Boundary Atlas

ZIP code 80304: Boulder, CO

ZIP code 80304 is in Boulder (96% of residents) and Pine Brook Hill (3.5%), in Boulder County, Colorado. It is in Colorado's 2nd congressional district. Its state senate districts are State Senate District 18 (96%) and State Senate District 15 (3.8%); its state house districts are State House District 10 (69%) and State House District 49 (31%).

27,532residents (2020 Census)
9.0 sq miland area
2cities and towns
1congressional district
19voting precincts

See it on the mapAll of Colorado

City and county

City or townShare of ZIP residents
Boulder96%
Pine Brook Hill3.5%

CountyShare of ZIP residents
Boulder County100%

Town or county subdivisionShare of ZIP residents
Boulder CCD91%
Bald Mountain CCD8.9%

Congressional district

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

Elected officials

OfficeMemberContactShare of residents
MayorAaron Brockett96%
U.S. Representative (CO-02)Joe Neguse (D)202-225-2161100%
U.S. SenatorJohn W. Hickenlooper (D)202-224-5941 · contact formstatewide
U.S. SenatorMichael F. Bennet (D)202-224-5852 · contact formstatewide
State Senator (State Senate District 18)Judy Amabile (Democratic)96%
State Senator (State Senate District 15)Janice Marchman (Democratic)3.8%
State Representative (State House District 10)Junie Joseph (Democratic)69%
State Representative (State House District 49)Lesley Smith (Democratic)31%

From Wikidata (community-maintained); confirm on the city's website.

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); Mayors: Wikidata (CC0).

Local government

State legislative districts

State senate districtShare of ZIP residents
State Senate District 1896%
State Senate District 153.8%

State house districtShare of ZIP residents
State House District 1069%
State House District 4931%

Voting precincts

19 voting precincts overlap ZIP 80304. 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:80304")

ZIP 80304 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.