Boundary Atlas

ZIP code 91730: Rancho Cucamonga, CA

ZIP code 91730 is in Rancho Cucamonga, in San Bernardino County, California. It is in California's 33rd congressional district (46%), California's 28th congressional district (42%) and California's 35th congressional district (12%). Its state senate district is State Senate District 29; its state house districts are Assembly District 50 (97%) and Assembly District 41 (3.3%).

68,883residents (2020 Census)
13.7 sq miland area
1cities and towns
3congressional districts
53voting precincts

See it on the mapAll of California

City and county

City or townShare of ZIP residents
Rancho Cucamonga100%

CountyShare of ZIP residents
San Bernardino County100%

Town or county subdivisionShare of ZIP residents
Ontario CCD100%
San Bernardino CCD<0.1%

Congressional districts

Congressional districtShare of ZIP residents
California's 33rd congressional district (CA-33)46%
California's 28th congressional district (CA-28)42%
California's 35th congressional district (CA-35)12%

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
MayorL. Dennis Michael909-477-2700100%
U.S. Representative (CA-33)Pete Aguilar (D)202-225-320146%
U.S. Representative (CA-28)Judy Chu (D)202-225-546442%
U.S. Representative (CA-35)Norma J. Torres (D)202-225-616112%
U.S. SenatorAdam B. Schiff (D)202-224-3841statewide
U.S. SenatorAlex Padilla (D)202-224-3553 · contact formstatewide
State Senator (State Senate District 29)Eloise Reyes (Democratic)909-888-5360100%
Assembly Member (Assembly District 50)Robert Garcia (Democratic)909-966-509097%
Assembly Member (Assembly District 41)John Harabedian (Democratic)626-351-19173.3%

Elected in 2024 under CA's previous congressional map; this district's lines changed for the 120th Congress (seated January 3, 2027).

Officials serving now (members of Congress until January 3, 2027). Sources: Mayors: Open States (public domain); 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 29100%

State house districtShare of ZIP residents
Assembly District 5097%
Assembly District 413.3%

Voting precincts

53 voting precincts overlap ZIP 91730. 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:

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ZIP 91730 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.