Rename East North Central, West North Central, East South Central and West South Central divisions

[King of Kensington]

Without changing the composition of these Census divisions (can't plead for shifting out of West Virginia out of South Atlantic because it's "not really coastal" etc.), are there better names?

Great Lakes works pretty well for East North Central for example.

[Del Tachi]

Great Lakes works for East North Central.

Best name for West North Central is probably (Great) Plains.

The two Southern ones are the most difficult, as the best way to divide the South has always been along a lowland/upland axis (i.e., Mississippi goes better with Virginia or Maryland than it does Arkansas or Kentucky.) 

The most prominent feature of East South Central is the Tennessee River watershed, so I'll give it the name "Tennessee Valley."  With that one renamed you could have the Texas region simply be the much cleaner sounding "South Central," although I expect you're wanting each division to have a more descriptive name.  In that case, there aren't many good choices...Arklatex has been used to refer to this four-state region for quite some time, throw in Oklahoma to make it extra cringy: OkLaTexSas?  Or use the Red River as your inspiration, since it flows through all four states? Maybe the best name would be Ozarka?