Yeah southern Indiana, Illinois, Ohio, northern Kentucky, and western Tennessee, the Ohio River Valley in essence, are culturally very similar and "appalachia-light".

But IMO that's a very far cry from eastern/south-eastern Kentucky, eastern Tennessee, western NC, WV, etc; truly core Appalachia.

Its also a far cry from mid-Indiana, which is culturally identical to northern Indiana, most of Illinois, Iowa, southern Michigan, maybe even as far as southern Wisconsin, Kansas, and Nebraska. That's Corn/Rust belt, very crop-farm oriented, dairy farms, extremely flat, but not as rural as many people think, not nearly as rural as Appalachia or the west.