If you want to get a sense of what an economic powerhouse Washington has become in recent years, look no further than the Virginia suburb of Falls Church City.
Boasting a strong school system and positioned about six miles from the nation's capital, Falls Church has for years enticed rich families, making it the nation's richest county with median annual household income of $113,313.
"It indicates that the City of Falls Church is located in a healthy economic area in the national capital region," says Wyatt Shields, city manager for Falls Church. "We are proud of the fact that we take advantage of the city's healthy economic area to attract people to live here."
It's No. 1, but it isn't alone. In fact, four of the top ten richest counties in the nation are concentrated in the Virginia suburbs of Washington, and a fifth, Howard County, Md., is equidistant between Washington and Baltimore.
In recent decades northern Virginia has become an economic dynamo, driven by a private sector that feasts on government contracting. These counties are also home to corporate lobbyists, lawyers and consultants who work in or around the nation's capital, soaking up federal government spending. And government-related hiring manages to keep the unemployment rate in places like Falls Church City down to 5.7%.
To determine America's richest counties, we looked at median annual household income estimates from 2005 to 2009 in each county in the nation, provided by the U.S. Census' American Community Survey. The estimates are in 2009 inflation-adjusted U.S. dollars.
Nader Baroukh, the mayor of Falls Church, is not shying away from the designation of being the richest, but he does disagree with one of the U.S. Census' conclusions. "We are actually a city and not a county, but I can't comment on how the Census puts its data together," says Baroukh. "We are a small jurisdiction, about 2.2 square miles, and I think given our location it's a very attractive place to live and our top schools are one of the big attractions."
Falls Church is in fact an independent political subdivision of the state, but most Virginia counties are much larger than Falls Church, which has a population of 12,330. Whatever you want to call it, even wealthy Falls Church is not exempt from the kind of tough fiscal realities facing counties and cities across the nation. Fall Church has cut 14% of its workforce over the last three years and raised property taxes.
Nearby Loudoun County, Va., used to be a sleepy rural community just a few decades ago, but in recent years it has become a technology center and a popular Washington suburb. It is now the second-richest county in the nation with median annual household income of $112,021. Another Washington county, Fairfax County, Va., rounds out the top three with annual median household income of $104,259. Making the median high income in Fairfax County even more impressive is the fact that it has 1.1 million residents. This populous county has a massive federal government presence and is home to companies with strong connections to the government, like Freddie Mac, and intelligence agencies like the CIA and the National Counterterrorism Center.
Only counties that are part of the New Jersey suburbs of New York City can rival Northern Virginia. The richest county in the nation outside of Virginia is Hunterdon County in northwest N.J., where the median annual household income is $102,500. Rural Hunterdon County has become a magnet for rich commuters heading to New York City and even Philadelphia. Morris County, N.J., where the taxes are high but the median household income is $96,316 or Somerset County, also are among the richest counties in the nation.
Most of the richest counties in America are in the East. The richest county in the Western United States is Los Alamos, N.M., where decades of government money spent on nuclear weapons has resulted in median annual household income of $100,423. Most of the 18,000 residents of this county, which is New Mexico's smallest, live in Los Alamos or White Rock and the biggest employer is the Los Alamos National Laboratory.
MORE FROM FORBES: