In New York’s Catskills region, residents still complain about government moves decades ago to seize land surrounding a key watershed. Yet fearful of the virus’s spread, a handful of rural counties have issued bluntly worded orders for second homeowners to stay away.

“We are a very strong property rights county,” said Shelly Johnson-Bennett, the planning and watershed affairs director for Delaware County, N.Y. “But we’re really trying to get people to understand how dire this is. We don’t want anyone to die.”

Door County officials decided last week to declare a public emergency for the interconnected web of communities that is home to about 27,000 full-time residents scattered across the 80-mile-long peninsula. The county had not yet registered any infections, but the declaration freed up resources in case people started getting sick.

Cars with out-of-state license plates were showing up in the little towns across the county where shops were still boarded up for the winter. Hundreds of vehicles, one county official said.

People started joking about shutting down access to bridges that lead to the northern part of the peninsula. As the days passed, the jokes turned serious with texts and emails sent to officials calling for checkpoints at the county borders to block anyone with out-of-state drivers’ licenses from entering. People were getting scared.

“We are trying to protect our own, if you will,” said David Lienau, chairman of the Door County board of supervisors.

That meant protecting Door County from people like Jennifer Miller LaRiccia who, her whole life, has considered herself one of Door County’s own.