According to a recent study, Johnson County has been named one of the healthiest counties in the country for children.

U.S. News & World Report and the University of Wisconsin’s Population Health Institute have named America’s 50 Healthiest Counties for Kids, and Johnson County has made the cut.

The first-ever national study measures both the health and environmental factors affecting children under the age of 18, including rates of low birth weight, infant deaths, injury deaths, and teen births, the release said. Environmental factors included rates of childhood poverty and insurance coverage, local air quality, access to parks, and rates of adult smoking and obesity.

Among the rankings, Johnson County scored an 88.5 out of a possible 100, placing 12th in the nation. It was the only Iowa county to make the top-50 list.

Johnson County Supervisor Terrence Neuzil attributed the high ranking to the local culture promoting healthy, active lifestyles, local investment in preventive health measures, and the quality of area health-care facilities.

“Johnson County is incredibly active in its investment in prevention programming,” he said. “Without any question, we prioritize that higher than most communities, certainly in the state of Iowa. It’s that old saying of an ounce of prevention and a pound of cure — we take that to heart in Johnson County, and obviously, that’s being recognized.”

Marin County, Calif., earned the top ranking — and a perfect score — among the roughly 1,200 counties surveyed. In all, the United States has 3,143 counties.

States in which county-level information on resident’s health are not recorded were excluded from the rankings, the release said.