How small a town can support a Unitarian Universalist congregation? In time, I hope to answer this, but for the moment want to consider the middle scale of United States habitations: the micropolis.
As I've mentioned before, a micropolitan area "consists of one or more counties and includes the counties containing the core urban area, as well as any adjacent counties that have a high degree of social and economic integration (as measured by commuting to work) with the urban core." (Cite, with data products) The urban core area of a micropolitan area, as opposed to a metropolitan area, has at least 10,000 but fewer than 50,000 persons. In a less statistical frame, we might call them small cities or market towns, with the understanding that they include outlying areas. Mount Pilot, and by extension Mayberry, say. There are 581 micropolitan areas in the United States.
I spent much of the New Year's Day weekend grapling with UUA membership list and OMB and Census data to connect main congregational address zip codes with Census Bureau Statistical Area code, and thence to those identifying micropolitan area. (Some other time I'll filter out which congregations are in metropolitan area, and which area in rural areas.) Yes, there may be some errors, and when I publish my data files, I would appreciate your review and comment.
Remarkably, there are 186 Unitarian Universalist Association member congregations in 157 micropolitan areas. Yes, some areas have more than one congregation and in one case there's a cluster of congregations. Most of these congregations are among the smallest in the UUA, but it should make us a bit more grateful and graceful towards those who can continue a ministry in less-populated areas and often at quite a distance from other congregations.
There are plenty of interesting statistics, but after all that work, I don't want to give them up all at once.
So what's the smallest micropolitan area with a UUA-member congregation?
Kodiak, Alaska. Home of the Kodiak Unitarian Universalist Fellowship. Membership, 16; area population (2009 estimate), 13,346. Its nearest congregational neighbor by boat or air -- Kodiak is on an island -- is in Seward, 232 miles away (and 10 hours by ferry).
The CONUS runner-up is Vermillion, South Dakota. Home of the ambiguously named Unitarian (Universalist Fellowship of Vermillion. Membership, 7; area population (2009 estimate), 13,490. Its nearest congregational neighbor is 58 miles away in Sioux City, Iowa.
Next: the biggest areas without a Unitarian Universalist congregation.