The virus' presence became ubiquitous in the United States. In mid-May, 231 of the nation's 3,143 counties had reported no cases of COVID-19. By mid-October, only six U.S. counties reported being COVID-free. This week, as the virus rages toward a third peak, with new infections concentrated in the Midwest and upwards of 50,000 cases a day nationwide, that number shrunk to four.
Those four are Loving County, Texas, Esmeralda County, Nevada, Skagway Municipality, Alaska, and Kalawao County, Hawaii.
The four counties in the United States that haven't reported a single COVID-19 case have some commonalities. They're sparsely populated and geographically isolated. They're solidly middle-class. In two counties, tourism has ground to a sudden halt because of the pandemic. But testing in areas without strong health infrastructure can complicate the picture, experts warn. You can't report COVID-19 cases if you don't test for them, and rural America has historically lacked access to health resources available in more populated areas.
From April: Life in areas with 0 confirmed coronavirus cases
"Is it that they don't have access?" asked Dr. Jorge Caballero, a clinical instructor at Stanford Medicine, who built a national testing directory that the federal government uses as part of its COVID-19 response effort. "Or are they so remote that they essentially serve as their own version of the NBA bubble?"
Rural and isolated areas are the opposite of a monolith. America's last COVID-free counties span the oil fields of Texas, high desert towns in Nevada, a popular Alaskan port city and a Hawaiian peninsula where historically, patients with leprosy were forced to live in isolation.
Experts warn against extrapolating too much from a tiny sample, in which geography, population density, luck, and even the way in which the United States counts infections, likely play big parts in their lack of coronavirus cases.
In conversations with ABC News, local officials had their own theories. Geography and a sparse population were a starting point. They learned lessons from cities with early outbreaks. Having a small population allowed the community to protect the most vulnerable. But they don't feel invincible, most said. On the contrary, they're testing and preparing. Whether they've been careful, lucky or divinely blessed, the virus is coming, they say.