Seventeen of "America's 25 Richest Counties" lie between Virginia and Long Island, but only one - Chester County - is in the Philadelphia area, according to a new list from Forbes magazine.

Chester County is 24th, with an average per-capita income of $84,844, well behind Loudon County, Va., ranked first with $110,643.

Virginia boasts eight of the top 25, followed by four in Maryland, and the proximity to big government is no coincidence.

"The federal government generates a wealth of jobs, keeping unemployment in the D.C. metro area at a low 6.2 percent," compared to the national average of 10 percent, writes Forbes' Francesca Levy.

The next biggest cluster is around New York City, with Hunterdon, Somerset and Morris Counties in New Jersey and Nassau, Putnam and Suffolk Counties in New York.

That could change next year, though, when fallout from the Wall Street's financial downturn is reflected in fresher data, according to Forbes.

Major cities don't make the list for a couple of reasons - lots of low-income people and paycheck flight.

"The country's riches tend to trickle away from big cities," according to Levy. "It's not major metro areas raking in the biggest salaries; rather, it's the tony suburbs just outside big-industry centers that soak up big-city money."

Despite lots of money on the West Coast and around other major U.S. cities, the list skews East Coast because it tends to have smaller, more homogeneous counties.

Just missing the "Richest Counties" list, for example, is Fort Bend County, Texas, a suburb of Houston, which topped Forbes' "Best Places to Get Ahead," a Top 10 list published in February.

From 2007 to 2008, household income there grew 10 percent and jobs over the last three years were up nearly 5 percent.

Almost "Richest" were the next two best "Get Ahead" places: Delaware County, Ohio, a Columbus suburb, and Kendall County, Ill., a Chicago suburb.

Only four counties appeared on both lists: Loudon and Arlington Counties in Virginia, Douglas County, Colo., and Alexandria City, Va.

No Pennsylvania or New Jersey counties were in the Top 10 for "Best Places to Get Ahead."

So would it be smart to move?

Not necessarily. "Where you choose to settle tends to be an extension of how much you make, rather than the other way around," Levy writes.

Besides, neither list factored in the higher cost of living around New York and Washington, D.C.

For example, the lifestyle maintained with the $100,000 median income of Fairfax, Va., only requires an income of $64,305 in Philadelphia, according to a calculator at www.bestplaces.net.

Here's the list of richest counties, according to Forbes:

1. Loudoun County, Va., $110,643.

2. Fairfax County, Va., $106,785.

3. Howard County, Md., $101,710.

4. Hunterdon County, N.J., $100,947.

5. Somerset County, N.J., $100,207.

6. Fairfax city, Va., $98,133.

7. Morris County, N.J., $97,565.

8. Douglas County, Colo., $97,480.

9. Arlington County, Va., $96,390.

10. Montgomery County, Md., $93,999.

11. Nassau County, N.Y., $93,579.

12. Stafford County, Va., $89,536.

13. Calvert County, Md., $89,049.

14. Prince William County, Va., $88,675.

15. Putnam County, N.Y., $88,580.

16. Goochland County, Va., $88,552.

17. Williamson County, Tenn., $88,316.

18. Marin County, Calif., $88,101.

19. Santa Clara County, Calif., $87,287.

20. Forsyth County, Ga., $86,938.

21. Charles County, Md., $86,586.

22. Summit County, Utah, $85,258.

23. Alexandria city, Va., $85,135.

24. Chester County, Pa. , $84,844.

25. Suffolk County, N.Y., $84,767.

For more about the lists, go to www.forbes.com.