"As a former commander, the front line makes a difference. If the front line is healthy, the force is healthy," Zinke, a former Navy SEAL, told senators as he spent three days recently defending the budget before congressional committees. "We're looking at a plan to push resources from middle management headquarters back to where they belong and are most effective to the front line."
But the department was unable to provide tangible details about how this would affect staffing, or just what tourists might see.
"We're not at a point yet where we're executing a plan to meet the goal," said Tom Crosson, a spokesman for the National Park Service.
In an email, Heather Swift, an Interior Department spokeswoman, said more details will be available in the coming weeks.
"The Secretary's planned reorganization will allow the Department to push more resources to the front lines, AKA the local parks and field offices, by using 'joint management areas,'" Swift said.
That will mean "several land management agencies that operate in the same general area working more closely together to manage neighboring parcels of land. The secretary is drawing (on) his inspiration from the military where they have joint commands," she said.
President Donald Trump's budget request calls for a cut to the National Park Service, overseen by the Department of Interior, of almost $300 million for the 2018 fiscal year, about half of which would be money for park operations.
Sen. Maria Cantwell, D-Wash., said the budget would cut $881,000 from Mount Rainier National Park and $900,000 from Olympic National Park in her home state, a reduction of about 7 percent for each park.
"Can you explain why you think cutting these parks and support functions and park personnel who are on the front line is the right strategy in balancing, as you say, a budget?" Cantwell asked at a Senate committee hearing recently on the Interior budget.
Zinke responded by saying he's toured parks and monuments since becoming secretary, "and it's clear the front line is too thin. So my assessment of the Department of Interior is we have too many middle management and above and too few in the parks. And so we are looking at going through a process, (in) coordination with you, how to push more assets to (the) front line."
The budget requests $193 million for the central offices, which means more than half the staff would have to be eliminated to make up for the $143 million cut to park operations.
Sen. Steve Daines, R-Mont., said Trump's budget would cut $956,000 from Glacier National Park and $2.5 million to Yellowstone, also a cut of about 7 percent.
"I'm concerned as we see these national parks receiving record levels of visitation," Daines said at a Senate appropriations subcommittee hearing.
Data from the park service show national parks are more popular than ever. According to the budget justification, a record 323.6 million people visited the parks in the 2016 fiscal year.
Advocates for the parks are concerned.
"We would see the biggest damage to park operations since World War II," said John Garder, director of budget and appropriations for the National Parks Conservation Association, a non-profit headquartered in D.C.
Garder said the parks are already understaffed and that further layoffs could lead to reduced hour at visitor centers, longer lines at entrance stations, and elimination of family-friendly programs like campfire talks and nature walks. He said the cuts could also affect visitor safety through reductions in park police and other safety personnel.
"The budget is inconsistent with the statement that resources are being provided for the front line," he said.
Garder also said the middle management that Zinke wants to thin out provide important guidance and expertise on things like maintenance projects to the 59 national parks around the U.S.
"These aren't just bureaucrats, these are people that provide important services," he said.
Zinke also said he is looking at increasing revenue for the parks by having them charge more.
He said the department is looking at "public-private partnerships" in the parks by having private companies handle certain aspects of park operations like transportation.
Garder was critical of those moves, saying such partnerships are already used where they "make sense" and that access to the parks should not be based on means.
"These are public lands that are owned by all Americans," he said.