The 81st annual motorcycle rally comes a year after roughly 460,000 attendees shunned masks and social distancing at an event that researchers associated with the Centers for Disease Control and Prevention concluded “had many characteristics of a superspreading event.” At least 649 covid-19 cases were linked to Sturgis, but the true total was obscured as contact tracing was difficult after bikers returned to their home states.

Although Sturgis’s coronavirus case numbers are relatively low, the CDC has designated Meade County, which includes the city, as an area of “high community transmission,” advising residents or visitors to wear masks in public indoor spaces. About 37 percent of Meade County is fully vaccinated, according to the CDC, and more than 47 percent of South Dakota is fully inoculated as of Friday.