Citing a spike in COVID-19 cases and the severity of the Delta variant, the Bayfield County Health Department recommended Friday that all residents and visitors to the area wear face masks "when in indoors" or in enclosed settings while interacting with others that are not from one's household.

The move came as the county was identified as a area of substantial transmission, something the county said it shares with more than half of all U.S. counties.

"Substantial" transmission is the third level on the Centers for Disease Control and Prevention's four levels of community transmission, one below the highest level.

Neighboring Douglas County, home to Superior, was in the CDC's moderate category. Bayfield, Ashland, Washburn and Burnett counties area all in the substantial transmission category.

"Besides wearing a mask in public or in crowded settings, getting vaccinated against COVID-19 is the best way to protect yourself, your family and your community," the county health department said.