Boundary Atlas

ZIP code 51535: Griswold, IA

ZIP code 51535 is in Griswold (56% of residents), in Cass County (84%) and Pottawattamie County (16%), Iowa. 44% of its residents live outside city limits. It is in Iowa's 3rd congressional district (84%) and Iowa's 4th congressional district (16%). Its state senate districts are State Senate District 9 (84%) and State Senate District 8 (16%); its state house districts are State House District 18 (84%) and State House District 16 (16%).

1,764residents (2020 Census)
135.3 sq miland area
1cities and towns
2congressional districts
4voting precincts

See it on the mapAll of Iowa

City and county

City or townShare of ZIP residents
Griswold56%

CountyShare of ZIP residents
Cass County84%
Pottawattamie County16%

Town or county subdivisionShare of ZIP residents
Pleasant township65%
Noble township14%
Waveland township8.1%
Wright township6.7%
Cass township3.7%
Grove township1.5%
Bear Grove township1.5%
Center townshipland only

Congressional districts

Congressional districtShare of ZIP residents
Iowa's 3rd congressional district (IA-03)84%
Iowa's 4th congressional district (IA-04)16%

This ZIP is split between districts. A mailing address in it could be in either; the map or locate_point gives the district for an exact address.

Elected officials

OfficeMemberContactShare of residents
U.S. Representative (IA-03)Zachary Nunn (R)202-225-547684%
U.S. Representative (IA-04)Randy Feenstra (R)202-225-442616%
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 9)Tom Shipley (R)84%
State Senator (State Senate District 8)Mark Costello (R)16%
State Representative (State House District 18)Tom Moore (R)84%
State Representative (State House District 16)David Sieck (R)16%

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 984%
State Senate District 816%

State house districtShare of ZIP residents
State House District 1884%
State House District 1616%

Voting precincts

4 voting precincts overlap ZIP 51535. 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:51535")

ZIP 51535 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.