The House Natural Resources Committee intends to investigate the Trump administration’s decision to dip into visitor fees to keep parks open, the panel's chairman warned Sunday.

Rep. Raúl Grijalva (D-Ariz.) said that his committee — which oversees Interior — has plans to look into the legality of the decision, saying the shutdown has done “terrible damage” to the U.S.

“President Trump Donald John TrumpBarr criticizes DOJ in speech declaring all agency power 'is invested in the attorney general' Military leaders asked about using heat ray on protesters outside White House: report Powell warns failure to reach COVID-19 deal could 'scar and damage' economy MORE and his advisors apparently just woke up to the fact that the shutdown they created several weeks ago has done terrible damage to our country,” Grijalva said in a statement Sunday.

“This is not how a rational president behaves, and the Natural Resources Committee will demand answers about whether these moves are legally justified.” ADVERTISEMENT

The National Park Service (NPS) announced to staff Sunday a plan to dip into “entrance, camping, parking and other fees collected from park visitors” to pay staff to assist in urgent maintenance needs at a number of national parks overburdened by visitors during the recent government shutdown.

“As the lapse in appropriations continues, it has become clear that highly visited parks with limited staff have urgent needs that cannot be addressed solely through the generosity of our partners,” Daniel Smith, NPS deputy director, said in a statement obtained by The Hill.

Smith said he and acting Interior Secretary David Bernhardt developed the plan to “address the maintenance and sanitation issues that have arisen at a number of highly visited parks.”

“We are taking this extraordinary step to ensure that parks are protected, and that visitors can continue to access parks with limited basic services,” the statement read.

Bernhardt signed a memorandum Saturday to use the fees known as Federal Lands Recreation Enhancement Act money, The Washington Post reported.

Jonathan Jarvis, who led the Park Service under President Obama from 2009 to 2017, slammed the strategy as a “significant departure” from how the agency has historically used the money parks.

“Since [the Federal Lands Recreation Enhancement Act’s] original passage, it’s always been interpreted by the Park Service as not available for operations,” said Jarvis, who worked in the agency for more than three decades, including as director of the Pacific West region.

“This is a significant departure. It wasn’t even a consideration during the 16-day shutdown when I was director,” he said, referring to the 2013 shutdown. “That’s eating your seed corn.”

Jarvis worried that using the fee money in this way would take it away from park maintenance, which has a backlog nearing $12 billion across the country.

Jarvis had officials close parks entirely during the 2013 shutdown, despite criticisms from Republicans and others. He’s been highly critical of the Trump administration’s strategy to keep them open with little to no staff.

“It sends a particular message that they don’t really care about the resource, and probably increasingly, they don’t seem to care about the visitor either,” he said. “They only seem to care about the bad press that they’re getting.”

The gates to most U.S. national parks were left open under the most recent shutdown, which has extended since Dec. 22. While visitors have been able to access parks, many services including bathrooms and trash pick-up was suspended as government employees were kept home. That’s created a number of headaches across the country at highly visited parks where trash is piling up, bathrooms are at capacity and visitors aren’t being watched by experts.

At least one park, Joshua Tree National Park in California, was shuttered due to "health and safety concerns."

While in the past access to national parks has been restricted during a shutdown due to safety concerns, former Interior Secretary Ryan Zinke Ryan Keith ZinkeTrump extends Florida offshore drilling pause, expands it to Georgia, South Carolina Conspicuous by their absence from the Republican Convention Trump flails as audience dwindles and ratings plummet MORE made keeping parks up a priority during his tenure.

During the last shutdown last January, Zinke told reporters the parks shouldn’t be used as a bargaining chip in shutdown negotiations.

“Our public lands and our monuments really belong to the people and not the government,” he told CNN.

He said however, “by law” Interior wasn’t allowed to provide clean up services to parks.

"Law enforcement is still there. But things like cleaning the bathrooms ... and telling the story of our parks, which is important — that side of it, while the 'Schumer shutdown' is in, by law we're not able to provide those services," Zinke said, mentioning the GOP label for the shutdown at the time.

In an interview earlier this week Zinke told The Associated Press that the public should “Pitch in, grab a trash bag and take some trash out.”

Zinke’s last day at Interior was Jan. 2. He resigned from the agency in December amid multiple ethics investigations.

However, Interior’s plan to dip from the fee pot was laid out clearly in its 2019 shutdown contingency plan, which read: “Parks that collect fees under the Federal Lands Recreation Enhancement Act (FLREA) will utilize available retained recreation fees balances to provide basic visitor services in a manner that maintains restrooms and sanitation, trash collection, road maintenance, campground operations, law enforcement and emergency operations, and staffing entrance gates as necessary to provide critical safety information.”

Spokesmen for Interior and NPS did not return requests for comment.

Critics are questioning the legality of Interior’s decision to use the park fees, money that is assigned by Congress to pay for other federal expenses, including the department’s multibillion-dollar maintenance backlog.

Theresa Pierno, president of the National Parks Conservation Association, called NPS’s action the equivalent of stealing.

“Instead of working to reopen the federal government, the administration is robbing money collected from entrance fees to operate our national parks during this shutdown,” she said in a statement.

“It’s incredibly concerning that the Acting Interior Secretary is putting political pressure on Superintendents to keep parks open at the expense of parks’ long-term needs and protection.”

Out of the 418 park units across the country, 165 collect fees, and they took in $285.2 million in fiscal year 2017, according to a report last year by the Congressional Research Service. Usually, at least 80 percent of that revenue has to stay with the park that took it in, and the rest can go to other parks.

At least one group, the National Park Hospitality Association, applauded the agency’s fee strategy. The organization represents companies that operate businesses in parks, like gift shops, restaurants and lodging.

“NPHA has actively supported visitor fee retention by federal recreation providers and use of collected funds for visitor-related purposes,” Scott Socha, the group’s chairman and president for parks and resorts at Delware North Cos., said in a statement.