From 1961 to 1999, the average life expectancy for men in the United States increased from 67 to 74 years. For women, it grew from 74 to 80 years. . . . [But] the trend to live longer stopped or reversed in many parts of the Deep South, Appalachia, Mississippi Valley, Great Plains and Texas in the 1980s and 1990s . . . To a lesser extent, the trend stalled in the Midwest and other parts of the country. During that time frame, women’s life expectancy flattened out in nearly 1,924 counties and decreased in 180 others. Men saw it stall in 427 counties and decline in 11, the researchers report in the April PLoS Medicine. . . .
[T]he United States has become a country in which life span is scarcely affected by infectious diseases, with only HIV having a significant impact. Instead, the prime factors shortening lives are high blood pressure, obesity and smoking . . . Over the long run, these lead to heart problems, stroke, diabetes, emphysema and lung cancer.
Lack of health insurance and quality health services is also identified as a key factor in the trend by the investigators.
A large share of the Colorado water systems that are contaminated are likewise in small Front Range communities.
The trend in income growth is similar as show here (via 5280.com):