WASHINGTON – Interior Secretary Ryan Zinke launched an unprecedented effort Wednesday to undertake the largest reorganization in the department’s 168-year history, moving to shift tens of thousands of workers to new locations and change the way the federal government manages more than 500 million acres of land and water across the country.

The proposal would divide the United States into 13 regions and centralize authority for different parts of Interior within those boundaries. The regions would be defined by watersheds and geographic basins, rather than individual states and the current boundaries that now guide Interior’s operations. This new structure would be accompanied by a dramatic shift in location of the headquarters of major bureaus within Interior, such as the Bureau of Land Management and the Bureau of Reclamation.

As part of the reorganization, Zinke brought 150 Senior Executive Service staffers to Washington this week to explain his proposal, get their input and split them into working groups that discussed ways to streamline the Bureau of Land Management, Bureau of Reclamation, Fish and Wildlife Service and other key agencies. Participants identified alternative cities outside Washington, Denver and Albuquerque where thousands of employees could live with suitable schools and homes they can afford. The department has 70,000 employees.

In a Wednesday interview with The Washington Post, Zinke said reorganization is his largest priority, in addition to shoring up the National Park Service’s crumbling infrastructure, with its $12 billion shortfall for maintenance of buildings, roads, bridges and other projects.

“If you look at the way we’re presently organized, all the bureaus under Interior have different regions . . . and are not aligned geographically,” Zinke said. For example, a single stream with trout and salmon can fall under the view of five separate agencies, one for each fish, another for a dam downstream and yet another to manage the water, and each generate reports that often conflict.

“There’s not a lot of opportunity to work as a team,” said Zinke, a former Navy SEAL who favors military-like precision. Interior needs 13 new reorganized regions to better manage land and water, he said, and to respond to crisis as a coordinated unit.

Moving thousands of employees around the country would require congressional authorization. Zinke said the Trump administration plans to negotiate the reorganization in the upcoming budget approval process. During the Great Depression, Congress had delegated “consolidation authority” to the president but then withdrew it when the law’s sunset provision was triggered in 1984.

“There will be hearings on the Hill, briefings of committees,” Zinke said. “We want the reorganization to be bipartisan. There will be a lot of my time spent on the Hill, talking to ranking members and chairmen. In the Senate, the appropriations committee was briefed last year on what the beginning of the reorganization will look like.”

Former interior secretary Sally Jewell was one of several people with knowledge of the department who expressed doubt that such a sweeping reorganization can work.

“I’m skeptical about the reorganization and its ability to serve the public more effectively,” Jewell said in an interview Wednesday. “Interior has a broad and diverse mission.”

The department isn’t centralized in certain cities without reason, Jewell said. Agencies share real estate and leases as a cost-cutting measure. Reorganizing could come with massive costs for an agency whose budget is being dramatically cut by President Donald Trump.

“This would be from moving people, giving up leases before maturity, potential severance costs, and substantial disruption to productivity,” Jewell said in an email. In the interview, she said: “Just trying to look at a map and saying we’re going to take Interior and organize it this way may be inconsistent with the mission of Interior.”

Jennifer Talhelm, a spokeswoman for Sen. Tom Udall, D-N.M., also raised questions about aspects of the plan.

“As this process moves along, Senator Udall will listen to his constituents and pose a long list of questions – including why Secretary Zinke proposes to split New Mexico into two regions, and what impacts this proposal will have on tribes, on the department’s partners and stakeholders, and on the agency’s workforce in the state,” she said in an email.

Interior officials have emphasized that some Democrats in Colorado like the concept of moving BLM headquarters to that state, a change that would involve the relocation of about 350 federal employees. Samantha Slater, a spokeswoman for Sen. Michael Bennet, D-Colo., said in an email he is “supportive of moving more of the federal government out of Washington, particularly to the West.”

But she added that such a move would have to enhance BLM’s work, and noted, “We would expect Secretary Zinke to consult with our office, as well as communities across Colorado, prior to releasing any proposals.”

