DUFUR, Ore. (AP) — The social distancing rules repeated like a mantra in America's urban centers, where the coronavirus is spreading exponentially, might seem silly in wide-open places where neighbors live miles apart and "working from home" means another day spent branding calves or driving a tractor alone through a field.

But as the pandemic spreads through the U.S., those living in rural areas, too, are increasingly threatened. Tiny towns tucked into Oregon's windswept plains and cattle ranches miles from anywhere in South Dakota might not have had a single case of the new coronavirus, but...