Related

Generated from the U.S. Census Bureau cartographic boundary release listed under Sources. All three files carry the same 88 features and the same geometry.

File	Size	Contents	Use it for
ohio-counties-census-2025.kmz	90 KB	88 named county polygons	Google My Maps, Google Earth
ohio-counties-census-2025.kml	298 KB	same, uncompressed	Google Earth, anything that wants raw KML
ohio-counties-census-2025.geojson	291 KB	same, RFC 7946	Leaflet, QGIS, Mapbox, scripts

Each county carries its name, GEOID (state+county FIPS), NAMELSAD, and the Census land and water area in square metres. Coordinates are NAD83 (EPSG:4269) longitude and latitude, as published; that is within about a metre of WGS84 and needs no reprojection for web use.

These are generalised cartographic boundaries at 1:500,000, drawn for small-scale mapping. The Census Bureau's own metadata says areas "are represented with fewer vertices than detailed TIGER/Line Shapefiles." They are not survey boundaries and should not be used as such.

Verified against Google's current My Maps help documentation (see Sources).

1. Sign in to My Maps at https://mymaps.google.com on a computer.
2. Open an existing map or create a new one.
3. In the map legend, click Add layer and give the layer a name.
4. Under the new layer, click Import.
5. Upload ohio-counties-census-2025.kmz — drag it in or pick it from your computer — then click Select.

You do not need to put the file in Google Drive first. Google's import documentation describes uploading the file directly in the Import dialog; Drive and Google Photos are named there as sources for importing photos, and the import flow may ask you to "Allow https://mymaps.google.com/ to open your Drive."

Putting the imported map on this page

Once the counties are in My Maps, the map at the top of this page can be swapped from the plain Google map to your own. Steps below are Google's own, from the help page listed under Sources.

1. Open the map in My Maps and click the Share icon in the left panel.
2. Choose Make your map public — link sharing to specific people is not enough. Google's wording is plain: "Make sure the map is public."
3. Click Done or Save changes.
4. From Share, or the menu, choose Embed on my site. Google returns an <iframe> snippet.
5. Copy just the src value out of that snippet. It looks like https://www.google.com/maps/d/embed?mid=<YOUR-MAP-ID>.
6. In this page, replace the src on the existing iframe with that URL and delete the placeholder comment above it. Leave the wrapping <div> and the other attributes alone — they carry the responsive sizing.

The embed must stay above the # heading. Every heading on this site renders as a collapsible whose body is hidden until it is hovered or focused, so an embed placed under one will not show when the page loads.

Why boundaries and not roads

Google's documented My Maps limits:

• KML and KMZ files: up to 5 MB unzipped. Other formats: up to 40 MB.
• Do not import files with more than 2,000 rows.
• A layer can hold 2,000 lines, shapes or places; a map can hold 10,000; a map can have up to 10 layers.

This boundary file is 88 features and 0.29 MB unzipped — comfortably inside every one of those.

Ohio's road network is not close. ODOT's Road Inventory — the state's official roadway centerline dataset — reports 465,332 line features statewide when queried directly. Filtered to county-jurisdiction roads alone it is 61,793. Even just the interstate, US and state routes come to 74,107. Against a 2,000-feature layer ceiling and a 10,000-feature map ceiling, there is no subset of the Ohio road network that fits, and no amount of trimming gets one there. For roads, use the sources below directly rather than trying to route them through My Maps.

• ODOT TIMS Road Inventory — the official statewide roadway centerline inventory, described by ODOT as "the State's 'official' source for certified mileage, lane miles, Federal Aid eligibility, and HPMS." Downloadable from TIMS as Excel, KMZ, SHP or GDB. Includes a JURISDICTION_CD field (C county, F federal, M municipal, P private, S state, T township) so county roads can be isolated.
• OGRIP LBRS county centerlines — Ohio's Location Based Response System publishes road centerlines county by county as zipped shapefiles, one file per county, roughly 228 MB for all 88. Currency varies a lot by county: the publisher's own index gives centerline dates from January 2019 to November 2024, so check the date for the county you care about rather than assuming.
• Census TIGER/Line roads — a per-county tl_2025_39<county FIPS>_roads.zip for each of Ohio's 88 counties, plus a single statewide primary-and-secondary roads file.

There is no ODOT county road map PDF

Searched for one across ODOT's maps publication page, its full sitemap, its public FTP tree and TIMS. ODOT does not publish a downloadable per-county road map PDF series. Its own map request form states plainly: "ODOT can only provide hard copies of State Maps. We do not stock other printed maps." County-level road detail comes from TIMS data, not from a map sheet.

U.S. Census Bureau, Geography Division — geometry for the files above. https://www2.census.gov/geo/tiger/GENZ2025/shp/cb_2025_us_county_500k.zip Nationwide county and county-equivalent boundaries; Ohio extracted by STATEFP = 39. Titled by its own metadata "2025 Cartographic Boundary File (SHP), County and Equivalent for United States, 1:500,000". Vintage 2025; the ISO metadata carries a 2026-05 date. CRS NAD83 / EPSG:4269. Verified 2026-08-09.

Google — My Maps Help, "Share, download, or print your map" https://support.google.com/mymaps/answer/3109452 Source for the share and embed steps above, including the requirement that the map be public before it can be embedded. Verified 2026-08-10.

Ohio Department of Transportation — Transportation Information Mapping System (TIMS) https://tims.dot.state.oh.us/tims/data ODOT's GIS data portal. Its own text: "Select one or multiple datasets to download datasets as EXCEL, KMZ, SHP, or GDB format." Road Inventory dataset last updated 16 June 2026; County boundaries dataset ("Boundaries of the 88 counties in Ohio") last updated 15 June 2026, owner ODOT Office of Technical Services. Verified 2026-08-09.

Ohio Department of Transportation — maps publications https://transportation.ohio.gov/business/publications/maps Carries the Official State of Ohio Map, a bicycle path map and a rail map. No county map series. Verified 2026-08-09.

OGRIP (Ohio Geographically Referenced Information Program) — data downloads https://gis1.oit.ohio.gov/geodatadownload/ Ohio's state GIS clearinghouse download tool, run by Ohio DAS. Serves OSIP imagery and elevation plus LBRS road centerlines, address points, intersections, landmarks and railroad crossings, county by county. Per-county centerline dates run 2019 to 2024; no single statewide date. Verified 2026-08-09.

U.S. Census Bureau TIGER/Line 2025 roads https://www2.census.gov/geo/tiger/TIGER2025/ROADS/ 88 per-county Ohio road files (tl_2025_39*_roads.zip). The statewide primary-and-secondary file tl_2025_39_prisecroads.zip is 10.5 MB zipped, itself over the My Maps KML ceiling. Verified 2026-08-09.

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Part of Maps. Boundary geometry is generalised and is not a legal survey.