Boundary Atlas

ZIP code 57426: Oneota, SD

ZIP code 57426 is in Brown County, South Dakota, outside any city or Census-designated place. It is in South Dakota's at-large congressional district. Its state senate district is State Senate District 1; its state house district is State House District 1.

37residents (2020 Census)
6.0 sq miland area
0cities and towns
1congressional district
1voting precincts

See it on the mapAll of South Dakota

City and county

Outside any city or Census-designated place.


CountyShare of ZIP residents
Brown County100%

Town or county subdivisionShare of ZIP residents
Oneota township100%

Congressional district

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

Elected officials

OfficeMemberContactShare of residents
U.S. Representative (SD-AL)Dusty Johnson (R)202-225-2801100%
U.S. SenatorJohn Thune (R)202-224-2321 · contact formstatewide
U.S. SenatorMike Rounds (R)202-224-5842 · contact formstatewide
State Senator (State Senate District 1)Michael Rohl (R)100%
State Representative (State House District 1)Logan Manhart (R)100%
State Representative (State House District 1)Nick Fosness (R)100%

Officials serving now (members of Congress until January 3, 2027). Sources: State legislators: Open States (public domain); Members of Congress: the @unitedstates project, congress-legislators (CC0).

Local government

State legislative districts

State senate districtShare of ZIP residents
State Senate District 1100%

State house districtShare of ZIP residents
State House District 1100%

Voting precincts

1 voting precinct overlap ZIP 57426. Map them, with each precinct's share of the ZIP's residents.

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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:57426")

ZIP 57426 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.