31. Los Alamos County, New Mexico
> County median household income: $106,686
> State median household income: $44,927
> Pct. households in county making $200,000 or more: 13.7%
> 2013 county unemployment rate: 4.0%

Los Alamos County had an exceptionally high median annual household income of $106,686 over the five years through 2013. Yet, income was among the most poorly distributed in New Mexico as a typical household in Los Alamos earned nearly $80,000 more than a typical household in Sierra County, the state’s poorest. Los Alamos residents also benefited from relatively low poverty and unemployment rates of 4.4% and 4.0%, respectively.

32. Nassau County, New York
> County median household income: $97,690
> State median household income: $58,003
> Pct. households in county making $200,000 or more: 15.9%
> 2013 county unemployment rate: 5.9%

As is the case with numerous other wealthy counties, high incomes in Nassau can be partly attributed to its proximity to a major metropolis. New York City, where county residents can find higher incomes and job opportunities, is within commuting distance for many in the area. A typical household earned nearly $98,000 annually in Nassau County over the five years through 2013, $63,302 more than the comparable figure in the Bronx, the state’s poorest county — this was one of the highest such income gaps nationwide.

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33. Wake County, North Carolina
> County median household income: $66,006
> State median household income: $46,334
> Pct. households in county making $200,000 or more: 6.8%
> 2013 county unemployment rate: 6.2%

During the five years through 2013, Wake County had a median annual household income of $66,006, the highest in the state although not especially high compared to the nation. The higher incomes were due in large part to the area’s well-educated workforce. Nearly half of Wake County’s adult residents had at least a bachelor’s degree between 2009 and the end of 2013, one of the highest rates nationwide.

34. Williams County, North Dakota
> County median household income: $76,210
> State median household income: $53,741
> Pct. households in county making $200,000 or more: 7.0%
> 2013 county unemployment rate: 0.9%

In recent years, residents of Williams County benefited substantially from North Dakota’s rapid economic growth. Less than 1% of the county’s workforce were unemployed in 2013, among the very lowest rates anywhere in the country. While in most affluent counties with a low unemployment rate the workforce was also well educated, this was not the case in Williams County. Less than one in five adults had at least a bachelor’s degree over the five years through 2013 — one of the lowest rates reviewed. Yet, households were still quite wealthy. Williams had a median annual household income of more than $76,000.

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35. Delaware County, Ohio
> County median household income: $89,757
> State median household income: $48,308
> Pct. households in county making $200,000 or more: 11.0%
> 2013 county unemployment rate: 5.2%

Delaware County had one of the highest median household incomes, especially when compared to the rest of Ohio. The county had a median income of nearly $90,000 over the five years through 2013, nearly $42,000 higher than the comparable state figure of just $48,308. Residents were well educated over that period, which likely helped households earn more. More than 50% of adults in the area had at least a bachelor’s degree during the five years through 2013, one of the highest proportions nationwide.