Boundary Atlas

ZIP code 78644: Lockhart, TX

ZIP code 78644 is in Lockhart (69% of residents), in Caldwell County, Texas. 31% of its residents live outside city limits. It is in Texas's 27th congressional district. Its state senate district is State Senate District 21; its state house district is State House District 17.

20,813residents (2020 Census)
179.9 sq miland area
1cities and towns
1congressional district
19voting precincts

See it on the mapAll of Texas

City and county

City or townShare of ZIP residents
Lockhart69%

CountyShare of ZIP residents
Caldwell County100%

Town or county subdivisionShare of ZIP residents
Lockhart CCD96%
Martindale CCD3.8%
Luling CCD0.5%

Congressional district

Congressional districtShare of ZIP residents
Texas's 27th congressional district (TX-27)100%

Elected officials

OfficeMemberContactShare of residents
U.S. Representative (TX-27)Michael Cloud (R)202-225-7742100%
U.S. SenatorJohn Cornyn (R)202-224-2934 · contact formstatewide
U.S. SenatorTed Cruz (R)202-224-5922 · contact formstatewide
State Senator (State Senate District 21)Judith Zaffirini (Democratic)956-722-2293100%
State Representative (State House District 17)Stan Gerdes (R)512-321-3720100%

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

State legislative districts

State senate districtShare of ZIP residents
State Senate District 21100%

State house districtShare of ZIP residents
State House District 17100%

Voting precincts

19 voting precincts overlap ZIP 78644. 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:78644")

ZIP 78644 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.