An anonymous reader writes "I'm not a big fan of heat maps, but the US Census Bureau has just released a set of maps that succinctly capture average income distribution across the US. BusinessInsider points out that well over half of the most affluent counties in the US are concentrated in the Northeast (counting Virginia, presumably for the suburbs of Washington, D.C. located in that southern state). Of course, the cost of living is higher in those counties as well. Meanwhile, poor counties tend to be clustered in the southeast and in southwestern states on the Mexican border. There is good news for the northern prarie states, though, particularly North and South Dakota, as they lead in the number of counties with gains in household income over the past five years."