ZIP code 78585: Starr County, TX
ZIP code 78585 is in Starr County, Texas, outside any city or Census-designated place. It is in Texas's 28th congressional district. Its state senate district is State Senate District 21; its state house district is State House District 31.
City and county
Outside any city or Census-designated place.
| County | Share of ZIP residents |
|---|---|
| Starr County | 100% |
| Town or county subdivision | Share of ZIP residents |
|---|---|
| Roma-Los Saenz CCD | 100% |
Congressional district
| Congressional district | Share of ZIP residents |
|---|---|
| Texas's 28th congressional district (TX-28) | 100% |
Elected officials
| Office | Member | Contact | Share of residents |
|---|---|---|---|
| U.S. Representative (TX-28) | Henry Cuellar (D) | 202-225-1640 | 100% |
| U.S. Senator | John Cornyn (R) | 202-224-2934 · contact form | statewide |
| U.S. Senator | Ted Cruz (R) | 202-224-5922 · contact form | statewide |
| State Senator (State Senate District 21) | Judith Zaffirini (Democratic) | 956-722-2293 | 100% |
| State Representative (State House District 31) | Ryan Guillen (R) | 100% |
Elected in 2024 under TX'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
- Starr County website: https://www.co.starr.tx.us/
- Starr County laws: search for the Starr County, Texas code of ordinances
State legislative districts
| State senate district | Share of ZIP residents |
|---|---|
| State Senate District 21 | 100% |
| State house district | Share of ZIP residents |
|---|---|
| State House District 31 | 100% |
Voting precincts
1 voting precinct overlap ZIP 78585. 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:78585")
ZIP 78585 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.