Since the start of June, 14 states and Puerto Rico have recorded their highest-ever seven-day average of new coronavirus cases since the pandemic began, according to data tracked by The Washington Post: Alaska, Arizona, Arkansas, California, Florida, Kentucky, New Mexico, North Carolina, Mississippi, Oregon, South Carolina, Tennessee, Texas and Utah.

If the pandemic’s first wave burned through dense metro hubs such as New York City, Chicago and Detroit, the highest percentages of new cases are coming from places with much smaller populations: Lincoln County, Ore., an area of less than 50,000, has averaged 20 new daily cases; the Bear River Health District in northern Utah has averaged 78 new cases a day in the past week, most of them tied to an outbreak at a meat processing plant in the small town of Hyrum.

The increase of coronavirus cases in counties with fewer than 60,000 people is part of the trend of new infections surging across the rural United States. Health experts worry those areas, already short of resources before the pandemic, will struggle to track new cases with the infrastructure that remains.