Boundary Atlas

ZIP code 77331: San Jacinto County, TX

ZIP code 77331 is in Coldspring (12% of residents) and Cape Royale (9.4%), in San Jacinto County, Texas. 79% of its residents live outside city limits. It is in Texas's 10th congressional district. Its state senate district is State Senate District 5; its state house district is State House District 18.

6,953residents (2020 Census)
171.1 sq miland area
2cities and towns
1congressional district
5voting precincts

See it on the mapAll of Texas

City and county

City or townShare of ZIP residents
Coldspring12%
Cape Royale9.4%

CountyShare of ZIP residents
San Jacinto County100%

Town or county subdivisionShare of ZIP residents
Coldspring CCD72%
Point Blank CCD16%
Shepherd-Evergreen CCD13%

Congressional district

Congressional districtShare of ZIP residents
Texas's 10th congressional district (TX-10)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 5100%

State house districtShare of ZIP residents
State House District 18100%

Voting precincts

5 voting precincts overlap ZIP 77331. 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:77331")

ZIP 77331 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.