The map below shows rural, urban and exurban counties across the United States. Rural counties are "non metropolitan," according to the U.S. Census Bureau. Urban counties are metropolitan. Exurban counties are metropolitan, according to the Census Bureau, but they have a large percentage of rural residents.
When we write about rural, urban and exurban counties in Yonder stories, this is the map we go by. If you want a high-resolution version of this map, go here.
Tim Murphy