Want to go to a US national park? You must bring a face mask

(CNN) — If you want to visit one of America's national parks, there's an essential item you must bring: face masks.

Showing that even wilderness areas aren't free from the reach of the Covid-19 Delta variant, the National Park Service announced Monday that it is immediately enforcing mask rules.

Visitors, employees and contractors are now required to wear a mask inside all NPS buildings and even in crowded outdoor spots. This applies regardless of your vaccination status or transmission levels within the community.

The NPS said it is following the latest science and guidance from the Centers for Disease Control and Prevention.

"Visitors to national parks are coming from locations across the country, if not across the world," said NPS Deputy Director Shawn Benge in a news release.

"Because of this, and recognizing that the majority of the United States is currently in substantial or high transmission categories, we are implementing a service-wide mask requirement to ensure our staff and visitors' safety."

The policy renews a mask mandate issued in February by the National Park Service.