A map by request. Here is where all those metropolitan areas without Unitarian Universalist congregations are. The usual caveats apply, but note how most are east of the population fall-off line around Interstate highway 35; these are not lost in the desert. Funny how there are two cities each named Danville (Illinois and Virginia) and Monroe (Louisiana and Michigan) on the list. Less is funny is that they're on the list at all.
And even if Unitarian Universalists did exist like a mineral (at 6.6 parts per 10,000), there's no reason why there wouldn't be a medium-sized church in metro Fort Smith, Arkansas.
Why isn't there one, or rather, why isn't there help for the people of that and other cities?