Why is Appalachian Ohio Household Income Lower Than The Rest of the State?

Limit of the Advance of Glaciers in South East Ohio

The difference in median household income between the portion of Ohio that was covered by ice during the Pleistocene era, and the portion that wasn't is stark.

The map above is pretty old and the values are in 1999 dollars, but it shows the difference well. Generally, the per capita income and household income in Appalachia is a fraction of the wealthier portion of the state. If you scan through the areas with satellite or roadside imagery, the very subtle differences in the areas tell the story.

Both regions are in the same geographic "province" of the United States--the Allegheny Plateua. The landscape of south east Ohio is what Northeast Ohio would look like if it hadn't been glaciated. In Southern Ohio, there are rolling hills where erosion has worn down the rocks and there are more or less broad valleys where streams and rivers have formed arable land, but there are also lots of little rocky hill tops with no soil, which creates a double whammy problem. In areas with severe landscapes, travel distance is longer and more energy intensive to avoid hills, so it's really like the resources of Appalachian Ohio are diluted by a factor of 1.5 or 2.

In Northeast Ohio, the little hills were worn down by glaciers and the valleys were filled in with till so there are large regions of land with deep soil. Consequently, it was possible to support cities with larger populations. (If you look at topo map of Switzerland, you see the same patterns.)

Also Appalachian Ohio became a coal mining area while the rest of the state generated wealth with diverse industrial activity and agriculture. Resource extraction businesses are often bad at creating lasting wealth for the people because there's pretty minimal value added locally, so once the coal is used up, or becomes uneconomic, the money spigot just shuts off. Also, historically, the coal mining business was pretty malignant economically and preyed on their employees, so whatever wealth was actually created by the coal trade was sucked out of those regions leaving little behind.