Tag Archives: county

County Size, Part 2

In a previous post, we looked at county sizes across the US based on their land area. Let’s do a quick follow up and look at county size based on population.

There are 3,142 counties (and county-equivalents) in the US. Because there are many counties with small populations and relatively few counties with very large populations, it makes sense to group them on a logarithmic scale. We’ll look at the number of counties in each of the following population ranges:

  • Below 1,000 (<1k)
  • 1,000-10,000 (1k-10k)
  • 10,000-100,000 (10k-100k)
  • 50,000-100,000 (50k-100k)
  • 100,000-500,000 (100k-500k)
  • 500,000-1,000,000 (500k-1m)
  • 1,000,000-10,000,000 (1m-10m)
  • 10,000,000 and up (>10m)

The number of counties in each range is shown below.


Over two-thirds of counties have population less than 50k, with almost half of all counties in the US falling into the 10k-50k range. There are 42 counties with 1m-10m people, and of course, one unique county with over 10m 😉

Some other interesting data points on county sizes:

  • The average county size is just over 100k (101,482 to be exact).
  • The median county size is 25,715 (half of all counties have a smaller population).
  • The population weighted average county size is about 1,150,000.
  • The median American lives in a county with population 473,279 (Staten Island). Half of all Americans live in larger counties and half live in smaller counties.

Here’s the breakdown by how many people live in each range, along with the population change for each range from 2010 to 2014:


The striking thing here is the difference in population growth. Counties under 50k people shrank, and counties in the 50k-100k grew slowly, at 1.29%. Population growth was much stronger in counties above 100k people. Even LA County, with its high housing costs and large population base, grew at almost 3%, just below the national growth rate of 3.07%. The fastest growth was in the 1m-10m range, followed by the 500k-1m range.

I wanted to investigate in a little more detail, so for each population range, I sorted counties by growth rates. The table below shows the results


For the three groups below 50k (under 1k, 1k-10k, and 10k-50k), about two thirds of counties lost population between 2010 and 2014. For the 50k-100k range, just over one third of counties lost population. For the 100k-500k range, just under 20% of counties lost population. Of the 136 counties with population above 500k, only 6 lost population. These were Wayne MI (Detroit), Cuyahoga OH (Cleveland), New Haven CT, Monmouth NJ (NYC burbs), Montgomery OH (Dayton), and Camden NJ.

This stark difference between small counties and large counties reflects recent trends in the US of large metropolitan areas gaining population while rural areas and small cities struggle or decline.

The US is a big place, and it would foolhardy to try to come up with overarching reasons. Different regions struggle for different reasons: rural counties in the High Plains have been shrinking for decades due to the inherent difficulty of dryland farming, small industrial cities have not been able to renew themselves the same way larger cities did, and coal mining counties in places like West Virginia have been hammered by low coal prices.

At a macro level, no one really knows how to create local economic prosperity in these places. Many people expected better communications technology (the internet) to make small cities and rural areas more connected, making it easier for people to work remotely and spread prosperity. That hasn’t happened. Why is anyone’s guess. For now, the important thing for those of us in large counties is to support policies that allow the creation of more housing, to allow people from small cities and rural areas to be able to move to places where they have more opportunities.

County Size

A short follow up to the post about land surveying and subdivision systems: Daniel Kay Hertz mentions that county sizes are similarly affected, and are discusses in William Fischel’s new book.

I haven’t read the Fischel book (and taking the deplorable lack of posting here as indicative of limited time for extracurriculars, I won’t be any time soon) but I did manage to put together a quick look at county sizes in the US. Here’s a table of average and median county sizes for the US excluding Alaska, which has such low population density that much of its territory is not divided into jurisdictions below the state level.


The table is color-coded: red = South (get it?), blue = North (obviously), green = Midwest (because farms), orange = West (sunsets), white = Hawaii and Texas (because they’re special). Let’s sort things out by region and see if any patterns show up.


