[Eric in the Ozarks]

Doesn't look like much. New Madrid is right at the southern point where Illinois, Kentucky, Tennessee and Missouri run together. the Wabash fault is to the NE of St. Louis, along the border of Illinois and Indiana. I'd guess it's less than 150 miles.
My stepdad was active in the Illinois Basin with AMAX Coal and told the story of how mining companies tried to bridge this 150 differential. Most gave up trying and built a new entry from the east side of the fault because it was nearly impossible at the time to mine an underground slope through shale.

[Freedom2specul8]

That is really interesting.. I had no idea. In the part of western missouri where I was raised...we had a few tremors. As a kid, it was ‘scary’ feeling the tremors, and watching items nearby ‘shake’.