Boundary Atlas

ZIP code 59638: Jefferson City, MT

ZIP code 59638 is in Jefferson City (78% of residents) and Clancy (17%), in Jefferson County, Montana. 5.1% of its residents live outside city limits. It is in Montana's 2nd congressional district. Its state senate district is State Senate District 38; its state house district is State House District 75.

770residents (2020 Census)
60.4 sq miland area
2cities and towns
1congressional district
1voting precincts

See it on the mapAll of Montana

City and county

City or townShare of ZIP residents
Jefferson City78%
Clancy17%

CountyShare of ZIP residents
Jefferson County100%

Town or county subdivisionShare of ZIP residents
Boulder CCD100%

Congressional district

Congressional districtShare of ZIP residents
Montana's 2nd congressional district (MT-02)100%

State legislative districts

State senate districtShare of ZIP residents
State Senate District 38100%

State house districtShare of ZIP residents
State House District 75100%

Voting precincts

1 voting precinct overlap ZIP 59638. Map them, with each precinct's share of the ZIP's residents.

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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:59638")

ZIP 59638 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.