Census Bureau: 94.6 Percent of U.S. Is Rural Open Space

Published July 1, 2003

Data newly available from the 2000 Census show that at least 94.6 percent of the United States is rural open space, calling into question one of the most common arguments made in defense of smart growth and compact urban development: that we are “running out” of open space.

The Census Bureau counts population and land area in a variety of categories:

  • Urbanized areas include contiguous areas of 50,000 people or more at densities of 1,000 people per square mile or more;
  • Urban clusters include contiguous areas of 2,500 to 50,000 people at densities of 1,000 people per square mile or more;
  • Places include, in addition to the above, any incorporated area or other concentrations of people identified by the Census Bureau.

Specific definitions of these and other Census terms can be found on the Internet at http://www.census.gov/geo/www/tiger/glossary.html.

Urbanization on the Rise

More than two out of three Americans live in urbanized areas. These areas collectively cover 2 percent of the nation’s land area. Counting urbanized areas and urban clusters together, nearly four out of five Americans live in an urban setting. Urbanized areas and urban clusters cover 2.6 percent of the nation’s land.

Remaining “places” account for just 4.4 percent of the U.S. population, but they cover 2.8 percent of the land. Their density is far lower than the density of urbanized areas and urban clusters. The average urbanized area has nearly 2,700 people per square mile, and the average urban cluster has close to 1,500 people per square mile. But the average place (outside of urban areas) has just 133 people per square mile.

In many cases, this is because small towns have large corporate boundaries, only portions of which are occupied. This is most noticeable in Alaska, where many cities have legal boundaries that include thousands of square miles of unoccupied land. As a result, the density of Alaska’s non-urban places averages just 7 people per square mile.

Non-urban place densities in Arizona, California, Hawaii, Montana, Nevada, and Wyoming average between 30 and 100 people per square mile. In all other states except Nebraska, non-urban place densities range from 100 to 500 people per square mile. Nebraska is the only state whose non-urban places approach urban densities: 805 people per square mile.

So are places “developed”? The Census Bureau counts them as “rural.” Only people living in urbanized areas or urban clusters are counted as “urban.” At the same time, a town of 1,000 people is obviously not “rural open space.” Conservatively, only those areas outside of any “place” can be considered rural open space. But it is clear that large portions of the rural places are also rural open space.

Together, urbanized areas, urban clusters, and rural places occupy 5.4 percent of the nation’s land, while urban areas alone cover just 2.6 percent. Rural open space thus covers between 94.6 and 97.4 percent of the land in the United States.

State-specific Analysis

On a state-by-state basis:

  • Four states–Connecticut, Massachusetts, New Jersey, and Rhode Island–are 30 to 40 percent urbanized and, counting rural places, 40 to 44 percent developed.
  • Delaware and Maryland are 15 to 20 percent urbanized and 18 to 23 percent developed.
  • Florida is 11 percent urbanized and 16 percent developed.
  • Six states–New Hampshire, New York, North Carolina, Ohio, Pennsylvania, and Tennessee–are 6 to 10 percent urbanized and 10 to 13 percent developed.
  • All other states are less than 7 percent urbanized and 10 percent developed.

Although California is the nation’s most populated state, it is hardly running out of land. More than 94 percent of Californians live in urban areas that cover just 5.1 percent of the state. When rural places are added, no more than 8.6 percent of the state is developed. Since California’s rural places have an average density of just 93 people per square mile, most of their land area probably qualifies as rural open space. The nation’s second-most populated state, Texas, is even less heavily developed: 2.7 percent urbanized and 5.0 percent developed.

Unfortunately, data from the 2000 Census are not comparable with numbers from the 1990 Census because the Census Bureau changed many of its definitions. Among other things, urbanized areas were redefined to exclude many undeveloped areas. This led, on average, to a 10 percent increase in population density of urbanized areas.

Despite growing populations, the 2000 Census reported many areas were smaller than measured by the 1990 Census. The new data are probably more accurate, but it is difficult to tell from them how fast land is being urbanized.

Randal O’Toole is senior economist with the Thoreau Institute and author of the recent book, The Vanishing Automobile and Other Urban Myths. His email address is [email protected]; the Thoreau Institute’s Web site is at http://www.ti.org.

For more information …

An Excel spreadsheet with complete data on land areas and populations of urbanized areas, clusters, rural places, and other rural land by state can be downloaded from http://americandreamcoalition.org/censusurbanareas.xls. A comparison of the Census results with the 1997 Natural Resources Inventory can be found at http://americandreamcoalition.org/openspace.html.