Why is that? There are several clues in “Why North and South Dakota are suffering the worst Covid-19 epidemics in the US”.

“Unlike other states, South and North Dakota never fully closed down, with the Republican governors in each state resisting ever issuing a stay-at-home order. So most of each state remained open — allowing the virus to spread freely through bars, restaurants, parties, celebrations, rodeos, rallies, and other large gatherings. Among those potential spreading events was a motorcycle rally in Sturgis, South Dakota, in early August, which some experts now blame for a Covid-19 surge that followed in the region, particularly in the Upper Midwest.

Neither state has adopted a mask mandate, which research shows can help suppress the coronavirus. Based on some national data, both Dakotas have some of the lowest rates of mask-wearing in the US.

Bonny Specker, an epidemiologist at South Dakota State University, was blunt in her assessment of the situation in the Dakotas. “Federal and many state leaders have not implemented mandates or reinforced [public health agencies’] recommendations to prevent the spread of the virus,” she told me. ‘In South Dakota, the governor had the information needed to minimize the impact of this virus on the health of South Dakotans, but she ignored that information as well as national recommendations from the CDC.'”

It would be wrong to politicize a public health crisis of this magnitude by reiterating the “Republican Governors” point. So I won’t reiterate the “Republican Governors” point.