Effective immediately, masks will be required at all park buildings and outdoor areas.

Heading to the Grand Canyon or Yellowstone any time soon? Then you're going to need a mask. Per recommendation by the Centers for Disease Control and Prevention, the National Park Service announced Monday that guests, staff, and contractors will be required to wear face coverings inside park buildings or in crowded outdoor spaces.

The mandate will be implemented regardless of one's vaccination status or community transmission.

The move follows in the wake of the contagious Delta variant spreading throughout the United States. According to the CDC, most of the nation maintains a "moderate" to "substantial" level of community spread. In a new update from the agency, masks are highly encouraged in public places where social distancing can't be practiced, even for those who are vaccinated.

“Visitors to national parks are coming from locations across the country, if not across the world," NPS Deputy Director Shawn Benge said in a press 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 agency operates over 400 parks, landmarks, and areas of historical interest across the country, many of which are tourist attractions. With larger crowds comes an increase in contact with others, thereby increasing the possibility of transmission. Captain Maria Said, MD, an epidemiologist for the agency's Office of Public Health, urges visitors to get the vaccine for the utmost protection against the virus.

“Being vaccinated is the most effective way to protect yourself and your loved ones from the dangers of the coronavirus," Said stated. "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."

The mandate begins immediately for all guests on the park premises. So if you're embarking on a trip soon, plan accordingly! You can take a look at the full guidance here.

What do you think of the National Park Service's decision? Sound off in the comments.