The National Park Service will be given congressional funding to retroactively pay for operational costs expended during the partial government shutdown, according to an internal NPS email obtained by the Hill.

During the 35-day shutdown, the NPS lost anywhere from $10 to $14 million in entrance fee revenue and drew additional funds from previously collected fees to cover operational costs while some parks were kept open.

Parks can collect "recreation fees" for things like entry and parking under the Federal Lands Recreation Enhancement Act. The NPS is instructed to spend 55 percent of collected recreation fees on deferred maintenance projects to help address the $11.6 billion (and counting) deferred maintenance backlog, according to Emily Douce, director of budget and appropriations for the National Parks Conservation Association's government affairs team.

It has not yet been reported how much total FLREA funding was expended to keep parks open during the shutdown, but the superintendent of Joshua Tree National Park estimated that the park used $200,000 to $300,000 of recreation fees during the shutdown.

"If you're taking a lot of that revenue and using it to do operational things like cleaning up trash and campgrounds and restrooms and so forth, then that would impact projects that are in the pipeline to address deferred maintenance and other visitor enhancement," Douce said.

If the NPS memo does not prove to be accurate and the shutdown resumes on February 15th, the NPS could potentially keep using FLREA funding to operate the parks until it's completely drained, Douce said. But if the memo is accurate, then parks will save hundreds of thousands, if not millions, of dollars that they can put toward deferred maintenance projects.