Howard County ranks as the third-richest county in America based on 2010 Census Bureau data, according to a report by MainStreet.com.

County residents have a median household income of $101,771. The next highest Maryland county in the group is Montgomery with a median income of $89,155. The national average for median household income is $49,445.

Howard is one of only three counties in the United States found to have a six-figure median household income.

The median value of owner-occupied homes in Howard was $456,200.

"With an astounding 58.3% of residents holding a bachelor’s degree or higher, Howard County shows that higher education can pay," the article said.

Among the MainStreet.com top 15 are 10 counties from the D.C. metropolitan area:

1. Loudoun County, Va. - Median Household Income: $119,540
2. Fairfax County, Va. - Median Household Income: $103,010
3. Howard County, Md. - Median Household Income: $101,771
4. Hunterdon County, N.J. - Median Household Income: $97,874
5. Arlington County, Va. - Median Household Income: $94,986
6. Douglas County, Colo. - Median Household Income: $94,909
7. Stafford County, Va. - Median Household Income: $94,317
8. Somerset County, N.J. - Median Household Income: $94,270
9. Prince William County, Va. - Median Household Income: $92,655
10. Morris County, N.J. - Median Household Income: $91,469
11. Nassau County, N.Y. - Median Household Income: $91,104
12. Montgomery County, Md. - Median Household Income: $89,155
13. Calvert County, Md. - Median Household Income: $88,862
14. St. Mary's County, Md. - Median Household Income: $88,444
15. Charles County, Md. - Median Household Income: $87,007