Arizona's Maricopa Leads Counties in Population Growth Since 2000

Maricopa County, Ariz., gained 696,000 residents between 2000 and 2006, the largest numerical increase of the nation’s 3,141 counties, according to estimates releasedby the U.S. Census Bureau.

This increase surpasses the total population of all but 15 U.S. cities. Maricopa County, which includes Phoenix, has 3.8 million residents, making it the nation’s fourth largest county.

“The dramatic increase in Maricopa County’s population is the main reason Arizona became the nation’s fastest-growing state between 2005 and 2006,” said Census Bureau Director Louis Kincannon, referring to the state population estimates released last December. “Maricopa’s growth has been remarkable, adding nearly 3 million residents since the 1970 census.”

Harris County, Texas, had the second largest numeric increase between 2000 and 2006, at 486,000, and totaled 3.9 million. Riverside, Calif. (481,000); Los Angeles (429,000); and Clark, Nev. (402,000) rounded out the top five county gainers. (See Table 1.)

Among the 20 fastest-growing counties from 2000 to 2006, 13 were in the South, four in the West and three in the Midwest.

Among the 10 counties that added the largest number of residents between 2000 and 2006, three were in Texas (Harris, Tarrant and Collin), three in California (Riverside, Los Angeles and San Bernardino), one in Georgia (Gwinnett) and one in Illinois (Will). Among the 20 counties with the largest numeric gains, 19 were in the South or West.