Looks like that is just an area that straddles the border between Tennessee and Kenucky. Though it maps to more than one state, it is a single, connected region

Looks like that is just an area that straddles the border between Tennessee and Kenucky. Though it maps to more than one state, it is a single, connected region. Line houses are even more interesting: https://en.wikipedia.org/wiki/Line_house https://en.wikipedia.org/wiki/Line_house