Boundary Atlas

ZIP code 91010: Duarte, CA

ZIP code 91010 is in Duarte (81% of residents), South Monrovia Island (16%) and Irwindale (1.1%), in Los Angeles County, California. It is in California's 31st congressional district. Its state senate district is State Senate District 22; its state house districts are Assembly District 48 (100%) and Assembly District 41 (0.2%).

26,730residents (2020 Census)
6.4 sq miland area
5cities and towns
1congressional district
26voting precincts

See it on the mapAll of California

City and county

City or townShare of ZIP residents
Duarte81%
South Monrovia Island16%
Irwindale1.1%
Azusa0.3%
Bradbury0.2%

CountyShare of ZIP residents
Los Angeles County100%

Town or county subdivisionShare of ZIP residents
Upper San Gabriel Valley CCD99%
East San Gabriel Valley CCD1.4%

Congressional district

Congressional districtShare of ZIP residents
California's 31st congressional district (CA-31)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 22100%

State house districtShare of ZIP residents
Assembly District 48100%
Assembly District 410.2%

Voting precincts

26 voting precincts overlap ZIP 91010. 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:91010")

ZIP 91010 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.