Bonnie Johnson, Franklin County's assistant county administrator, will be leaving Southwest Virginia's fastest growing locality to work in one of the state's smallest and most rural counties.

In August, Johnson will become the county administrator of Bath County.

Johnson, 62, has played key roles in developing Franklin County's public utilities, economic growth and landfill operations over the past 10 years. Before that, she worked as the county administrator of Cumberland County, an assistant county administrator in Botetourt County and a county planner in Roanoke County.

"The board of supervisors believes Ms. Johnson's background and experience will provide a solid resource to the community," Bath County supervisors' Chairman Richard Byrd said in a news release.

"It's a new opportunity, and I'm looking forward to a new challenge up there," Johnson said Thursday.

According to new population estimates produced by the University of Virginia's Weldon Cooper Center for Public Service, Franklin County's population, an estimated 50,100 people, was the fastest-growing community in the Roanoke region, increasing 5.9 percent in the past five years. Nearly all that growth came from newcomers moving to the area.

By contrast, Bath County has a population estimated at 4,900 people, according to the Weldon Cooper Center report. The rural locality, known mostly for its outdoor recreation opportunities and as the home of The Homestead Resort, lost 100 residents over the past five years.

"As I can see across the state, we all have similar challenges, and many of theirs are the same as we face here in Franklin County," Johnson said. "It's just they don't have as many people living there."

Bath County is part of what is known as the Alleghany Highlands, which also includes Alleghany and Highland counties, the city of Covington and the towns of Clifton Forge and Iron Gate.

While the area has suffered from a sluggish economy, government leaders among the localities have vowed to work together to attract more jobs.

Johnson will be paid about $82,000 in her new position. She replaces Claire Collins, who left in February after 14 years to become city manager of Covington.

"Her credentials were really good," interim Bath County administrator Clifford Williams said of Johnson. "We went through 18 different candidates. They brought her in for two different interviews and she was really great. I mean, really impressive."

Franklin County Administrator Rick Huff said Johnson will be sorely missed.

"Her institutional knowledge, her work ethic, her skill set will be difficult to replace," he said.

Staff writer Mason Adams contributed to this report.