On an individual level, death is inevitable. But on a statistical level, over time and space, deaths tell important stories.

But while researchers have suspected that geography can help predict cause of death, data of death and birth records are riddled with inaccuracies. That's why the Institute for Health Metrics and Evaluation decided to step in to fill in some of the gaps using a statistical model. The institute also tweaked the model to account for age, so areas with larger populations of older people don't skew the visualization.

A new Five Thirty Eight project visualizes 35 years of American deaths from various causes, based on that data. The patterns the interactive reveals are intriguing variations on a regional and local scale that chart health trends that have shaped the country. Reporter Ella Koeze delves into the details over at Five Thirty Eight. 

Set the interactive to display all causes of death and the counties with the highest mortality rates jump out as dark patches spotting the nation. Four of the counties in the top 10 are in the Dakotas, and Koeze writes that these areas are all either entirely or almost entirely reservation land. Though the federal government is required by law to provide medical care there, and tribal-run health care centers provide medical support, significant gaps in healthcare on reservations persist, as NPR's Misha Friedman chronicles in detail.

One trend that Koeze points out in a video overview is that mental and substance use disorders, especially in rural Appalachia and the West, are on the rise. Also visible is the rising tide of suicides affecting Western states. 

Some regional variations have roots in history. Health disparities tied to poverty, racism and poor education show patterns that bear the imprint of slavery in the south, Anna Maria Barry-Jester reports for Five Thirty Eight in a companion article where she explores some of the reasons for the patterns seen among black Americans, especially in the rural South. The article serves as the first of several the website will devote to health in the area called "The Black Belt." 

"Improving health in the Black Belt means recognizing the root causes: persistent poverty and lack of economic mobility, the challenges of living in rural America and a changing economic landscape that requires better education," she writes. "It will also mean wrestling with social demons, including some that go back centuries."

There is some good news to be found within the data: The leading cause of death, cardiovascular disease, is claiming fewer lives now than it did in the past. Overall, mortality is declining (as in, people are living longer). Set the cause of death on the interactive to HIV/AIDS and tuberculosis and watch as the mortality rates make much of the country flush deep green before fading away thanks to improved treatments and life expectancy.