Who is my county supervisor?

Iowa county supervisor district lookup — free, by address, ZIP, or a tap on the map.

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Each of Iowa's 99 counties is governed by a three- or five-member board of supervisors — but they do not all elect it the same way. Iowa law gives every county a choice of three plans: elect every supervisor at large; draw residence districts but still elect everyone countywide; or draw single-member districts that each elect one supervisor. The tool finds your county's plan, your district where one is drawn, and — where the county publishes the pairing — the supervisor elected from it.

Find your county supervisor district →

Opens the map with the county and supervisor district layers on. Search your address or ZIP, or tap your location.

The three plans, and what each means for the answer

Which plan your county uses decides what "my supervisor" can even mean, so the card says which one applies before it says anything else. In the plan data the map ships today, 41 counties elect at large, 15 by residence district and 40 by single-member district; two are between plans.

A county between plans — one that has voted to change how it elects its board but whose new districts are not yet in the data — shows a status line saying so rather than a district it cannot identify.

What the lookup shows

Select any point in Iowa and the supervisor district card shows the county, the district number (or "At-large", or "Districts pending"), which plan the county uses and what that means for the election, the board's size, the district's 2020 population, and a link to the county's own board.

In single-member-district counties that publish which supervisor sits for which district, the card also names the supervisor and their party, and marks the board's chair where the county says who holds it. The board office's phone number rides its own labelled row, because every one of those counties publishes one number for the whole board and it is not any one supervisor's line. A name never appears against a district in an at-large or residence-district county, because that would claim an election that did not happen.

Where the data comes from

District boundaries come from the Iowa Legislature's statewide County Supervisor Districts layer, pre-built and shipped with the app so the lookup works offline and never waits on a server. Five counties are carried from their own publications instead, because the state's layer is behind them: Black Hawk's adopted five-district plan from the county's own GIS; Story's three districts from the County Auditor's own district map, resolved to whole census blocks and matching the Legislative Services Agency's published populations district by district; Jones's and Tama's five districts each from files the county's own office sent, checked the same way against populations published outside the drawing; and Johnson's plan facts from the county's own site, pending real district geometry. Jones is absent from the state's own layer altogether, so its own file is the only map of its districts.

Iowa publishes no statewide roster of county supervisors. Board sizes and each county's official site come from the Iowa State Association of Counties' member directory; the district-to-supervisor pairing comes from each county's own board page, in the single-member counties that publish it; and the chair comes from each county's own board page or, for a few of the largest, its board minutes, re-read weekly because the chair is chosen by the board's own January vote. Every source is on the sources & data layers page. The map is free, requires no login, and sets no tracking cookies.

Not for legal or official use. Boundary and roster data come from public sources that explicitly disclaim legal precision. Confirm district assignments and officeholders with the relevant government office before relying on them for anything official.

Every board of supervisors, county by county

Every Iowa county whose roster this project has: 97 counties, 371 people, each name published by the county itself. 40 elect at large, with no districts.

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