The South seems to generally have the smallest counties. In the rest of the country, there are only 3 states with average county size under 500 square miles (NJ, RI, and IN, the most southern of northern states), while in the South there are 5. States that are further west within the south seem to have larger counties. Georgia is famous for its small, numerous counties, which help frustrate regional planning efforts. Virginia has the smallest average save tiny Rhode Island because many cities in Virginia exist as their own entity outside of any county.

The North and Midwest have similar county sizes, with an average of around 800 square miles in both. It should be noted that in legal terms, counties don’t exist in Connecticut or Rhode Island at all. County government has been completely abolished and the counties serve only as districts of services administered by the state. Massachusetts has a strange situation, having formally abolished 8 of its 14 counties.

The West is typified by much larger counties, with an average of almost 2,900 square miles. Arizona’s and Nevada’s average counties are larger than the 3 smallest states, and the largest county, San Bernardino, is larger than the 9 smallest states.

The West could be further subdivided into the Mountain West/Pacific Northwest and the Southwest. This division splits California in half, assigning 12 counties to SoCal (San Luis Obispo, Kern, Mono, Inyo, San Bernardino, Santa Barbara, Ventura, Los Angeles, Orange, Riverside, San Diego, Imperial) and the rest to NorCal. The Mountain West/Pacific Northwest has an average county size of about 2,250 square miles while the Southwest has the true giants, averaging over 4,700 square miles.


Based on the county sizes of the South, North, and Midwest, it seems that the governing land survey system had relatively little impact on county sizes. The North and Midwest in particular ended up with almost the same average size, despite the former being almost entirely metes and bounds and the latter being almost entirely US Public Land Survey System (USPLSS).

My guess is that there were two factors that influenced county size: suitability of land for frontier industry like farms and mining, and the types of transportation available at the time the county was established.

The first factor was also proposed to impact suburbanization patterns, and it is probably the easiest to see. If the land was not suitable for agriculture or mining, it would not be densely settled, and there would be no need to create new counties. This is why Maine has by far the largest county size in the North: its vast northern woods were never converted into small farms because of unfavorable climate. This also explains why Michigan, Minnesota, North Dakota, and South Dakota have the largest county sizes in the Midwest; they also contain large areas that were unsuitable for agriculture.

As has been widely discussed elsewhere, the suitability of the US for agriculture decreases as you move west towards the Great Plains and Mountain West. Looking at a map of counties in Nebraska or Colorado, one can almost visualize the wave of regular square USPLSS-centric counties marching westward, breaking up on the Sand Hills, and finally dying at in the dry steppes at the foot of the Rockies.

Texas is special because it straddles several regions. Its eastern counties, while not small, follow irregular borders. Further west, there are many almost regular square counties of about 900 square miles. West of the Pecos, Texas counties are larger and more like the Southwest.

The second factor, the time the county was created, can be seen in places like California. Many of Northern California’s small counties date to the Gold Rush, before there were even any railroads to speak of in the state. This is likely due to the need to have law enforcement and administrative services within a reasonable amount of traveling time. For example, Alpine County, on the east side of the Sierra Crest, was created in 1864 during a silver boom. Even today, there are only 5 roads into Alpine County, and 2 are closed during the winter with another 2 frequently affected by snow, and the last leading into Nevada. The relative isolation caused by very poor transportation infrastructure necessitated small counties, in order to have functional government.

In contrast, Southern California remained relatively unpopulated until the 20th century. At the time of its creation, Alpine County had a larger population than LA County or SB County. By the time LA started to boom, though, railroads were well established, autos were in development, and long distance communication by telegraph was much easier.

Simply put, there’s no longer any compelling need to create new counties. The Southwest’s large counties, established to govern vast empty areas, remain as such as they grow into some of America’s largest urbanized areas. This accident of history results in some fortuitous circumstances, because it makes it possible to have significant regional impacts by acting at the county level. A worthwhile infrastructure project on the east coast might involve multiple counties if not multiple states; in San Francisco it will almost certainly involve multiple counties; in SoCal, Las Vegas, or Phoenix, the county is usually enough.