Boundary Atlas

ZIP code 90604: South Whittier, CA

ZIP code 90604 is in South Whittier (70% of residents), East Whittier (26%) and Whittier (3.5%), in Los Angeles County, California. It is in California's 41st congressional district. Its state senate districts are State Senate District 34 (96%) and State Senate District 30 (3.6%); its state house districts are Assembly District 64 (96%) and Assembly District 56 (3.5%).

40,110residents (2020 Census)
4.2 sq miland area
3cities and towns
1congressional district
16voting precincts

See it on the mapAll of California

City and county

City or townShare of ZIP residents
South Whittier70%
East Whittier26%
Whittier3.5%

CountyShare of ZIP residents
Los Angeles County100%

Town or county subdivisionShare of ZIP residents
Whittier CCD100%

Congressional district

Congressional districtShare of ZIP residents
California's 41st congressional district (CA-41)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 3496%
State Senate District 303.6%

State house districtShare of ZIP residents
Assembly District 6496%
Assembly District 563.5%

Voting precincts

16 voting precincts overlap ZIP 90604. 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:90604")

ZIP 90604 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.