Despite the Washington area's slowing growth rate -- down to 1.5 percent last year from 1.9 percent the year before -- its counties are in good shape compared with the 33 percent

across the country that are losing population to old age and migration.

Nationwide, 1,135 of 3,143 counties saw more deaths than births, up from 880 in 2009, according to census data. Counties surrounding the District had thousands more births than deaths, however, and were being further buoyed by high immigration rates.

"Immigration is the highest I saw in the metro [area] for nine or 10 years," said William Frey, a senior fellow at the Brookings Institution's Metropolitan Policy Program. "That's going to be very important if the area continues to see the small domestic in-migration it had last year."

The fastest-growing counties, census data show, were in Texas and the Great Plains. While many local economies waned, an oil and gas boom in North Dakota and West Texas drew in tens of thousands of workers.

Frey called Texas the "hands-down" winner in terms of most migrants, adding that cities such as Charlotte, N.C., Atlanta and Orlando, Fla., also saw gains. He said that a sightly better housing market is allowing more people to pick up and move to areas with better economic situations.

"There are people that might have been holding back for a while," Frey said. "The migration patterns are opening up again." - Matt Connolly