The politics of moving employees is often difficult, Jewell said. Interior sought to consolidate the BLM offices for New Mexico and Arizona because the topography of the states is so similar. “Congress came after us. You would’ve thought we were ending the world as we knew it. Politicians came out of the woodwork,” Jewell said. “You throw up your hands and say it’s not worth it. If you’re a politician it looks like your district lost and another district won.

Any attempt to undertake a broad overhaul of Interior is likely to encounter some level of congressional opposition, and several Democratic senators expressed initial skepticism about the plan.

“This proposal is concerning because it appears to eliminate the Navajo Regional Office of the Bureau of Indian Affairs,” said Sen. Martin Heinrich, D-N.M. “A change of this magnitude should only come after extensive, meaningful government-to-government consultation with the affected tribes. On its face, this looks more like a dismantling than a reorganization.”

At a budget hearing in June, Zinke defended a $1.6 billion proposed budget cut at Interior, saying he planned to shave 4,000 positions from the workforce. In September, he said a third of Interior’s staff was “not loyal to the flag,” meaning the Trump administration.

Jewell cited those remarks. “I will say most people view this not as an attempt to streamline but an attempt to downsize” Interior’s workforce, she said.

Zinke said he regretted the way he framed the loyalty remark in a speech to mostly oil and gas industry executives because it left room for misinterpretation. He said reorganization is necessary and can be done.

“This is going to be a long process,” he said. He called the conference-like gathering at Interior a giant first step, “a very important meeting” where employees in field offices had “an opportunity to talk to me personally. I think most people were really enthusiastic.”

Interior is poised to move employees because 16 percent of its workforce is currently at retirement age, Zinke said. About 40 percent will be at retirement age in five years, he said. “We don’t have to RIF [reduction in force] anyone” through layoffs and other means, he said. As people retire, positions can be shifted from Denver or Washington to “to a position closer to the field,” Zinke said.

Many congressional Republicans have embraced the idea of moving large divisions of Interior out the nation’s capital. Colorado GOP Sen. Cory Gardner and Rep. Scott Tipton introduced companion bills in May that would relocate BLM’s headquarters to any one of a dozen Western states, though the legislation has yet to pass.

Katie Schoettler, deputy press secretary for House Committee on Natural Resources Chairman Rob Bishop, R-Utah, said in an email that the panel’s staffers “remain engaged with the department” on the topic of reorganization.

“Once more detailed plans are made available, the committee will be evaluating if statutory changes are necessary to achieve its objectives and improve accountability, effectiveness and transparency in the service the agency provides to the public,” she said.

Environmentalists, who have fought with Zinke on a number of fronts since he first took office, expressed skepticism at the idea of such a radical change in the department’s structure.

“A regional approach to managing Interior might indeed make sense, but the jury is out on this reorganization,” Sharon Buccino, senior director for lands at the Natural Resources Defense Council, said in an email. “Virtually everything Secretary Zinke has done to date has been to advance fossil fuel interests – above the stewardship of our public lands, preservation of wildlife and protection of clean air and water.”

While presidents have managed to change the way the federal government is structured in times of crisis, such as after the Sept. 11, 2001, terrorist attacks, other reorganization proposals have sputtered to a halt. In 2012 President Barack Obama proposed a much broader government reorganization, which would have established a new department charged with overseeing trade and investment, business and economic development, technology and innovation, and economic statistics.

That move would have combined the trade and commerce functions of the Commerce Department, the Small Business Administration, the Office of the U.S. Trade Representative, the Export-Import Bank, the Overseas Private Investment Corp. and the Trade and Development Agency into one department, while also folding in the Census Bureau, the Bureau of Economic Analysis and the Bureau of Labor Statistics. By contrast, the National Oceanic and Atmospheric Administration would have been transferred from Commerce to Interior. The plan failed to gain traction on Capitol Hill.