About this map
This map renders Marion County's exact administrative boundary as defined by the U.S. Census Bureau's TIGER/Line cartographic files — the same source used by federal agencies, state GIS portals, and academic researchers. The county occupies 381 square miles and shares borders with 4 neighboring counties.
The map is fully responsive — it scales cleanly from a phone screen to a 4K monitor without distortion, and prints cleanly on letter-size paper. Vector geometry means borders stay sharp at any zoom level.