Boundary Atlas

ZIP code 57551: Martin, SD

ZIP code 57551 is in Martin (42% of residents), in Bennett County, South Dakota. 58% of its residents live outside city limits. It is in South Dakota's at-large congressional district. Its state senate district is State Senate District 27; its state house district is State House District 27.

2,232residents (2020 Census)
753.1 sq miland area
1cities and towns
1congressional district
6voting precincts

See it on the mapAll of South Dakota

City and county

City or townShare of ZIP residents
Martin42%

CountyShare of ZIP residents
Bennett County100%

Town or county subdivisionShare of ZIP residents
Martin city42%
East Bennett UT41%
West Bennett UT17%

Congressional district

Congressional districtShare of ZIP residents
South Dakota's at-large congressional district (SD-AL)100%

Elected officials

OfficeMemberContactShare of residents
U.S. Representative (SD-AL)Dusty Johnson (R)202-225-2801100%
U.S. SenatorJohn Thune (R)202-224-2321 · contact formstatewide
U.S. SenatorMike Rounds (R)202-224-5842 · contact formstatewide
State Senator (State Senate District 27)Red Dawn Foster (Democratic)100%
State Representative (State House District 27)Liz May (R)100%
State Representative (State House District 27)Peri Pourier (R)100%

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 27100%

State house districtShare of ZIP residents
State House District 27100%

Voting precincts

6 voting precincts overlap ZIP 57551. 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:57551")

ZIP 57551 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.