Boundary Atlas

ZIP code 57331: Dimock, SD

ZIP code 57331 is in Dimock (30% of residents), in Hutchinson County (73%), Davison County (14%) and Douglas County (14%), South Dakota. 70% of its residents live outside city limits. It is in South Dakota's at-large congressional district. Its state senate districts are State Senate District 19 (73%), State Senate District 20 (14%) and State Senate District 21 (14%); its state house districts are State House District 19 (73%), State House District 20 (14%) and State House District 21 (14%).

452residents (2020 Census)
68.3 sq miland area
1cities and towns
1congressional district
3voting precincts

See it on the mapAll of South Dakota

City and county

City or townShare of ZIP residents
Dimock30%

CountyShare of ZIP residents
Hutchinson County73%
Davison County14%
Douglas County14%

Town or county subdivisionShare of ZIP residents
Dimock town30%
Starr township25%
Cross Plains township18%
Rome township14%
Washington township14%

Congressional district

Congressional districtShare of ZIP residents
South Dakota's at-large congressional district (SD-AL)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 1973%
State Senate District 2014%
State Senate District 2114%

State house districtShare of ZIP residents
State House District 1973%
State House District 2014%
State House District 2114%

Voting precincts

3 voting precincts overlap ZIP 57331. Map them, with each precinct's share of the ZIP's residents.

Get this in your AI agent

Your agent can get these cities, counties, districts and precincts with their shares, and their GeoJSON boundaries, from Boundary Atlas. Add https://atlas-production-d344.up.railway.app/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:57331")

ZIP 57331 here is the Census Bureau's ZIP Code Tabulation Area, which approximates the USPS ZIP Code; PO-box-only ZIPs have none. Districts are the maps in force for the November 3, 2026 election.