Mercer County GIS Map
Mercer is one of the most repeated county names in the United States: there are 8 counties named Mercer spread across 8 states. Each one is a different local government with its own boundary, population and flood maps, so the right GIS map depends on which state you mean.
That is also why a search for Mercer GIS turns up several unrelated county systems — the name on its own does not tell you which state's mapping office you are after. Pick the state you need below.
Every county page opens an interactive GIS map of that county's official Census boundary, with FEMA flood zones, USGS elevation contours, land cover and school districts you can turn on, plus population, land area and ZIP code data.
Most people searching for Mercer County mean Mercer County, New Jersey — the largest of them, with a population of about 385,864.
All 8 Mercer Counties by state
Ordered by population, largest first.
- Mercer CountyNew Jersey (NJ) 385,864 224.5 sq mi
- Mercer CountyPennsylvania (PA) 109,257 672.5 sq mi
- Mercer CountyWest Virginia (WV) 58,563 419 sq mi
- Mercer CountyOhio (OH) 42,484 462.4 sq mi
- Mercer CountyKentucky (KY) 23,028 249.4 sq mi
- Mercer CountyIllinois (IL) 15,495 561.2 sq mi
- Mercer CountyNorth Dakota (ND) 8,337 1,042.8 sq mi
- Mercer CountyMissouri (MO) 3,482 453.8 sq mi