The population of Texas is unevenly distributed throughout the state. In 2014, population density varied from a high of 2,891 persons per square mile in Dallas County to a low of 0.13 persons per square mile in Loving County.
One-third of Texas' 254 counties (86) had a population density of fewer than 10 persons per square mile. These counties were primarily located in the western portion of the state.
Six counties had a population in excess of 1,000 persons per square mile, including Dallas, Harris (Houston), Tarrant (Fort Worth), Bexar (San Antonio), Travis (Austin), and Collin (Plano, Carrollton, Richardson). Those 6 counties are home to nearly half (47%) of the population of the state.
Texas has been one of the fastest-growing states in the United States since the mid-1980s. See Population Characteristics in Texas.
Population growth in Texas is driven by a combination of factors—a young age structure with a large population share of childbearing age, a relatively high birth rate, a sustained pattern of high rates of both immigration from other counties, and internal migration from other states.
This growth is increasing the population density and concentration in the state's large metropolitan centers, and especially in the suburban counties around the state's largest cities.
Eleven counties added more than 50 percent to their population between 2000 and 2013. All of these counties were in the suburban ring surrounding the cities of Dallas, Houston, Austin, and San Antonio. The counties that are home to these cities—Dallas, Harris, Travis, and Bexar—increased by more than 20 percent, as did the metropolitan counties along the border.
By contrast, 85 of the 254 counties of Texas lost population between 2000 and 2012. The majority of counties losing population were concentrated in areas in West Texas and the Panhandle, counties with previously small populations.