As a whole, Iowa saw its population increase 43,559 people since 2010, and it remained the 30th-most-populous state. However, only 29 of Iowa’s 99 counties gained population during the three-year span. Pottawattamie County joined Woodbury County as the only two of Iowa’s 10 largest counties to lose population since 2010. Those two counties also contain principal cities for the state’s only two metropolitan areas west of the Interstate 35 corridor.

Dallas County, which contains many of the booming suburbs just west of Des Moines, was once again Iowa’s fastest-growing county, seeing its population increase by 12.9 percent – from 66,135 to 74,641 residents – since 2010. It ranked 17th among all counties nationwide.

The entire Omaha-Council Bluffs metropolitan area gained 29,801 people (3.4 percent growth) since the 2010 Census, making it the nation’s 60th-largest with 895,151 residents. By and large, growth was associated with urban areas and neighboring counties.

On the western side of the state, only a handful of rural counties – including Ida, Crawford, Union and Sioux – saw population growth.