Boundary Atlas

ZIP code 51103: Sioux City, IA

ZIP code 51103 is in Sioux City, in Woodbury County, Iowa. It is in Iowa's 4th congressional district. Its state senate district is State Senate District 1; its state house districts are State House District 1 (98%) and State House District 2 (1.8%).

16,827residents (2020 Census)
12.1 sq miland area
1cities and towns
1congressional district
11voting precincts

See it on the mapAll of Iowa

City and county

City or townShare of ZIP residents
Sioux City100%

CountyShare of ZIP residents
Woodbury County100%

Town or county subdivisionShare of ZIP residents
Sioux City city100%

Congressional district

Congressional districtShare of ZIP residents
Iowa's 4th congressional district (IA-04)100%

Elected officials

OfficeMemberContactShare of residents
U.S. Representative (IA-04)Randy Feenstra (R)202-225-4426100%
U.S. SenatorChuck Grassley (R)202-224-3744 · contact formstatewide
U.S. SenatorJoni Ernst (R)202-224-3254 · contact formstatewide
State Senator (State Senate District 1)Catelin Drey (Democratic)100%
State Representative (State House District 1)J.D. Scholten (Democratic)98%
State Representative (State House District 2)Bob Henderson (R)1.8%

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 198%
State House District 21.8%

Voting precincts

11 voting precincts overlap ZIP 51103. 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:51103")

ZIP 51103 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.