Bad weather forcing Grand Canyon National Park visitors inside raised fears from some employees about catching coronavirus/Rebecca Latson file

Editor's note: This updates with news that the Washington Monument will close to the public on Saturday.

Concern over the spread of the novel coronavirus COVID-19 on Friday led to cancellation of the annual maple sugar festival at Indiana Dunes National Park, the planned closing of the Washington Monument on Saturday, and worry for park employees who must interact with visitors in the National Park System.

Though there was no announcement from the National Park Service headquarters in Washington, D.C., about additional closings, it was possible that facilities such as national seashore lighthouses, where visitors can be packed close together as they climb and descend, and possibly tours of Mammoth Cave and Carlsband, also would be shut down in the days ahead. Also uncertain was how crowds in lodges, restaurants, and cafeterias in the parks would be managed. Though the peak summer season is weeks off, spring break typically brings large crowds to parks such as Zion and Grand Canyon.

On a closed-to-the-public Facebook page used by Park Service employees, the overall sentiment Friday seemed to be frustration and anger that Park Service leadership had issued no guidance to the public or employees. Many of those who commented mentioned that their park operations were in violation of state guidelines restricting group gatherings

Whether the decision to cancel the Maple Sugar Time Festival, and to shutter the Washington Monument, would spur similar moves elsewhere in the park system was unknown. In Washington, National Park Service Deputy Director David Vela, the de facto director of the agency, was busy dealing with the situation and unavailable to discuss how the Park Service was responding to the sweeping epidemic.

At Delaware North Parks and Resorts, which operates in or near Grand Canyon National Park, Rocky Mountain National Park, Yosemite National Park, Yellowstone National Park, Sequoia and Kings Canyon national parks, Olympic National Park, and Shenandoah National Park, spokesman Glen White said the concessionaire was working closely with the Park Service on the matter.

"We are taking appropriate measures to help ensure guest and employee safety, which is our highest priority," he said in an email. "At the restaurants and lodging that we operate in the parks, we have taken actions to help prevent the spread of the coronavirus based on the guidance of the Centers for Disease Control and Prevention (CDC), including: Expanding sanitizing protocols and bolstering cleaning services throughout our operations; placing hand sanitizer stations at locations for use by guests and employees; posting notifications for our employees on the importance of handwashing; and advising associates who feel sick to remain at home."

Calls to the three other major park concessionaires -- Xanterra Parks & Resorts, Aramark, and Forever Resorts -- were not immediatley returned Friday afternoon.

National Park Service officials, who were said to be in close communications with concessionaires and other park partners, could not immediately say Friday evening whether the concessionaires would refund lodgings reservations canceled at the last minute by visitors increasingly concerned about falling ill in the parks.

At Indiana Dunes in Indiana, staff issued a release stating that, "(T)o protect public health and slow the spread of the COVID-19 novel coronavirus, the National Park Service is cancelling this weekend’s Maple Sugar Time Festival at Indiana Dunes National Park’s Chellberg Farm. The park’s Paul H. Douglas Center for Environmental Education has also been closed and all ranger-led public and school programs are cancelled until at least March 23."

"These actions have been taken based on the best available medical advice to limit gatherings of large numbers of people and to promote social distancing," the statement continued. "At this time, the park’s trails and beaches remain open to the public."

In a statement circulating around the park system, the agency said it was "actively monitoring developments related to the COVID-19 novel coronavirus and is consulting with relevant federal, state and local authorities, including the CDC, to get the most up to date information needed to protect the health of our visitors, volunteers and employees."

But Park Service employees and volunteers who come face-to-face with visitors in crowded parks were voicing concerns over their safety.

"Great Smoky Mountains National Park hosted 12.5 million visitors last year from all over the world. There are four visitor centers that each have about 8,500 people each day come through. If this is not a high risk for the virus, I don't know what is," Andy W said in a comment on the Traveler. "I have served the park as a volunteer for five years and I for one will not venture into a park visitor center until the danger has passed."

Another reader, Kathy, wrote that, "I work in a park with cultural resources. People, staff and visitors, are shoulder to shoulder in confined spaces. No changes to historic building tours?"

Andrew S., who didn't indicate which park he works at, said visiting the parks should be discouraged, "especially since visitors don't always practice basic hygiene, even prior to COVID. And now, our concessioner seems to be running low on soap and towels. Even though I've always been meticulous about hygiene doesn't mean that those around me including fellow NPS and visitors will. And there have instances in the past where people have invaded my personal zone, coming definitely closer than the recommended six foot blast radius. Just saying."

Janie West, who indicated she works at Grand Canyon National Park, responded to those who argued that national parks should stay open during the epidemic. She wrote that, "Obviously you are not up here working in close contact and collecting their money, dishes, linens and putting yourself at risk. We have thousands coming through the gates and with bad weather everyone is inside. We were able to make it through a government shutdown for weeks but due to greed we can't take a couple weeks to protect our Grand Canyon community and staff?"

The bulk of the comments posted on the Traveler, though, came from readers who wanted the parks to stay open.

"I agree with keeping the parks open," wrote Victoria in a comment that mirrored many others. "What better way to stay healthy and positive than being out in the fresh air and getting exercise? It keeps up the endorphins. Proven to be good for your health, mentally and physically."

"Leave them open!!! This is a rare opportunity for American Families to get out in the fresh air with their families, visit our beautiful treasured national parks and avoid foreign traveler competition," wrote Jojo Willey. "Schools are now closed and flights are cheap. I was thinking of renting a couple of RVs and taking the whole family. This is the best time for well Americans to enjoy these resources!"