LOS ANGELES (CNS) — The National Park Service mandated Monday that all visitors, employees and contractors must wear a mask inside NPS buildings and in crowded outdoor areas, regardless of vaccination status.

This mandate follows the recommendation of the U.S. Centers for Disease Control and Prevention, and will be in effect until further notice. The requirement applies to all NPS buildings, public transportation systems and outdoor spaces where physical distancing cannot be maintained, such as busy trails and overlooks.

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

Capt. Maria Said, an epidemiologist in the NPS Office of Public Health, added, "Masking in addition to being vaccinated will help prevent the spread of new variants and protect those who are more at risk of severe disease. This simple act of kindness allows us to be safe while we continue to enjoy the benefits of our national parks."