Looking at each state's best and worst further illuminates a well-known trend: The least healthy counties tend to be poor and rural, and the healthiest ones tend to be urban or suburban and upper-income.
The report isn't the first to examine county-level health. Cancer and access to health care, for example, have long been studied that way. But the new database ties standard measures - general health and the rate of premature death - with more factors that play a role in those outcomes, from smoking, obesity and binge drinking to the unemployment rate, childhood poverty, air pollution and access to grocery stores.
The report compares counties within a state, not from one state to another.
"This just paints a picture" of areas for improvement, said Dr. Patrick Remington of the University of Wisconsin, which started ranking its state's counties in 2003 and co-authored the new 50-state report with the Robert Wood Johnson Foundation.
These snapshots raise which-came-first questions. Does a poor community negatively influence its residents' health? Or does it become unhealthy because it's where high-risk populations - people who lack health care or are more likely to smoke, for example - can afford to move?
Both, says Remington. He pointed to Menominee County, ranked last in Wisconsin with 15 percent of its residents in poor or fair health and a high rate of premature death. It's an Indian reservation, and the entire county has no grocery store to counter fast-food restaurants and convenience stores, he said.
"Without a grocery store, it's hard to make a healthy choice about what you're going to eat for lunch or dinner," Remington said.
CBS News medical correspondent Dr. Jon LaPook recently spoke to Dan Buettner about a similar study. Buettner is the author of "The Blue Zones: Lessons for Living Longer from the People Who've Lived the Longest." Examples of areas he calls "blue zones" are Sardinia, Okinawa, the Nicoya Peninsula in Costa Rica, the Greek island of Ikaria, and Loma Linda, Calif.. Things residents have in common include exercising regularly, eating more vegetables and less meat, engaging in social networking, and having a sense of purpose.
Buettner teamed up with AARP the Magazine to see if he could create a healthier environment and lifestyle for the 18,000 residents of Albert Lea, Minn. It wasinvolving restaurants, schools, businesses, parents, and town leaders. They created bike and walking paths, made restaurant menus more nutritious, prohibited junk food in schools, and created projects such as a community garden and workshops that helped people become more engaged with each other.
When the five-month "Vitality Project" ended in October, 2009 a total of 3,464 residents had participated. The average projected lifespan rose by 2.9 years and residents uniformly reported feeling better physically and emotionally.
Overall, Wednesady's report found least healthy counties have childhood poverty rates more than three times higher than the healthiest counties. Residents of the least healthy counties are 60 percent more likely to be hospitalized for preventable conditions, a sign of poor primary care. A third of zip codes in the least healthy counties have at least one grocery store, compared to almost half of zip codes in the healthiest counties.
The report pointed to disparities among neighbors. People in top-ranked Chester County, Pa., had a better shot of being healthy than residents of nearby but bottom-ranked Philadelphia.
Even high-ranked counties may find places to improve. Dane County, home to Wisconsin's capital, is on the state's top 10 list for all health factors except poor air and water quality, Remington said.
"If we step back and ask ourselves what really influences health, it's more than medical care," said Dr. Elliott Fisher of the Dartmouth Institute for Health Policy, long a proponent of county-level health research.