Interior Secretary David Bernhardt is being urged to close all units of the National Park System, including Grand Canyon/NPS file

Editor's note: This updates with additional details on the situation at Grand Canyon National Park, with an effort being launched on social media to convince the Interior secretary to close the park.

Interior Secretary David Bernhardt faced renewed calls Tuesday to close down the National Park System in the face of the coronavirus pandemic, while at Grand Canyon National Park nerves were fraying among some workers who couldn't understand why the park remained open.

"It is frightening that you continue to allow and encourage park visitation," the Coalition to Protect America's National Parks told Bernhardt in a letter Tuesday. "Your inaction and failure to support the recommendations of experienced (National Park Service) managers and their local communities is putting NPS employees and local gateway community members at serious risk to exposure to the virus potentially carried by travelers from outside the local area."

Later in the day, U.S. Rep. Raúl Grijalva, who chairs the House Natural Resources Committee, and nine other Democrats sent a similar letter to Bernhardt, saying he should let superintendents on the ground make the call as to whether to close their parks.

"We understand that closing an iconic destination like the Grand Canyon is not an easy decision, but we implore you to do everything in your power to prioritize public health and not interfere with locally informed decisions to close parks where appropriate," they wrote.

Grand Canyon has been a trigger point for concern, and even outrage in some quarters, for units of the National Park System that remain open while dozens of others have closed.

According to staff at Grand Canyon, a case of COVID-19 within the park was confirmed on Monday. National Park Service staff in Washington said at least seven Park Service employees have received a COVID-19 diagnosis.

Back at the Grand Canyon, a maintenance worker awaiting his test results was said to still be working to clean bathrooms. Acting park Superintendent Mary Risser supposedly was teleworking out of her residence, while her staff went about its duties as usual in park offices and in the field. When she went out shopping, park staff would ask her to close the park, the Traveler was told by someone familiar with those exchanges.

There also was word that Bernhardt "told Grand Canyon that even the employees' spouses are not allowed to talk to the press about the situation there," a statement that was catching fire on social media.

"Did you really say 'someone needs to tell those wives at Grand Canyon to stay off of Facebook?' Because if you did, it seems to contradict the NPS emphasis on a respectful and inclusive work force," Karen Vandzura, who described herself as a "wife at Grand Canyon," wrote on the Interior secretary's Facebook page. "I also wonder why you would think it’s only wives? Or is it okay for husbands?"

Another who identified herself as a Grand Canyon wife, Kate Densmore, wrote on her Facebook page that on Saturday she counted vehicles from 22 different states in the park. 

"This is why it's so important that the parks close, especially one with as large a draw as Grand Canyon. I don't think I have to actually point out the danger our tiny community is in, having visitors from ALL OVER in our village right now," wrote Densmore. "Everyone is being urged to #stayhome, yet we have tourists from all over the country in our neighborhood. Using our grocery store, our post office, our bank, and our small walk-in clinic. And keep in mind how remote we are: our closest hospital bed is an hour and a half away."

While Arizona Gov. Doug Ducey issued a statewide "stay at home order" that was to take effect at 5 p.m. local time Tuesday, he exempted activities around "walking, hiking, running, biking, or golfing." He also blocked local communities from overriding the order. 

Local government entities have called for the Grand Canyon's closure; among them, the Coconino County Board of Supervisors, the Navajo Nation, Tusayan Chamber of Commerce, and the Tusayan Fire Department.

The Coalition believes more parks in addition to the Grand Canyon should close.

"Skyline Drive and its overlooks in Shenandoah National Park remain open despite Virginia Governor (Ralph) Northam’s stay-at-home order; and despite Virginia Department of Health documentation of multiple local cases of COVID-19 in counties surrounding the park," read the Coalition's letter to Bernhardt. "And park roads into Zion Canyon remain open in Zion National Park despite Utah Governor (Gary) Herbert’s stay-at-home order; and despite Utah Department of Health documentation of multiple local cases of COVID-19 in the Southwest Utah reporting area containing the park. It is, of course, predictable that visitors will escape the frustrations of confinement and visit popular trails and overlooks where park roads remain open."

That many parks are closed while others remain open doesn't make sense, continued the letter, which was signed by Phil Francis, the Coalition's chair.

"For park employees, and everyone who cares about them, the inconsistency between which parks remain open and which are closed is utterly mindboggling and defies rational explanation," it reads. "There is obviously a lack of clear guidance or leadership emanating from the Department and NPS leadership on this life-threatening crisis."

The letter was also sent to Rob Wallace, assistant secretary of the Interior, Fish, Wildlife and Parks, and David Vela, the de facto director of the National Park Service.

Grijalva and his colleagues stressed to Bernhardt that there are many areas within the National Park System that are struggling to meet CDC guidelines in terms of keeping park staff and visitors safe.

"As you know, impacts of the pandemic are not unique to Arizona and the Grand Canyon. In New Mexico, the All Pueblo Council of Governors has asked groups of visitors not to visit KashaKatuwe Tent Rocks National Monument because of the threat posed to the nearby Cochiti Pueblo," they wrote. "In Washington, D.C., streets and Metro stations near the National Mall and Tidal Basin had to be closed down to stem the crowds of people seeking to view the seasonal cherry blossoms.

"Thousands of people are going into Zion National Park every day and many of them continue to gather at Angels Landing, one of its more popular lookouts," they went on. "While we recognize that the National Park Service has closed a portion of Angels Landing trail due to crowding, the closure of entire parks in other areas has been necessitated by the fact that social distancing just isn’t possible on many of our most visited public lands, despite people’s best intentions."

While many parks have placed warnings on their websites about the coronavirus pandemic, the congressmen said those, along with the closure of some park facilities, "have not proven sufficient to protect public health, prompting grave concerns from federal employees and the local communities nearest our public lands. Many parks are located in rural areas where an outbreak would overrun community hospitals and their staff, making it imperative that we act now to reduce risk."

The letter was signed by Grijalva, and Reps. Deb Haaland (D-N.M),  Jared Huffman (D-Calif.), Alan Lowenthal (D-Calif.), Ruben Gallego (D-Ariz.), Darren Soto (D-Fla.), A. Donald McEachin (D-Va.), Diana DeGette (D-Colo.), Jesús G. “Chuy” Garcia (D-Ill.) and Tom O’Halleran (D-Ariz.)

Meanwhile, campgrounds at New River Gorge National River, Gauley River National Recreation Area, and Bluestone National Scenic River in West Virginia all closed Tuesday. Recent closures in the National Park System included Crater Lake National Park in Oregon, the campground at Obed National Wild and Scenic River in Tennessee, the Charles Young Buffalo Soliders National Monument in Ohio, the Little Bighorn Battlefield National Monument in Montana, and the San Francisco Maritime National Historical Park.

Joshua Tree National Park officials announced their park would be closed to all visitors on Wednesday.