18% vote Democratic, ~77% Republican, and ~5% don't vote. The map below shows estimated turnout by block group.
How Rock Valley compares
Among cities within 25 miles, Rock Valley leans more Republican than 18 of 35 neighbors.
Rock Valley runs about 49 points more Republican than Iowa as a whole.
Politics vary noticeably by neighborhood within Rock Valley. The south side is the most Republican-leaning (R+78) and the north side is the least Republican-leaning (R+57), a spread of about 21 points.
Why Rock Valley 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 Rock Valley, not a ranked or complete list of what matters most.
Rock Valley votes Republican even though it is densely developed (about 31%, modestly above the Iowa average of 16%). State and regional patterns outweigh the Democratic lean that density usually predicts here.
Park access and Republican lean
Places with low park coverage tend to lean Republican; Rock Valley, IA 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 Rock Valley looks the way it does
Areas with strong routine healthcare access turn out at higher rates. Rock Valley 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 68%, about 8 points above the U.S. average of 60%. Learn more about the findings and methodology on the political spectrum map.
Nearby Cities
- Perkins, IA R+75
- Doon, IA R+72
- Hull, IA R+71
- Hudson, SD R+52
- Sioux Center, IA R+47
- Inwood, IA R+69
- Alvord, IA R+77
- Fairview, SD R+52
- Ireton, IA R+78
- Boyden, IA R+72
Cities with Similar Populations
- American Falls, ID R+38
- Timberville, VA R+61
- Sisseton, SD Even
- Hollywood, SC Even
- Thornwood, NY R+10
- Watseka, IL R+32
- Sansom Park, TX R+9
- Upland, IN R+34
- Delton, MI R+32
- Parma, ID R+62
Sources and methodology
Precinct-level voting records used to fit the model come from Iowa 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.