Boundary Atlas

ZIP code 91978: Spring Valley, CA

ZIP code 91978 is in Spring Valley (95% of residents) and Jamul (4.5%), in San Diego County, California. It is in California's 51st congressional district (95%) and California's 52nd congressional district (4.7%). Its state senate districts are State Senate District 39 (95%) and State Senate District 18 (4.7%); its state house districts are Assembly District 79 (95%) and Assembly District 75 (4.7%).

9,949residents (2020 Census)
11.9 sq miland area
2cities and towns
2congressional districts
8voting precincts

See it on the mapAll of California

City and county

City or townShare of ZIP residents
Spring Valley95%
Jamul4.5%

CountyShare of ZIP residents
San Diego County100%

Town or county subdivisionShare of ZIP residents
San Diego CCD95%
Jamul CCD4.7%

Congressional districts

Congressional districtShare of ZIP residents
California's 51st congressional district (CA-51)95%
California's 52nd congressional district (CA-52)4.7%

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 (CA-51)Sara Jacobs (D)202-225-204095%
U.S. Representative (CA-52)Juan Vargas (D)202-225-80454.7%
U.S. SenatorAdam B. Schiff (D)202-224-3841statewide
U.S. SenatorAlex Padilla (D)202-224-3553 · contact formstatewide
State Senator (State Senate District 39)Akilah Weber Pierson (Democratic)619-688-670095%
State Senator (State Senate District 18)Steve Padilla (Democratic)760-398-64424.7%
Assembly Member (Assembly District 79)LaShae Sharp-Collins (Democratic)619-465-790395%
Assembly Member (Assembly District 75)Carl DeMaio (R)858-566-75384.7%

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: 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 3995%
State Senate District 184.7%

State house districtShare of ZIP residents
Assembly District 7995%
Assembly District 754.7%

Voting precincts

8 voting precincts overlap ZIP 91978. 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://boundarymcp.com/mcp to Claude, ChatGPT, Cursor or Codex (free, no key; how), then:

related_geographies(id="us:zcta:91978")

ZIP 91978 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.