While almost every part of the country has been affected in some way by COVID-19, some parts have been hit much harder. As of May 19, there have been about 470 confirmed cases of coronavirus for every 100,000 Americans nationwide. In some counties, however, infections are far more common.

Using COVID-19 data from state and local health departments and population data from the U.S. Census Bureau, 24/7 Wall St. reviewed the number of confirmed COVID-19 cases in over 3,000 U.S. counties and county equivalents to determine the counties with the most confirmed cases, adjusted for population size.

While, unsurprisingly, there are a number of counties on this list in states like New York, New Jersey, and Massachusetts — which lead all states in confirmed cases per capita — the list also includes counties from states with relatively few confirmed cases per capita, including Oklahoma, Idaho, and Arkansas. These are the states with the highest numbers of COVID-19 cases.

In several counties on this list in states with relatively few infections per capita, large outbreaks in institutions like nursing homes and prisons have accounted for a large share of COVID-19 cases. According to the New York Times, one in three COVID-19-related deaths in the United States have been nursing home residents or workers. To help protect these high-risk populations, some states have discouraged or even banned state residents from visiting certain facilities. These are every state’s rules for staying at home and social distancing.

Click here to see the counties in every state with the highest number of COVID-19 cases