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%).
See it on the mapAll of California
City and county
| City or town | Share of ZIP residents |
|---|---|
| Spring Valley | 95% |
| Jamul | 4.5% |
| County | Share of ZIP residents |
|---|---|
| San Diego County | 100% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| San Diego CCD | 95% |
| Jamul CCD | 4.7% |
Congressional districts
| Congressional district | Share 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.
State legislative districts
| State senate district | Share of ZIP residents |
|---|---|
| State Senate District 39 | 95% |
| State Senate District 18 | 4.7% |
| State house district | Share of ZIP residents |
|---|---|
| Assembly District 79 | 95% |
| Assembly District 75 | 4.7% |
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://atlas-production-d344.up.railway.app/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.