Former Baltimorean Greg Wise, who moved to York eight years ago to be closer to his aging parents, says he can easily identify new Maryland transplants who have joined him in the northern migration just across the Pennsylvania line.

They're called "white-taggers," he said, because they have yet to change over to Pennsylvania license plates. He estimates that about one-fourth of those commuting south on Interstate 83 with him every morning still have Maryland tags.

Long considered a Baltimore exurb, York County has seen its population swell 14 percent since 2000. The southern Pennsylvania county — a mix of urban, suburban and rural geography and home to many Baltimore-area commuters — grew faster than Maryland as a whole and twice as rapidly as Baltimore County in that time, according to new population figures from the 2010 census.

York's rise has many implications. Its population growth outpaced the rest of Pennsylvania as well, giving it more influence in the Legislature even as the state is expected to lose a seat in Congress. The addition of more people — 53,000 more — also means increasing racial diversity because many new residents are minorities. Some residents even note an influx of young professionals.

And as has been the case for years, York's gain can be Maryland's loss.York County's public transportation system, dubbed rabbittransit, expanded its I-83 South commuter bus service last week to Towson.

"I definitely get the feeling especially southern York County has become an extension of Baltimore County," said Wise, who drives each day to a job at Digital Harbor High School in South Baltimore.

Another way to ferret out a former Baltimorean in York, he adds: They still tend to socialize on their front steps even after they have gained a spacious, suburban rear lawn.

Marylanders have flocked to York for its bucolic setting and cheaper homes. About seven years ago, Nicole Russell, at the time a real estate agent in Maryland, noticed many of her newest clients were selling their homes to settle in the tiny townships that make up York County.

"I started losing business in Maryland because I wasn't licensed in Pennsylvania," Russell said.

When she and her husband, a Baltimore County police officer, decided to move from Northeast Baltimore to southern York County in 2006, the seeds of a new business had been planted. Years of research on the best schools and neighborhoods in the county persuaded her family to make the move, and Russell figured other Maryland transplants could use help in the transition.

"I've been able to make a business doing that because there are so many people going from Baltimore to York," Russell said.

The southern part of York County showed particularly strong growth in the past decade. And some of the fastest-growing areas there — including Loganville, Jacobus and Springfield Township — are known as favorite spots for Maryland transplants.

"The previous census told us the same thing," said Eric Menzer, chairman of the York County Community Foundation and a longtime developer in the city of York. "This now marks 20 years of rapid growth, which of course really started with the migration of the South."

Donna Sites, an agent with Southern Penn Real Estate in York and herself a former Maryland resident, said the attraction is the strong reputation of York schools and "substantially lower" cost of living. Sites, who came to the Loganville area from Glen Burnie, said that for the price she paid for a new house on three acres in York County, she would have been able to afford only an older Maryland home in need of extensive renovation.

"For a while, probably 80 percent of my clients were from Maryland," she said.

Russell, 44, said just two of more than 50 families living in her neighborhood are York County natives. The rest, she said, hail from Baltimore and its surrounding counties, and some of her neighbors commute as far south as Washington or Northern Virginia for work.

Her family also is one of two black families in her neighborhood, Russell said, and her children's schools are nearly all white. For all her preparation, she found herself unprepared for the lack of ethnic and racial diversity in wider York County.

While the numbers are minuscule compared with the Baltimore region, nearly every small township surrounding the city of York saw minority populations jump. Still, nearly 90 percent of county residents are white. In Jacobus, for instance, the Hispanic population has grown more than 2,000 percent since 2000 — to a grand total of 65 residents.

But in a place where some residents say it is not uncommon to see Confederate flags, even the modest demographic changes have caused some uneasiness. York was also the site of a deadly race riot in 1969, a scar that has taken decades to fade.